diff --git a/include/m_ctype.h b/include/m_ctype.h
index 8673794356a06..215837972eb06 100644
--- a/include/m_ctype.h
+++ b/include/m_ctype.h
@@ -27,7 +27,8 @@
 enum loglevel {
    ERROR_LEVEL=       0,
    WARNING_LEVEL=     1,
-   INFORMATION_LEVEL= 2
+   INFORMATION_LEVEL= 2,
+   DEBUG_LEVEL=       3
 };
 
 #ifdef	__cplusplus
diff --git a/include/mysql/plugin_audit.h.pp b/include/mysql/plugin_audit.h.pp
index 3d57b383f10cc..d589948f526bc 100644
--- a/include/mysql/plugin_audit.h.pp
+++ b/include/mysql/plugin_audit.h.pp
@@ -128,22 +128,32 @@
   void (*logger_init_mutexes)();
   LOGGER_HANDLE* (*open)(const char *path,
                          unsigned long long size_limit,
+                         unsigned long long buffer_limit,
                          unsigned int rotations);
   int (*close)(LOGGER_HANDLE *log);
   int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
   int (*write)(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int (*rotate)(LOGGER_HANDLE *log);
+  int (*rotate)(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int (*rename_file)(LOGGER_HANDLE *log, const char *path);
+  int (*resize_buffer)(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int (*resize_size)(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int (*flush)(LOGGER_HANDLE *log);
 } *logger_service;
   void logger_init_mutexes();
   LOGGER_HANDLE *logger_open(const char *path,
                              unsigned long long size_limit,
+                             unsigned long long buffer_limit,
                              unsigned int rotations);
   int logger_close(LOGGER_HANDLE *log);
   int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
   int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int logger_rotate(LOGGER_HANDLE *log);
+  int logger_rotate(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int logger_rename_file(LOGGER_HANDLE *log, const char* path);
+  int logger_resize_buffer(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int logger_resize_size(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int logger_flush(LOGGER_HANDLE *log);
 }
 extern "C" {
 extern struct my_md5_service_st {
diff --git a/include/mysql/plugin_auth.h.pp b/include/mysql/plugin_auth.h.pp
index fbb4f5910ecf9..65a2f9e4a3cb4 100644
--- a/include/mysql/plugin_auth.h.pp
+++ b/include/mysql/plugin_auth.h.pp
@@ -128,22 +128,32 @@
   void (*logger_init_mutexes)();
   LOGGER_HANDLE* (*open)(const char *path,
                          unsigned long long size_limit,
+                         unsigned long long buffer_limit,
                          unsigned int rotations);
   int (*close)(LOGGER_HANDLE *log);
   int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
   int (*write)(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int (*rotate)(LOGGER_HANDLE *log);
+  int (*rotate)(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int (*rename_file)(LOGGER_HANDLE *log, const char *path);
+  int (*resize_buffer)(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int (*resize_size)(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int (*flush)(LOGGER_HANDLE *log);
 } *logger_service;
   void logger_init_mutexes();
   LOGGER_HANDLE *logger_open(const char *path,
                              unsigned long long size_limit,
+                             unsigned long long buffer_limit,
                              unsigned int rotations);
   int logger_close(LOGGER_HANDLE *log);
   int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
   int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int logger_rotate(LOGGER_HANDLE *log);
+  int logger_rotate(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int logger_rename_file(LOGGER_HANDLE *log, const char* path);
+  int logger_resize_buffer(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int logger_resize_size(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int logger_flush(LOGGER_HANDLE *log);
 }
 extern "C" {
 extern struct my_md5_service_st {
diff --git a/include/mysql/plugin_data_type.h.pp b/include/mysql/plugin_data_type.h.pp
index be20dcccd557a..c21e367404bb8 100644
--- a/include/mysql/plugin_data_type.h.pp
+++ b/include/mysql/plugin_data_type.h.pp
@@ -128,22 +128,32 @@
   void (*logger_init_mutexes)();
   LOGGER_HANDLE* (*open)(const char *path,
                          unsigned long long size_limit,
+                         unsigned long long buffer_limit,
                          unsigned int rotations);
   int (*close)(LOGGER_HANDLE *log);
   int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
   int (*write)(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int (*rotate)(LOGGER_HANDLE *log);
+  int (*rotate)(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int (*rename_file)(LOGGER_HANDLE *log, const char *path);
+  int (*resize_buffer)(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int (*resize_size)(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int (*flush)(LOGGER_HANDLE *log);
 } *logger_service;
   void logger_init_mutexes();
   LOGGER_HANDLE *logger_open(const char *path,
                              unsigned long long size_limit,
+                             unsigned long long buffer_limit,
                              unsigned int rotations);
   int logger_close(LOGGER_HANDLE *log);
   int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
   int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int logger_rotate(LOGGER_HANDLE *log);
+  int logger_rotate(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int logger_rename_file(LOGGER_HANDLE *log, const char* path);
+  int logger_resize_buffer(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int logger_resize_size(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int logger_flush(LOGGER_HANDLE *log);
 }
 extern "C" {
 extern struct my_md5_service_st {
diff --git a/include/mysql/plugin_encryption.h.pp b/include/mysql/plugin_encryption.h.pp
index 21edc27e4e350..b235dae1814ab 100644
--- a/include/mysql/plugin_encryption.h.pp
+++ b/include/mysql/plugin_encryption.h.pp
@@ -128,22 +128,32 @@
   void (*logger_init_mutexes)();
   LOGGER_HANDLE* (*open)(const char *path,
                          unsigned long long size_limit,
+                         unsigned long long buffer_limit,
                          unsigned int rotations);
   int (*close)(LOGGER_HANDLE *log);
   int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
   int (*write)(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int (*rotate)(LOGGER_HANDLE *log);
+  int (*rotate)(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int (*rename_file)(LOGGER_HANDLE *log, const char *path);
+  int (*resize_buffer)(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int (*resize_size)(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int (*flush)(LOGGER_HANDLE *log);
 } *logger_service;
   void logger_init_mutexes();
   LOGGER_HANDLE *logger_open(const char *path,
                              unsigned long long size_limit,
+                             unsigned long long buffer_limit,
                              unsigned int rotations);
   int logger_close(LOGGER_HANDLE *log);
   int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
   int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int logger_rotate(LOGGER_HANDLE *log);
+  int logger_rotate(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int logger_rename_file(LOGGER_HANDLE *log, const char* path);
+  int logger_resize_buffer(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int logger_resize_size(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int logger_flush(LOGGER_HANDLE *log);
 }
 extern "C" {
 extern struct my_md5_service_st {
diff --git a/include/mysql/plugin_ftparser.h.pp b/include/mysql/plugin_ftparser.h.pp
index 58b8274fcb0cc..5b09e059f279e 100644
--- a/include/mysql/plugin_ftparser.h.pp
+++ b/include/mysql/plugin_ftparser.h.pp
@@ -128,22 +128,32 @@
   void (*logger_init_mutexes)();
   LOGGER_HANDLE* (*open)(const char *path,
                          unsigned long long size_limit,
+                         unsigned long long buffer_limit,
                          unsigned int rotations);
   int (*close)(LOGGER_HANDLE *log);
   int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
   int (*write)(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int (*rotate)(LOGGER_HANDLE *log);
+  int (*rotate)(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int (*rename_file)(LOGGER_HANDLE *log, const char *path);
+  int (*resize_buffer)(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int (*resize_size)(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int (*flush)(LOGGER_HANDLE *log);
 } *logger_service;
   void logger_init_mutexes();
   LOGGER_HANDLE *logger_open(const char *path,
                              unsigned long long size_limit,
+                             unsigned long long buffer_limit,
                              unsigned int rotations);
   int logger_close(LOGGER_HANDLE *log);
   int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
   int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int logger_rotate(LOGGER_HANDLE *log);
+  int logger_rotate(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int logger_rename_file(LOGGER_HANDLE *log, const char* path);
+  int logger_resize_buffer(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int logger_resize_size(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int logger_flush(LOGGER_HANDLE *log);
 }
 extern "C" {
 extern struct my_md5_service_st {
diff --git a/include/mysql/plugin_function.h.pp b/include/mysql/plugin_function.h.pp
index f1c4ad93b33ac..d4f6396440880 100644
--- a/include/mysql/plugin_function.h.pp
+++ b/include/mysql/plugin_function.h.pp
@@ -128,22 +128,32 @@
   void (*logger_init_mutexes)();
   LOGGER_HANDLE* (*open)(const char *path,
                          unsigned long long size_limit,
+                         unsigned long long buffer_limit,
                          unsigned int rotations);
   int (*close)(LOGGER_HANDLE *log);
   int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
   int (*write)(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int (*rotate)(LOGGER_HANDLE *log);
+  int (*rotate)(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int (*rename_file)(LOGGER_HANDLE *log, const char *path);
+  int (*resize_buffer)(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int (*resize_size)(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int (*flush)(LOGGER_HANDLE *log);
 } *logger_service;
   void logger_init_mutexes();
   LOGGER_HANDLE *logger_open(const char *path,
                              unsigned long long size_limit,
+                             unsigned long long buffer_limit,
                              unsigned int rotations);
   int logger_close(LOGGER_HANDLE *log);
   int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
   int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int logger_rotate(LOGGER_HANDLE *log);
+  int logger_rotate(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int logger_rename_file(LOGGER_HANDLE *log, const char* path);
+  int logger_resize_buffer(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int logger_resize_size(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int logger_flush(LOGGER_HANDLE *log);
 }
 extern "C" {
 extern struct my_md5_service_st {
diff --git a/include/mysql/plugin_password_validation.h.pp b/include/mysql/plugin_password_validation.h.pp
index 5f9bd1b398933..2149783dd6c52 100644
--- a/include/mysql/plugin_password_validation.h.pp
+++ b/include/mysql/plugin_password_validation.h.pp
@@ -128,22 +128,32 @@
   void (*logger_init_mutexes)();
   LOGGER_HANDLE* (*open)(const char *path,
                          unsigned long long size_limit,
+                         unsigned long long buffer_limit,
                          unsigned int rotations);
   int (*close)(LOGGER_HANDLE *log);
   int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
   int (*write)(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int (*rotate)(LOGGER_HANDLE *log);
+  int (*rotate)(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int (*rename_file)(LOGGER_HANDLE *log, const char *path);
+  int (*resize_buffer)(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int (*resize_size)(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int (*flush)(LOGGER_HANDLE *log);
 } *logger_service;
   void logger_init_mutexes();
   LOGGER_HANDLE *logger_open(const char *path,
                              unsigned long long size_limit,
+                             unsigned long long buffer_limit,
                              unsigned int rotations);
   int logger_close(LOGGER_HANDLE *log);
   int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
   int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int logger_rotate(LOGGER_HANDLE *log);
+  int logger_rotate(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int logger_rename_file(LOGGER_HANDLE *log, const char* path);
+  int logger_resize_buffer(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int logger_resize_size(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int logger_flush(LOGGER_HANDLE *log);
 }
 extern "C" {
 extern struct my_md5_service_st {
diff --git a/include/mysql/service_logger.h b/include/mysql/service_logger.h
index 5979901bdd0c3..8b965c19601cd 100644
--- a/include/mysql/service_logger.h
+++ b/include/mysql/service_logger.h
@@ -24,17 +24,22 @@
   @file
   logger service
 
-  Log file with rotation implementation.
+  Log file with buffered writing and rotation implementation.
 
-  This service implements logging with possible rotation
-  of the log files. Interface intentionally tries to be similar to FILE*
-  related functions.
+  This service implements logging with possible buffered writing
+  and rotation of the log files. Interface intentionally tries to
+  be similar to FILE* related functions.
 
   So that one can open the log with logger_open(), specifying
-  the limit on the logfile size and the rotations number.
+  the limit on the logfile size, possible buffer size and the
+  rotations number.
+
+  If buffer size is given, messages are written to buffer.
+  If size of messages in buffer grow over the specified
+  limit, they are written to logfile.
 
   Then it's possible to write messages to the log with
-  logger_printf or logger_vprintf functions.
+  logger_printf, logger_vprintf or logger_write functions.
 
   As the size of the logfile grows over the specified limit,
   it is renamed to 'logfile.1'. The former 'logfile.1' becomes
@@ -63,37 +68,55 @@ extern struct logger_service_st {
   void (*logger_init_mutexes)();
   LOGGER_HANDLE* (*open)(const char *path,
                          unsigned long long size_limit,
+                         unsigned long long buffer_limit,
                          unsigned int rotations);
   int (*close)(LOGGER_HANDLE *log);
   int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
   int (*write)(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int (*rotate)(LOGGER_HANDLE *log);
+  int (*rotate)(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int (*rename_file)(LOGGER_HANDLE *log, const char *path);
+  int (*resize_buffer)(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int (*resize_size)(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int (*flush)(LOGGER_HANDLE *log);
 } *logger_service;
 
 #ifdef MYSQL_DYNAMIC_PLUGIN
 
 #define logger_init_mutexes logger_service->logger_init_mutexes
-#define logger_open(path, size_limit, rotations) \
-  (logger_service->open(path, size_limit, rotations))
+#define logger_open(path, size_limit, buffer_limit, rotations)	\
+  (logger_service->open(path, size_limit, buffer_limit, rotations))
 #define logger_close(log) (logger_service->close(log))
-#define logger_rotate(log) (logger_service->rotate(log))
+#define logger_rotate(log, rotations) (logger_service->rotate(log, rotations))
 #define logger_vprintf(log, fmt, argptr) (logger_service->\
     vprintf(log, fmt, argptr))
 #define logger_printf (*logger_service->printf)
 #define logger_write(log, buffer, size) \
   (logger_service->write(log, buffer, size))
+#define logger_rename_file(log, path) \
+  (logger_service->rename_file(log, path))
+#define logger_resize_buffer(log, buffer_limit) \
+  (logger_service->resize_buffer(log, path))
+#define logger_resize_size(log, size_limit) \
+  (logger_service->resize_size(log, size_limit))
+#define logger_flush(log) \
+  (logger_service->flush(log))
 #else
 
   void logger_init_mutexes();
   LOGGER_HANDLE *logger_open(const char *path,
                              unsigned long long size_limit,
+                             unsigned long long buffer_limit,
                              unsigned int rotations);
   int logger_close(LOGGER_HANDLE *log);
   int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
   int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
   int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size);
-  int logger_rotate(LOGGER_HANDLE *log); 
+  int logger_rotate(LOGGER_HANDLE *log, const unsigned int n_rotations);
+  int logger_rename_file(LOGGER_HANDLE *log, const char* path);
+  int logger_resize_buffer(LOGGER_HANDLE *log, unsigned long long buffer_limit);
+  int logger_resize_size(LOGGER_HANDLE *log, unsigned long long size_limit);
+  int logger_flush(LOGGER_HANDLE *log);
 #endif
 
 
diff --git a/include/wsrep.h b/include/wsrep.h
index e4535deabfe5c..e5ab917399353 100644
--- a/include/wsrep.h
+++ b/include/wsrep.h
@@ -23,11 +23,17 @@
 #define IF_WSREP(A,B) A
 #define DBUG_ASSERT_IF_WSREP(A) DBUG_ASSERT(A)
 
-extern ulong wsrep_debug; // wsrep_mysqld.cc
+/** wsrep_debug_mode is controlled by wsrep_debug and
+wsrep_buffered_error_log_buffer_size variables.
+If any of these are set we output also debug messages. */
+extern ulong wsrep_debug_mode; // wsrep_var.cc
+
 extern void WSREP_LOG(void (*fun)(const char* fmt, ...), const char* fmt, ...);
 
-#define WSREP_DEBUG(...)                                                \
-    if (wsrep_debug)     WSREP_LOG(sql_print_information, ##__VA_ARGS__)
+#define WSREP_DEBUG(...)                              \
+    if (wsrep_debug_mode)                             \
+      WSREP_LOG(sql_print_debug, ##__VA_ARGS__)
+
 #define WSREP_INFO(...)  WSREP_LOG(sql_print_information, ##__VA_ARGS__)
 #define WSREP_WARN(...)  WSREP_LOG(sql_print_warning,     ##__VA_ARGS__)
 #define WSREP_ERROR(...) WSREP_LOG(sql_print_error,       ##__VA_ARGS__)
@@ -47,7 +53,7 @@ extern void WSREP_LOG(void (*fun)(const char* fmt, ...), const char* fmt, ...);
             );
 
 #define WSREP_LOG_CONFLICT(bf_thd, victim_thd, bf_abort)                \
-  if (wsrep_debug || wsrep_log_conflicts)                               \
+  if (wsrep_debug_mode || wsrep_log_conflicts)                          \
   {                                                                     \
     WSREP_INFO("cluster conflict due to %s for threads:",               \
                (bf_abort) ? "high priority abort" : "certification failure" \
diff --git a/mysql-test/include/galera_variables_ok.inc b/mysql-test/include/galera_variables_ok.inc
index e420b3af6c30b..3dc9c65566954 100644
--- a/mysql-test/include/galera_variables_ok.inc
+++ b/mysql-test/include/galera_variables_ok.inc
@@ -1,6 +1,6 @@
 --disable_query_log
 
---let $galera_variables_ok = `SELECT COUNT(*) = 51 FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES WHERE VARIABLE_NAME LIKE 'wsrep%'`
+--let $galera_variables_ok = `SELECT COUNT(*) = 53 FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES WHERE VARIABLE_NAME LIKE 'wsrep%'`
 
 --if (!$galera_variables_ok) {
 	--skip Galera number of variables has changed!
diff --git a/mysql-test/include/galera_variables_ok_debug.inc b/mysql-test/include/galera_variables_ok_debug.inc
index e420b3af6c30b..3dc9c65566954 100644
--- a/mysql-test/include/galera_variables_ok_debug.inc
+++ b/mysql-test/include/galera_variables_ok_debug.inc
@@ -1,6 +1,6 @@
 --disable_query_log
 
---let $galera_variables_ok = `SELECT COUNT(*) = 51 FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES WHERE VARIABLE_NAME LIKE 'wsrep%'`
+--let $galera_variables_ok = `SELECT COUNT(*) = 53 FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES WHERE VARIABLE_NAME LIKE 'wsrep%'`
 
 --if (!$galera_variables_ok) {
 	--skip Galera number of variables has changed!
diff --git a/mysql-test/include/send_kill_to_mysqld.inc b/mysql-test/include/send_kill_to_mysqld.inc
new file mode 100644
index 0000000000000..857426daece90
--- /dev/null
+++ b/mysql-test/include/send_kill_to_mysqld.inc
@@ -0,0 +1,38 @@
+# ==== Purpose ====
+#
+# send kill signal to mysqld process.
+#
+# ==== Usage ====
+#
+# [--let $_kill_signal= 9]
+# --source include/send_kill_to_mysqld.inc
+#
+# Parameters:
+#
+#   $_kill_signal
+#     Which signal should be sent to mysqld. (default: 9 / SIGKILL)
+
+if ($_kill_signal == '')
+{
+  --let $_kill_signal = 9
+}
+--echo Sending kill signal $_kill_signal to mysqld ...
+
+# Write file to make mysql-test-run.pl expect the crash, but don't start it
+--source include/expect_crash.inc
+
+# Kill the connected server
+--disable_reconnect
+--let KILL_NODE_PIDFILE = `SELECT @@pid_file`
+--let KILL_SIGNAL = $_kill_signal
+--perl
+  my $pid_filename = $ENV{'KILL_NODE_PIDFILE'};
+  my $mysqld_pid = `cat $pid_filename`;
+  my $kill_signal = $ENV{'KILL_SIGNAL'};
+  chomp($mysqld_pid);
+  chomp($kill_signal);
+  system("kill -$kill_signal $mysqld_pid");
+  exit(0);
+EOF
+
+--source include/wait_until_disconnected.inc
diff --git a/mysql-test/suite/galera/r/galera_defaults.result b/mysql-test/suite/galera/r/galera_defaults.result
index 56c45b71632ca..14a5cd41f089f 100644
--- a/mysql-test/suite/galera/r/galera_defaults.result
+++ b/mysql-test/suite/galera/r/galera_defaults.result
@@ -19,6 +19,10 @@ ORDER BY VARIABLE_NAME;
 VARIABLE_NAME	VARIABLE_VALUE
 WSREP_ALLOWLIST	
 WSREP_AUTO_INCREMENT_CONTROL	ON
+WSREP_BUFFERED_ERROR_LOG_BUFFER_SIZE	0
+WSREP_BUFFERED_ERROR_LOG_FILENAME	
+WSREP_BUFFERED_ERROR_LOG_FILE_SIZE	0
+WSREP_BUFFERED_ERROR_LOG_ROTATIONS	10
 WSREP_CERTIFICATION_RULES	strict
 WSREP_CERTIFY_NONPK	ON
 WSREP_CLUSTER_ADDRESS	gcomm://
diff --git a/mysql-test/suite/galera/r/galera_var_buffered_error_log_buffer_size.result b/mysql-test/suite/galera/r/galera_var_buffered_error_log_buffer_size.result
new file mode 100644
index 0000000000000..6ebcf93580533
--- /dev/null
+++ b/mysql-test/suite/galera/r/galera_var_buffered_error_log_buffer_size.result
@@ -0,0 +1,86 @@
+connection node_2;
+connection node_1;
+connection node_2;
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+102400
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+4194304
+CREATE TABLE t1(a int not null primary key) engine=innodb;
+INSERT INTO t1 SELECT * FROM seq_1_to_1000;
+# Change buffer size larger
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 202400;
+SHOW WARNINGS;
+Level	Code	Message
+Testing that old log contains something logged
+FOUND 1 /WSREP: Loading provider/ in galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+202400
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+4194304
+SELECT COUNT(*) AS EXPECT_1000 FROM t1;
+EXPECT_1000
+1000
+DROP TABLE t1;
+# Change buffer size smaller
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 102400;
+SHOW WARNINGS;
+Level	Code	Message
+Testing that log contains something logged
+FOUND 4 /DROP TABLE/ in galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+102400
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+4194304
+# Try to change buffer size to unsupported size i.e too large
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 4194400;
+ERROR 42000: Variable 'wsrep_buffered_error_log_buffer_size' can't be set to the value of '4194400'
+SHOW WARNINGS;
+Level	Code	Message
+Warning	1231	Parameter 'wsrep_buffered_error_log_size' should be at range 102400-419430 because wsrep_buffered_error_log_file_size=4194304
+Error	1231	Variable 'wsrep_buffered_error_log_buffer_size' can't be set to the value of '4194400'
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+102400
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+4194304
+# Try to change buffer size to unsupported size i.e too small
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 8196;
+ERROR 42000: Variable 'wsrep_buffered_error_log_buffer_size' can't be set to the value of '8196'
+SHOW WARNINGS;
+Level	Code	Message
+Warning	1231	Parameter 'wsrep_buffered_error_log_size' should be at range 102400-419430 because wsrep_buffered_error_log_file_size=4194304
+Error	1231	Variable 'wsrep_buffered_error_log_buffer_size' can't be set to the value of '8196'
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+102400
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+4194304
+# Reset buffer size to original size
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 102400;
+SHOW WARNINGS;
+Level	Code	Message
+Warning	1231	Parameter 'wsrep_buffered_error_log_size' should be at range 102400-419430 because wsrep_buffered_error_log_file_size=4194304
+Error	1231	Variable 'wsrep_buffered_error_log_buffer_size' can't be set to the value of '8196'
diff --git a/mysql-test/suite/galera/r/galera_var_buffered_error_log_file_size.result b/mysql-test/suite/galera/r/galera_var_buffered_error_log_file_size.result
new file mode 100644
index 0000000000000..cacac77cad304
--- /dev/null
+++ b/mysql-test/suite/galera/r/galera_var_buffered_error_log_file_size.result
@@ -0,0 +1,56 @@
+connection node_2;
+connection node_1;
+connection node_2;
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+10240
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+204800
+CREATE TABLE t1(a int not null primary key auto_increment, count int) engine=innodb;
+# Change file size larger
+SET GLOBAL wsrep_buffered_error_log_file_size=262144;
+# List error log files - should have 3 files
+galera_buffered_error_log.err
+galera_buffered_error_log.err.1
+galera_buffered_error_log.err.2
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+10240
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+262144
+SELECT COUNT(*) AS EXPECT_2000 FROM t1;
+EXPECT_2000
+2000
+DROP TABLE t1;
+# Change file size smaller
+SET GLOBAL wsrep_buffered_error_log_file_size=131072;
+# List error log files - should be 3 files
+galera_buffered_error_log.err
+galera_buffered_error_log.err.1
+galera_buffered_error_log.err.2
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+10240
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+131072
+# Try to change buffer size to unsupported size i.e too small
+SET GLOBAL wsrep_buffered_error_log_file_size=1024;
+ERROR 42000: Variable 'wsrep_buffered_error_log_file_size' can't be set to the value of '1024'
+# Reset file size to original size
+SET GLOBAL wsrep_buffered_error_log_file_size=204800;
+# List error log files - should be 3 files
+galera_buffered_error_log.err
+galera_buffered_error_log.err.1
+galera_buffered_error_log.err.2
diff --git a/mysql-test/suite/galera/r/galera_var_buffered_error_log_filename.result b/mysql-test/suite/galera/r/galera_var_buffered_error_log_filename.result
new file mode 100644
index 0000000000000..913465fdf6c12
--- /dev/null
+++ b/mysql-test/suite/galera/r/galera_var_buffered_error_log_filename.result
@@ -0,0 +1,33 @@
+connection node_2;
+connection node_1;
+connection node_2;
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+102400
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+1048576
+CREATE TABLE t1(a int not null primary key) engine=innodb;
+INSERT INTO t1 SELECT * FROM seq_1_to_1000;
+# Change file name
+Testing that old log contains something logged
+FOUND 1 /WSREP: Loading provider/ in galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log2.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+102400
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+1048576
+SELECT COUNT(*) AS EXPECT_1000 FROM t1;
+EXPECT_1000
+1000
+DROP TABLE t1;
+# Change file name back to original
+Testing that second log contains something logged
+FOUND 4 /DROP TABLE/ in galera_buffered_error_log2.err
diff --git a/mysql-test/suite/galera/r/galera_var_buffered_error_log_rotations.result b/mysql-test/suite/galera/r/galera_var_buffered_error_log_rotations.result
new file mode 100644
index 0000000000000..edf8167149c9c
--- /dev/null
+++ b/mysql-test/suite/galera/r/galera_var_buffered_error_log_rotations.result
@@ -0,0 +1,69 @@
+connection node_2;
+connection node_1;
+connection node_2;
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+10240
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+102400
+SELECT @@global.wsrep_buffered_error_log_rotations;
+@@global.wsrep_buffered_error_log_rotations
+5
+CREATE TABLE t1(a int not null primary key auto_increment, count int) engine=innodb;
+# List error log files - max file number .5
+galera_buffered_error_log.err
+galera_buffered_error_log.err.1
+galera_buffered_error_log.err.2
+galera_buffered_error_log.err.3
+galera_buffered_error_log.err.4
+galera_buffered_error_log.err.5
+# Change rotations larger
+SET GLOBAL wsrep_buffered_error_log_rotations=6;
+# List error log files - max file number .6
+galera_buffered_error_log.err
+galera_buffered_error_log.err.1
+galera_buffered_error_log.err.2
+galera_buffered_error_log.err.3
+galera_buffered_error_log.err.4
+galera_buffered_error_log.err.5
+galera_buffered_error_log.err.6
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+10240
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+102400
+SELECT @@global.wsrep_buffered_error_log_rotations;
+@@global.wsrep_buffered_error_log_rotations
+6
+# Change rotations smaller and use different name
+SET GLOBAL wsrep_buffered_error_log_rotations=2;
+SELECT COUNT(*) AS EXPECT_2000 FROM t1;
+EXPECT_2000
+3000
+DROP TABLE t1;
+# List error log files - max file number .2
+galera_buffered_error_log2.err
+galera_buffered_error_log2.err.1
+galera_buffered_error_log2.err.2
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+galera_buffered_error_log2.err
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+10240
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+102400
+SELECT @@global.wsrep_buffered_error_log_rotations;
+@@global.wsrep_buffered_error_log_rotations
+2
+# Reset
+SET @@global.wsrep_buffered_error_log_rotations=5;
diff --git a/mysql-test/suite/galera/t/galera_var_buffered_error_log_buffer_size.cnf b/mysql-test/suite/galera/t/galera_var_buffered_error_log_buffer_size.cnf
new file mode 100644
index 0000000000000..edb6815695cd5
--- /dev/null
+++ b/mysql-test/suite/galera/t/galera_var_buffered_error_log_buffer_size.cnf
@@ -0,0 +1,9 @@
+!include ../galera_2nodes.cnf
+
+[mysqld]
+wsrep-debug=1
+
+[mysqld.2]
+wsrep_buffered_error_log_buffer_size=100K
+wsrep_buffered_error_log_file_size=4M
+wsrep_buffered_error_log_filename="galera_buffered_error_log.err"
diff --git a/mysql-test/suite/galera/t/galera_var_buffered_error_log_buffer_size.test b/mysql-test/suite/galera/t/galera_var_buffered_error_log_buffer_size.test
new file mode 100644
index 0000000000000..409b2588189f6
--- /dev/null
+++ b/mysql-test/suite/galera/t/galera_var_buffered_error_log_buffer_size.test
@@ -0,0 +1,69 @@
+--source include/galera_cluster.inc
+--source include/have_sequence.inc
+
+--connection node_2
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+CREATE TABLE t1(a int not null primary key) engine=innodb;
+INSERT INTO t1 SELECT * FROM seq_1_to_1000;
+
+--echo # Change buffer size larger
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 202400;
+SHOW WARNINGS;
+
+--echo Testing that old log contains something logged
+--let SEARCH_FILE= $MYSQLTEST_VARDIR/mysqld.2/data/galera_buffered_error_log.err
+--let ABORT_ON = NOT_FOUND
+--let SEARCH_PATTERN=WSREP: Loading provider
+--source include/search_pattern_in_file.inc
+
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+SELECT COUNT(*) AS EXPECT_1000 FROM t1;
+DROP TABLE t1;
+
+--echo # Change buffer size smaller
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 102400;
+SHOW WARNINGS;
+
+--echo Testing that log contains something logged
+--let SEARCH_FILE= $MYSQLTEST_VARDIR/mysqld.2/data/galera_buffered_error_log.err
+--let ABORT_ON = NOT_FOUND
+--let SEARCH_PATTERN=DROP TABLE
+--source include/search_pattern_in_file.inc
+
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+--echo # Try to change buffer size to unsupported size i.e too large
+--error ER_WRONG_VALUE_FOR_VAR
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 4194400;
+SHOW WARNINGS;
+
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+--echo # Try to change buffer size to unsupported size i.e too small
+--error ER_WRONG_VALUE_FOR_VAR
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 8196;
+SHOW WARNINGS;
+
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+--echo # Reset buffer size to original size
+SET GLOBAL wsrep_buffered_error_log_buffer_size = 102400;
+SHOW WARNINGS;
+
diff --git a/mysql-test/suite/galera/t/galera_var_buffered_error_log_file_size.cnf b/mysql-test/suite/galera/t/galera_var_buffered_error_log_file_size.cnf
new file mode 100644
index 0000000000000..93d029970fb78
--- /dev/null
+++ b/mysql-test/suite/galera/t/galera_var_buffered_error_log_file_size.cnf
@@ -0,0 +1,13 @@
+!include ../galera_2nodes.cnf
+
+[mysqld]
+wsrep-debug=1
+
+[mysqld.2]
+wsrep_buffered_error_log_buffer_size=10K
+wsrep_buffered_error_log_file_size=200K
+wsrep_buffered_error_log_filename="galera_buffered_error_log.err"
+wsrep_buffered_error_log_rotations=2
+loose-galera-log_file-size
+
+
diff --git a/mysql-test/suite/galera/t/galera_var_buffered_error_log_file_size.test b/mysql-test/suite/galera/t/galera_var_buffered_error_log_file_size.test
new file mode 100644
index 0000000000000..4a7ae5e3a1601
--- /dev/null
+++ b/mysql-test/suite/galera/t/galera_var_buffered_error_log_file_size.test
@@ -0,0 +1,69 @@
+--source include/galera_cluster.inc
+--source include/have_sequence.inc
+--source include/force_restart.inc
+
+--connection node_2
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+CREATE TABLE t1(a int not null primary key auto_increment, count int) engine=innodb;
+
+--let $inserts=1000
+--let $count=0
+--disable_query_log
+while($count < $inserts)
+{
+  --eval insert into t1 values (NULL,$count)
+  --eval update t1 set count = $count+100 where count = $count
+  --inc $count
+}
+--enable_query_log
+
+--echo # Change file size larger
+SET GLOBAL wsrep_buffered_error_log_file_size=262144;
+
+--echo # List error log files - should have 3 files
+--list_files $MYSQLTEST_VARDIR/mysqld.2/data galera_buffered_error_log*
+
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+--let $inserts=1000
+--let $count=0
+--disable_query_log
+while($count < $inserts)
+{
+  --eval insert into t1 values (NULL,$count)
+  --eval update t1 set count = $count+100 where count = $count
+  --inc $count
+}
+--enable_query_log
+
+SELECT COUNT(*) AS EXPECT_2000 FROM t1;
+DROP TABLE t1;
+
+--echo # Change file size smaller
+SET GLOBAL wsrep_buffered_error_log_file_size=131072;
+
+--echo # List error log files - should be 3 files
+--list_files $MYSQLTEST_VARDIR/mysqld.2/data galera_buffered_error_log*
+
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+--echo # Try to change buffer size to unsupported size i.e too small
+--error ER_WRONG_VALUE_FOR_VAR
+SET GLOBAL wsrep_buffered_error_log_file_size=1024;
+
+--echo # Reset file size to original size
+SET GLOBAL wsrep_buffered_error_log_file_size=204800;
+
+--echo # List error log files - should be 3 files
+--list_files $MYSQLTEST_VARDIR/mysqld.2/data galera_buffered_error_log*
+
diff --git a/mysql-test/suite/galera/t/galera_var_buffered_error_log_filename.cnf b/mysql-test/suite/galera/t/galera_var_buffered_error_log_filename.cnf
new file mode 100644
index 0000000000000..8171a3fc4f258
--- /dev/null
+++ b/mysql-test/suite/galera/t/galera_var_buffered_error_log_filename.cnf
@@ -0,0 +1,9 @@
+!include ../galera_2nodes.cnf
+
+[mysqld]
+wsrep-debug=1
+
+[mysqld.2]
+wsrep_buffered_error_log_buffer_size=100Kb
+wsrep_buffered_error_log_file_size=1M
+wsrep_buffered_error_log_filename="galera_buffered_error_log.err"
diff --git a/mysql-test/suite/galera/t/galera_var_buffered_error_log_filename.test b/mysql-test/suite/galera/t/galera_var_buffered_error_log_filename.test
new file mode 100644
index 0000000000000..b9884d2394424
--- /dev/null
+++ b/mysql-test/suite/galera/t/galera_var_buffered_error_log_filename.test
@@ -0,0 +1,41 @@
+--source include/galera_cluster.inc
+--source include/have_sequence.inc
+
+--connection node_2
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+CREATE TABLE t1(a int not null primary key) engine=innodb;
+INSERT INTO t1 SELECT * FROM seq_1_to_1000;
+
+--echo # Change file name
+--disable_query_log
+--eval SET GLOBAL wsrep_buffered_error_log_filename="galera_buffered_error_log2.err"
+--enable_query_log
+
+--echo Testing that old log contains something logged
+--let SEARCH_FILE= $MYSQLTEST_VARDIR/mysqld.2/data/galera_buffered_error_log.err
+--let ABORT_ON = NOT_FOUND
+--let SEARCH_PATTERN=WSREP: Loading provider
+--source include/search_pattern_in_file.inc
+
+--replace_regex /.*galera_buffered_error_log2.err.*/galera_buffered_error_log2.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+SELECT COUNT(*) AS EXPECT_1000 FROM t1;
+DROP TABLE t1;
+
+--echo # Change file name back to original
+--disable_query_log
+--eval SET GLOBAL wsrep_buffered_error_log_filename="galera_buffered_error_log.err"
+--enable_query_log
+
+--echo Testing that second log contains something logged
+--let SEARCH_FILE= $MYSQLTEST_VARDIR/mysqld.2/data/galera_buffered_error_log2.err
+--let ABORT_ON = NOT_FOUND
+--let SEARCH_PATTERN=DROP TABLE
+--source include/search_pattern_in_file.inc
diff --git a/mysql-test/suite/galera/t/galera_var_buffered_error_log_rotations.cnf b/mysql-test/suite/galera/t/galera_var_buffered_error_log_rotations.cnf
new file mode 100644
index 0000000000000..9e22940f2789f
--- /dev/null
+++ b/mysql-test/suite/galera/t/galera_var_buffered_error_log_rotations.cnf
@@ -0,0 +1,13 @@
+!include ../galera_2nodes.cnf
+
+[mysqld]
+wsrep-debug=1
+
+[mysqld.2]
+wsrep_buffered_error_log_buffer_size=10K
+wsrep_buffered_error_log_file_size=100K
+wsrep_buffered_error_log_filename="galera_buffered_error_log.err"
+wsrep_buffered_error_log_rotations=5
+loose-galera-log_rotations
+
+
diff --git a/mysql-test/suite/galera/t/galera_var_buffered_error_log_rotations.test b/mysql-test/suite/galera/t/galera_var_buffered_error_log_rotations.test
new file mode 100644
index 0000000000000..c50773f009a02
--- /dev/null
+++ b/mysql-test/suite/galera/t/galera_var_buffered_error_log_rotations.test
@@ -0,0 +1,86 @@
+--source include/galera_cluster.inc
+--source include/have_sequence.inc
+--source include/force_restart.inc
+
+--connection node_2
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+SELECT @@global.wsrep_buffered_error_log_rotations;
+
+CREATE TABLE t1(a int not null primary key auto_increment, count int) engine=innodb;
+
+--let $inserts=1000
+--let $count=0
+--disable_query_log
+while($count < $inserts)
+{
+  --eval insert into t1 values (NULL,$count)
+  --eval update t1 set count = $count+100 where count = $count
+  --inc $count
+}
+--enable_query_log
+
+--echo # List error log files - max file number .5
+--list_files $MYSQLTEST_VARDIR/mysqld.2/data galera_buffered_error_log*
+
+--echo # Change rotations larger
+SET GLOBAL wsrep_buffered_error_log_rotations=6;
+
+--let $inserts=1000
+--let $count=0
+--disable_query_log
+while($count < $inserts)
+{
+  --eval insert into t1 values (NULL,$count)
+  --eval update t1 set count = $count+100 where count = $count
+  --inc $count
+}
+--enable_query_log
+
+--echo # List error log files - max file number .6
+--list_files $MYSQLTEST_VARDIR/mysqld.2/data galera_buffered_error_log*
+
+--replace_regex /.*galera_buffered_error_log.err.*/galera_buffered_error_log.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+SELECT @@global.wsrep_buffered_error_log_rotations;
+
+--echo # Change rotations smaller and use different name
+--disable_query_log
+--eval SET GLOBAL wsrep_buffered_error_log_filename="galera_buffered_error_log2.err"
+--enable_query_log
+SET GLOBAL wsrep_buffered_error_log_rotations=2;
+
+--let $inserts=1000
+--let $count=0
+--disable_query_log
+while($count < $inserts)
+{
+  --eval insert into t1 values (NULL,$count)
+  --eval update t1 set count = $count+100 where count = $count
+  --inc $count
+}
+--enable_query_log
+
+SELECT COUNT(*) AS EXPECT_2000 FROM t1;
+DROP TABLE t1;
+
+--echo # List error log files - max file number .2
+--list_files $MYSQLTEST_VARDIR/mysqld.2/data galera_buffered_error_log2*
+
+--replace_regex /.*galera_buffered_error_log2.err.*/galera_buffered_error_log2.err/
+SELECT @@global.wsrep_buffered_error_log_filename;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+SELECT @@global.wsrep_buffered_error_log_rotations;
+
+--echo # Reset
+--disable_query_log
+--eval SET GLOBAL wsrep_buffered_error_log_filename="galera_buffered_error_log.err"
+--enable_query_log
+SET @@global.wsrep_buffered_error_log_rotations=5;
+
+
diff --git a/mysql-test/suite/sys_vars/r/sysvars_wsrep.result b/mysql-test/suite/sys_vars/r/sysvars_wsrep.result
index 9310119071c9a..4e49ccc56d01e 100644
--- a/mysql-test/suite/sys_vars/r/sysvars_wsrep.result
+++ b/mysql-test/suite/sys_vars/r/sysvars_wsrep.result
@@ -31,6 +31,66 @@ ENUM_VALUE_LIST	OFF,ON
 READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	OPTIONAL
 GLOBAL_VALUE_PATH	NULL
+VARIABLE_NAME	WSREP_BUFFERED_ERROR_LOG_BUFFER_SIZE
+SESSION_VALUE	NULL
+GLOBAL_VALUE	0
+GLOBAL_VALUE_ORIGIN	COMPILE-TIME
+DEFAULT_VALUE	0
+VARIABLE_SCOPE	GLOBAL
+VARIABLE_TYPE	BIGINT UNSIGNED
+VARIABLE_COMMENT	Size of the buffered error log buffer
+NUMERIC_MIN_VALUE	0
+NUMERIC_MAX_VALUE	18446744073709551615
+NUMERIC_BLOCK_SIZE	1
+ENUM_VALUE_LIST	NULL
+READ_ONLY	NO
+COMMAND_LINE_ARGUMENT	REQUIRED
+GLOBAL_VALUE_PATH	NULL
+VARIABLE_NAME	WSREP_BUFFERED_ERROR_LOG_FILENAME
+SESSION_VALUE	NULL
+GLOBAL_VALUE	
+GLOBAL_VALUE_ORIGIN	COMPILE-TIME
+DEFAULT_VALUE	
+VARIABLE_SCOPE	GLOBAL
+VARIABLE_TYPE	VARCHAR
+VARIABLE_COMMENT	Filename of the buffered error log
+NUMERIC_MIN_VALUE	NULL
+NUMERIC_MAX_VALUE	NULL
+NUMERIC_BLOCK_SIZE	NULL
+ENUM_VALUE_LIST	NULL
+READ_ONLY	NO
+COMMAND_LINE_ARGUMENT	REQUIRED
+GLOBAL_VALUE_PATH	NULL
+VARIABLE_NAME	WSREP_BUFFERED_ERROR_LOG_FILE_SIZE
+SESSION_VALUE	NULL
+GLOBAL_VALUE	0
+GLOBAL_VALUE_ORIGIN	COMPILE-TIME
+DEFAULT_VALUE	0
+VARIABLE_SCOPE	GLOBAL
+VARIABLE_TYPE	BIGINT UNSIGNED
+VARIABLE_COMMENT	Max size of the buffered error log file
+NUMERIC_MIN_VALUE	0
+NUMERIC_MAX_VALUE	18446744073709551615
+NUMERIC_BLOCK_SIZE	1
+ENUM_VALUE_LIST	NULL
+READ_ONLY	NO
+COMMAND_LINE_ARGUMENT	REQUIRED
+GLOBAL_VALUE_PATH	NULL
+VARIABLE_NAME	WSREP_BUFFERED_ERROR_LOG_ROTATIONS
+SESSION_VALUE	NULL
+GLOBAL_VALUE	10
+GLOBAL_VALUE_ORIGIN	COMPILE-TIME
+DEFAULT_VALUE	10
+VARIABLE_SCOPE	GLOBAL
+VARIABLE_TYPE	INT UNSIGNED
+VARIABLE_COMMENT	Number of log rotations before log is removed
+NUMERIC_MIN_VALUE	0
+NUMERIC_MAX_VALUE	999999
+NUMERIC_BLOCK_SIZE	1
+ENUM_VALUE_LIST	NULL
+READ_ONLY	NO
+COMMAND_LINE_ARGUMENT	REQUIRED
+GLOBAL_VALUE_PATH	NULL
 VARIABLE_NAME	WSREP_CERTIFICATION_RULES
 SESSION_VALUE	NULL
 GLOBAL_VALUE	strict
diff --git a/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_buffer_size_basic.result b/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_buffer_size_basic.result
new file mode 100644
index 0000000000000..5b11b3c869e06
--- /dev/null
+++ b/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_buffer_size_basic.result
@@ -0,0 +1,39 @@
+SET @start_value = @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @start_value;
+@start_value
+0
+SET @@global.wsrep_buffered_error_log_buffer_size = 102400;
+ERROR 42000: Variable 'wsrep_buffered_error_log_buffer_size' can't be set to the value of '102400'
+SHOW WARNINGS;
+Level	Code	Message
+Warning	1231	Cannot set 'wsrep_buffered_error_log_size' to a value other than 0 because wsrep is switched off.
+Error	1231	Variable 'wsrep_buffered_error_log_buffer_size' can't be set to the value of '102400'
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
+SET @@global.wsrep_buffered_error_log_buffer_size = 0;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
+SET @@session.wsrep_buffered_error_log_buffer_size = 0;
+ERROR HY000: Variable 'wsrep_buffered_error_log_buffer_size' is a GLOBAL variable and should be set with SET GLOBAL
+SELECT @@session.wsrep_buffered_error_log_buffer_size;
+ERROR HY000: Variable 'wsrep_buffered_error_log_buffer_size' is a GLOBAL variable
+SET @@global.wsrep_buffered_error_log_buffer_size = -10;
+Warnings:
+Warning	1292	Truncated incorrect wsrep_buffered_error_log_buff... value: '-10'
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
+SET @@global.wsrep_buffered_error_log_buffer_size = "/foo/bar.txt";
+ERROR 42000: Incorrect argument type to variable 'wsrep_buffered_error_log_buffer_size'
+SHOW WARNINGS;
+Level	Code	Message
+Error	1232	Incorrect argument type to variable 'wsrep_buffered_error_log_buffer_size'
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
+SET @@global.wsrep_buffered_error_log_buffer_size = @start_value;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
diff --git a/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_file_size_basic.result b/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_file_size_basic.result
new file mode 100644
index 0000000000000..db5b6132c1d83
--- /dev/null
+++ b/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_file_size_basic.result
@@ -0,0 +1,39 @@
+SET @start_value = @@global.wsrep_buffered_error_log_file_size;
+SELECT @start_value;
+@start_value
+0
+SET @@global.wsrep_buffered_error_log_file_size = 420;
+ERROR 42000: Variable 'wsrep_buffered_error_log_file_size' can't be set to the value of '420'
+SHOW WARNINGS;
+Level	Code	Message
+Warning	1231	Cannot set 'wsrep_buffered_error_log_file_size' to a value other than 0 because wsrep is switched off.
+Error	1231	Variable 'wsrep_buffered_error_log_file_size' can't be set to the value of '420'
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+0
+SET @@global.wsrep_buffered_error_log_file_size = 0;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+0
+SET @@session.wsrep_buffered_error_log_file_size = 0;
+ERROR HY000: Variable 'wsrep_buffered_error_log_file_size' is a GLOBAL variable and should be set with SET GLOBAL
+SELECT @@session.wsrep_buffered_error_log_file_size;
+ERROR HY000: Variable 'wsrep_buffered_error_log_file_size' is a GLOBAL variable
+SET @@global.wsrep_buffered_error_log_file_size = -10;
+Warnings:
+Warning	1292	Truncated incorrect wsrep_buffered_error_log_file... value: '-10'
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+0
+SET @@global.wsrep_buffered_error_log_file_size = "/foo/bar.txt";
+ERROR 42000: Incorrect argument type to variable 'wsrep_buffered_error_log_file_size'
+SHOW WARNINGS;
+Level	Code	Message
+Error	1232	Incorrect argument type to variable 'wsrep_buffered_error_log_file_size'
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+0
+SET @@global.wsrep_buffered_error_log_file_size = @start_value;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+@@global.wsrep_buffered_error_log_file_size
+0
diff --git a/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_filename_basic.result b/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_filename_basic.result
new file mode 100644
index 0000000000000..2eca2753434e8
--- /dev/null
+++ b/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_filename_basic.result
@@ -0,0 +1,30 @@
+SET @start_value = @@global.wsrep_buffered_error_log_filename;
+SELECT @start_value;
+@start_value
+NULL
+SET @size_start_value = @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @size_start_value;
+@size_start_value
+0
+SET @@global.wsrep_buffered_error_log_filename = "/tmp/bar.txt";
+ERROR 42000: Variable 'wsrep_buffered_error_log_filename' can't be set to the value of '/tmp/bar.txt'
+SHOW WARNINGS;
+Level	Code	Message
+Warning	1231	Cannot set 'wsrep_buffered_error_log_filename' because wsrep is switched off.
+Error	1231	Variable 'wsrep_buffered_error_log_filename' can't be set to the value of '/tmp/bar.txt'
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+NULL
+SET @@global.wsrep_buffered_error_log_filename = '';
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+
+SET @@session.wsrep_buffered_error_log_filename = OFF;
+ERROR HY000: Variable 'wsrep_buffered_error_log_filename' is a GLOBAL variable and should be set with SET GLOBAL
+SELECT @@session.wsrep_buffered_error_log_filename;
+ERROR HY000: Variable 'wsrep_buffered_error_log_filename' is a GLOBAL variable
+SET @@global.wsrep_buffered_error_log_filename = @start_value;
+SET @@global.wsrep_buffered_error_log_buffer_size = @size_start_value;
+SELECT @@global.wsrep_buffered_error_log_filename;
+@@global.wsrep_buffered_error_log_filename
+NULL
diff --git a/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_rotations_basic.result b/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_rotations_basic.result
new file mode 100644
index 0000000000000..5b11b3c869e06
--- /dev/null
+++ b/mysql-test/suite/sys_vars/r/wsrep_buffered_error_log_rotations_basic.result
@@ -0,0 +1,39 @@
+SET @start_value = @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @start_value;
+@start_value
+0
+SET @@global.wsrep_buffered_error_log_buffer_size = 102400;
+ERROR 42000: Variable 'wsrep_buffered_error_log_buffer_size' can't be set to the value of '102400'
+SHOW WARNINGS;
+Level	Code	Message
+Warning	1231	Cannot set 'wsrep_buffered_error_log_size' to a value other than 0 because wsrep is switched off.
+Error	1231	Variable 'wsrep_buffered_error_log_buffer_size' can't be set to the value of '102400'
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
+SET @@global.wsrep_buffered_error_log_buffer_size = 0;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
+SET @@session.wsrep_buffered_error_log_buffer_size = 0;
+ERROR HY000: Variable 'wsrep_buffered_error_log_buffer_size' is a GLOBAL variable and should be set with SET GLOBAL
+SELECT @@session.wsrep_buffered_error_log_buffer_size;
+ERROR HY000: Variable 'wsrep_buffered_error_log_buffer_size' is a GLOBAL variable
+SET @@global.wsrep_buffered_error_log_buffer_size = -10;
+Warnings:
+Warning	1292	Truncated incorrect wsrep_buffered_error_log_buff... value: '-10'
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
+SET @@global.wsrep_buffered_error_log_buffer_size = "/foo/bar.txt";
+ERROR 42000: Incorrect argument type to variable 'wsrep_buffered_error_log_buffer_size'
+SHOW WARNINGS;
+Level	Code	Message
+Error	1232	Incorrect argument type to variable 'wsrep_buffered_error_log_buffer_size'
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
+SET @@global.wsrep_buffered_error_log_buffer_size = @start_value;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+@@global.wsrep_buffered_error_log_buffer_size
+0
diff --git a/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_buffer_size_basic.test b/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_buffer_size_basic.test
new file mode 100644
index 0000000000000..a2631b340c3aa
--- /dev/null
+++ b/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_buffer_size_basic.test
@@ -0,0 +1,29 @@
+--source include/have_wsrep.inc
+
+SET @start_value = @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @start_value;
+
+--error ER_WRONG_VALUE_FOR_VAR
+SET @@global.wsrep_buffered_error_log_buffer_size = 102400;
+SHOW WARNINGS;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SET @@global.wsrep_buffered_error_log_buffer_size = 0;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+
+--error ER_GLOBAL_VARIABLE
+SET @@session.wsrep_buffered_error_log_buffer_size = 0;
+--Error ER_INCORRECT_GLOBAL_LOCAL_VAR
+SELECT @@session.wsrep_buffered_error_log_buffer_size;
+
+# No error, truncation
+SET @@global.wsrep_buffered_error_log_buffer_size = -10;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+
+--error ER_WRONG_TYPE_FOR_VAR
+SET @@global.wsrep_buffered_error_log_buffer_size = "/foo/bar.txt";
+SHOW WARNINGS;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+
+SET @@global.wsrep_buffered_error_log_buffer_size = @start_value;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+
diff --git a/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_file_size_basic.test b/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_file_size_basic.test
new file mode 100644
index 0000000000000..8f0d129506d95
--- /dev/null
+++ b/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_file_size_basic.test
@@ -0,0 +1,29 @@
+--source include/have_wsrep.inc
+
+SET @start_value = @@global.wsrep_buffered_error_log_file_size;
+SELECT @start_value;
+
+--error ER_WRONG_VALUE_FOR_VAR
+SET @@global.wsrep_buffered_error_log_file_size = 420;
+SHOW WARNINGS;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+SET @@global.wsrep_buffered_error_log_file_size = 0;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+--error ER_GLOBAL_VARIABLE
+SET @@session.wsrep_buffered_error_log_file_size = 0;
+--Error ER_INCORRECT_GLOBAL_LOCAL_VAR
+SELECT @@session.wsrep_buffered_error_log_file_size;
+
+# No error, truncation
+SET @@global.wsrep_buffered_error_log_file_size = -10;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+--error ER_WRONG_TYPE_FOR_VAR
+SET @@global.wsrep_buffered_error_log_file_size = "/foo/bar.txt";
+SHOW WARNINGS;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
+SET @@global.wsrep_buffered_error_log_file_size = @start_value;
+SELECT @@global.wsrep_buffered_error_log_file_size;
+
diff --git a/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_filename_basic.test b/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_filename_basic.test
new file mode 100644
index 0000000000000..f15ce05156f39
--- /dev/null
+++ b/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_filename_basic.test
@@ -0,0 +1,24 @@
+--source include/have_wsrep.inc
+
+SET @start_value = @@global.wsrep_buffered_error_log_filename;
+SELECT @start_value;
+SET @size_start_value = @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @size_start_value;
+
+--error ER_WRONG_VALUE_FOR_VAR
+SET @@global.wsrep_buffered_error_log_filename = "/tmp/bar.txt";
+SHOW WARNINGS;
+SELECT @@global.wsrep_buffered_error_log_filename;
+SET @@global.wsrep_buffered_error_log_filename = '';
+SELECT @@global.wsrep_buffered_error_log_filename;
+
+
+--Error ER_GLOBAL_VARIABLE
+SET @@session.wsrep_buffered_error_log_filename = OFF;
+--Error ER_INCORRECT_GLOBAL_LOCAL_VAR
+SELECT @@session.wsrep_buffered_error_log_filename;
+
+
+SET @@global.wsrep_buffered_error_log_filename = @start_value;
+SET @@global.wsrep_buffered_error_log_buffer_size = @size_start_value;
+SELECT @@global.wsrep_buffered_error_log_filename;
diff --git a/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_rotations_basic.test b/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_rotations_basic.test
new file mode 100644
index 0000000000000..a2631b340c3aa
--- /dev/null
+++ b/mysql-test/suite/sys_vars/t/wsrep_buffered_error_log_rotations_basic.test
@@ -0,0 +1,29 @@
+--source include/have_wsrep.inc
+
+SET @start_value = @@global.wsrep_buffered_error_log_buffer_size;
+SELECT @start_value;
+
+--error ER_WRONG_VALUE_FOR_VAR
+SET @@global.wsrep_buffered_error_log_buffer_size = 102400;
+SHOW WARNINGS;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+SET @@global.wsrep_buffered_error_log_buffer_size = 0;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+
+--error ER_GLOBAL_VARIABLE
+SET @@session.wsrep_buffered_error_log_buffer_size = 0;
+--Error ER_INCORRECT_GLOBAL_LOCAL_VAR
+SELECT @@session.wsrep_buffered_error_log_buffer_size;
+
+# No error, truncation
+SET @@global.wsrep_buffered_error_log_buffer_size = -10;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+
+--error ER_WRONG_TYPE_FOR_VAR
+SET @@global.wsrep_buffered_error_log_buffer_size = "/foo/bar.txt";
+SHOW WARNINGS;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+
+SET @@global.wsrep_buffered_error_log_buffer_size = @start_value;
+SELECT @@global.wsrep_buffered_error_log_buffer_size;
+
diff --git a/mysql-test/suite/wsrep/r/variables.result b/mysql-test/suite/wsrep/r/variables.result
index 9a3c4169ac83b..9ae934f5e9ade 100644
--- a/mysql-test/suite/wsrep/r/variables.result
+++ b/mysql-test/suite/wsrep/r/variables.result
@@ -1,72 +1,73 @@
 # Correct Galera library found
 SHOW GLOBAL STATUS LIKE 'wsrep%';
 Variable_name	Value
-wsrep_local_state_uuid	#
-wsrep_protocol_version	#
-wsrep_last_committed	#
-wsrep_replicated	#
-wsrep_replicated_bytes	#
-wsrep_repl_keys	#
-wsrep_repl_keys_bytes	#
-wsrep_repl_data_bytes	#
-wsrep_repl_other_bytes	#
-wsrep_received	#
-wsrep_received_bytes	#
-wsrep_local_commits	#
-wsrep_local_cert_failures	#
-wsrep_local_replays	#
-wsrep_local_send_queue	#
-wsrep_local_send_queue_max	#
-wsrep_local_send_queue_min	#
-wsrep_local_send_queue_avg	#
-wsrep_local_recv_queue	#
-wsrep_local_recv_queue_max	#
-wsrep_local_recv_queue_min	#
-wsrep_local_recv_queue_avg	#
-wsrep_local_cached_downto	#
-wsrep_flow_control_paused_ns	#
-wsrep_flow_control_paused	#
-wsrep_flow_control_sent	#
-wsrep_flow_control_recv	#
-wsrep_flow_control_active	#
-wsrep_flow_control_requested	#
-wsrep_cert_deps_distance	#
+wsrep_applier_thread_count	#
 wsrep_apply_oooe	#
 wsrep_apply_oool	#
-wsrep_apply_window	#
 wsrep_apply_waits	#
-wsrep_commit_oooe	#
-wsrep_commit_oool	#
-wsrep_commit_window	#
-wsrep_local_state	#
-wsrep_local_state_comment	#
+wsrep_apply_window	#
+wsrep_causal_reads	#
+wsrep_cert_deps_distance	#
 wsrep_cert_index_size	#
 wsrep_cert_interval	#
-wsrep_open_transactions	#
-wsrep_open_connections	#
-wsrep_incoming_addresses	#
+wsrep_cluster_capabilities	#
+wsrep_cluster_conf_id	#
+wsrep_cluster_size	#
+wsrep_cluster_state_uuid	#
+wsrep_cluster_status	#
 wsrep_cluster_weight	#
+wsrep_commit_oooe	#
+wsrep_commit_oool	#
+wsrep_commit_window	#
+wsrep_connected	#
 wsrep_desync_count	#
 wsrep_evs_delayed	#
 wsrep_evs_evict_list	#
 wsrep_evs_repl_latency	#
 wsrep_evs_state	#
+wsrep_flow_control_active	#
+wsrep_flow_control_paused	#
+wsrep_flow_control_paused_ns	#
+wsrep_flow_control_recv	#
+wsrep_flow_control_requested	#
+wsrep_flow_control_sent	#
 wsrep_gcomm_uuid	#
 wsrep_gmcast_segment	#
-wsrep_applier_thread_count	#
-wsrep_cluster_capabilities	#
-wsrep_cluster_conf_id	#
-wsrep_cluster_size	#
-wsrep_cluster_state_uuid	#
-wsrep_cluster_status	#
-wsrep_connected	#
+wsrep_incoming_addresses	#
+wsrep_last_committed	#
 wsrep_local_bf_aborts	#
+wsrep_local_cached_downto	#
+wsrep_local_cert_failures	#
+wsrep_local_commits	#
 wsrep_local_index	#
+wsrep_local_recv_queue	#
+wsrep_local_recv_queue_avg	#
+wsrep_local_recv_queue_max	#
+wsrep_local_recv_queue_min	#
+wsrep_local_replays	#
+wsrep_local_send_queue	#
+wsrep_local_send_queue_avg	#
+wsrep_local_send_queue_max	#
+wsrep_local_send_queue_min	#
+wsrep_local_state	#
+wsrep_local_state_comment	#
+wsrep_local_state_uuid	#
+wsrep_open_connections	#
+wsrep_open_transactions	#
+wsrep_protocol_version	#
 wsrep_provider_capabilities	#
 wsrep_provider_name	#
 wsrep_provider_vendor	#
 wsrep_provider_version	#
 wsrep_ready	#
+wsrep_received	#
+wsrep_received_bytes	#
+wsrep_repl_data_bytes	#
+wsrep_repl_keys	#
+wsrep_repl_keys_bytes	#
+wsrep_repl_other_bytes	#
+wsrep_replicated	#
+wsrep_replicated_bytes	#
 wsrep_rollbacker_thread_count	#
 wsrep_thread_count	#
 # Should show nothing.
@@ -89,6 +90,10 @@ SELECT VARIABLE_NAME FROM INFORMATION_SCHEMA.SESSION_VARIABLES WHERE VARIABLE_NA
 VARIABLE_NAME
 WSREP_ALLOWLIST
 WSREP_AUTO_INCREMENT_CONTROL
+WSREP_BUFFERED_ERROR_LOG_BUFFER_SIZE
+WSREP_BUFFERED_ERROR_LOG_FILENAME
+WSREP_BUFFERED_ERROR_LOG_FILE_SIZE
+WSREP_BUFFERED_ERROR_LOG_ROTATIONS
 WSREP_CERTIFICATION_RULES
 WSREP_CERTIFY_NONPK
 WSREP_CLUSTER_ADDRESS
diff --git a/mysql-test/suite/wsrep/r/variables_debug.result b/mysql-test/suite/wsrep/r/variables_debug.result
index 50d695fed4be2..bd04a9c791681 100644
--- a/mysql-test/suite/wsrep/r/variables_debug.result
+++ b/mysql-test/suite/wsrep/r/variables_debug.result
@@ -41,6 +41,7 @@ wsrep_commit_window	#
 wsrep_local_state	#
 wsrep_local_state_comment	#
 wsrep_cert_index_size	#
+wsrep_causal_reads	#
 wsrep_cert_interval	#
 wsrep_open_transactions	#
 wsrep_open_connections	#
@@ -90,6 +91,10 @@ SELECT VARIABLE_NAME FROM INFORMATION_SCHEMA.SESSION_VARIABLES WHERE VARIABLE_NA
 VARIABLE_NAME
 WSREP_ALLOWLIST
 WSREP_AUTO_INCREMENT_CONTROL
+WSREP_BUFFERED_ERROR_LOG_BUFFER_SIZE
+WSREP_BUFFERED_ERROR_LOG_FILENAME
+WSREP_BUFFERED_ERROR_LOG_FILE_SIZE
+WSREP_BUFFERED_ERROR_LOG_ROTATIONS
 WSREP_CERTIFICATION_RULES
 WSREP_CERTIFY_NONPK
 WSREP_CLUSTER_ADDRESS
diff --git a/mysql-test/suite/wsrep/t/variables.test b/mysql-test/suite/wsrep/t/variables.test
index c28638e78f1fb..e4f1658361230 100644
--- a/mysql-test/suite/wsrep/t/variables.test
+++ b/mysql-test/suite/wsrep/t/variables.test
@@ -8,6 +8,7 @@ source include/check_galera_version.inc;
 
 source include/galera_variables_ok.inc;
 
+--sorted_result
 --replace_column 2 #
 SHOW GLOBAL STATUS LIKE 'wsrep%';
 
diff --git a/mysys/CMakeLists.txt b/mysys/CMakeLists.txt
index 1a08bafda99e2..013080cf383f6 100644
--- a/mysys/CMakeLists.txt
+++ b/mysys/CMakeLists.txt
@@ -46,7 +46,7 @@ SET(MYSYS_SOURCES  array.c charset-def.c charset.c my_default.c
                                 my_uuid.c wqueue.c waiting_threads.c ma_dyncol.c ../sql-common/my_time.c
 				my_rdtsc.c psi_noop.c
                                 my_atomic_writes.c my_cpu.c my_likely.c my_largepage.c
-                                file_logger.c my_dlerror.c   crc32/crc32c.cc
+                                file_logger.cc my_dlerror.c   crc32/crc32c.cc
                                 my_timezone.cc  my_thread_name.cc)
 
 IF (WIN32)
diff --git a/mysys/file_logger.cc b/mysys/file_logger.cc
new file mode 100644
index 0000000000000..9a92c50a16cff
--- /dev/null
+++ b/mysys/file_logger.cc
@@ -0,0 +1,454 @@
+/* Copyright (C) 2012-2025 Monty Program Ab
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+
+#ifndef FLOGGER_SKIP_INCLUDES
+#include "my_global.h"
+#include <my_sys.h>
+#include <m_string.h>
+#include <mysql/service_logger.h>
+#include <my_pthread.h>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <sstream>
+#endif /*FLOGGER_SKIP_INCLUDES*/
+
+#ifndef flogger_mutex_init
+#define flogger_mutex_init(A,B,C) mysql_mutex_init(A,B,C)
+#define flogger_mutex_destroy(A) mysql_mutex_destroy(A)
+#define flogger_mutex_lock(A) mysql_mutex_lock(A)
+#define flogger_mutex_unlock(A) mysql_mutex_unlock(A)
+#endif /*flogger_mutex_init*/
+
+#ifdef HAVE_PSI_INTERFACE
+/* These belong to the service initialization */
+static PSI_mutex_key key_LOCK_logger_service;
+static PSI_mutex_info mutex_list[]=
+{{ &key_LOCK_logger_service, "logger_service_file_st::lock", PSI_FLAG_GLOBAL}};
+#endif
+
+struct logger_handle_st
+{
+  logger_handle_st() : data(nullptr), size_limit(0), buffer_limit(0), rotations(0)
+  {}
+  // We are using a pointer to string to guarantee that we can decrease the size
+  // of the buffer
+  // memory buffer storing the log messages
+  std::unique_ptr<std::string> data;
+  unsigned long long size_limit;
+  unsigned long long buffer_limit;
+  unsigned int rotations;
+  File file;
+  char path[FN_REFLEN];
+  size_t path_len;
+  mysql_mutex_t lock;
+
+  void resize_buffer(void);
+};
+
+void logger_handle_st::resize_buffer(void)
+{
+  std::unique_ptr<std::string> new_buffer(new std::string());
+  new_buffer->reserve(buffer_limit);
+  data.swap(new_buffer);
+}
+
+#define LOG_FLAGS (O_APPEND | O_CREAT | O_WRONLY)
+
+static unsigned int n_dig(unsigned int i)
+{
+  unsigned int n=1;
+  if (i < 10)
+    n= 1;
+  else if (i < 100)
+    n= 2;
+  else if (i < 1000)
+    n= 3;
+  else if (i < 10000)
+    n= 4;
+  else if (i < 100000)
+    n= 5;
+  else if (i < 1000000)
+    n= 6;
+  return n;
+}
+
+
+LOGGER_HANDLE *logger_open(const char *path,
+                           unsigned long long size_limit,
+                           unsigned long long buffer_limit,
+                           unsigned int rotations)
+{
+  LOGGER_HANDLE new_log;
+  /*
+    I don't think we ever need more rotations,
+    but if it's so, the rotation procedure should be adapted to it.
+  */
+  if (rotations > 9999999)
+    return 0;
+
+  new_log.path_len= strlen(fn_format(new_log.path, path,
+        mysql_data_home, "", MY_UNPACK_FILENAME));
+
+  if (new_log.path_len+n_dig(rotations)+1 > FN_REFLEN)
+  {
+    errno= ENAMETOOLONG;
+    /* File path too long */
+    return 0;
+  }
+  if ((new_log.file= my_open(new_log.path, LOG_FLAGS, MYF(0))) < 0)
+  {
+    errno= my_errno;
+    /* Check errno for the cause */
+    return 0;
+  }
+
+  struct logger_handle_st* l_handle(new logger_handle_st());
+
+  l_handle->rotations= rotations;
+  l_handle->size_limit= size_limit;
+  l_handle->buffer_limit= buffer_limit;
+  l_handle->path_len= new_log.path_len;
+  strcpy(l_handle->path, new_log.path);
+  l_handle->file= new_log.file;
+
+  flogger_mutex_init(key_LOCK_logger_service, &l_handle->lock,
+                     MY_MUTEX_INIT_FAST);
+
+  if (!buffer_limit)
+    return (LOGGER_HANDLE*)l_handle;
+
+  l_handle->resize_buffer();
+
+  return (LOGGER_HANDLE*)l_handle;
+}
+
+int logger_close(LOGGER_HANDLE *log)
+{
+  int result;
+  File file= log->file;
+  flogger_mutex_destroy(&log->lock);
+  if ((result= my_close(file, MYF(0))))
+    errno= my_errno;
+  delete log;
+  return result;
+}
+
+
+static char *logname(LOGGER_HANDLE *log, char *buf, unsigned int n_log)
+{
+  sprintf(buf+log->path_len, ".%0*u", n_dig(log->rotations), n_log);
+  return buf;
+}
+
+
+static int do_rotate(LOGGER_HANDLE *log)
+{
+  char namebuf[FN_REFLEN];
+  int result;
+  unsigned int i;
+  char *buf_old, *buf_new, *tmp;
+
+  if (log->rotations == 0)
+    return 0;
+
+  memcpy(namebuf, log->path, log->path_len);
+
+  buf_new= logname(log, namebuf, log->rotations);
+  buf_old= log->path;
+  for (i=log->rotations-1; i>0; i--)
+  {
+    logname(log, buf_old, i);
+    if (!access(buf_old, F_OK) &&
+        (result= my_rename(buf_old, buf_new, MYF(0))))
+      goto exit;
+    tmp= buf_old;
+    buf_old= buf_new;
+    buf_new= tmp;
+  }
+  if ((result= my_close(log->file, MYF(0))))
+    goto exit;
+  namebuf[log->path_len]= 0;
+  result= my_rename(namebuf, logname(log, log->path, 1), MYF(0));
+  log->file= my_open(namebuf, LOG_FLAGS, MYF(0));
+exit:
+  errno= my_errno;
+  return log->file < 0 || result;
+}
+
+
+/*
+   Return 1 if we should rotate the log
+*/
+
+my_bool logger_time_to_rotate(LOGGER_HANDLE *log)
+{
+  my_off_t filesize;
+  if (log->rotations > 0)
+  {
+    filesize= my_tell(log->file, MYF(0));
+    if (filesize != (my_off_t) -1)
+    {
+      filesize+= log->data->size(); // Add buffer
+      if ((unsigned long long)filesize >= log->size_limit)
+        return 1;
+    }
+  }
+
+  return 0;
+}
+
+
+int logger_vprintf(LOGGER_HANDLE *log, const char* fmt, va_list ap)
+{
+  int result=0;
+  char cvtbuf[1024];
+  size_t n_bytes;
+
+  flogger_mutex_lock(&log->lock);
+  if (logger_time_to_rotate(log) && do_rotate(log))
+  {
+    result= -1;
+    errno= my_errno;
+    goto exit; /* Log rotation needed but failed */
+  }
+
+  n_bytes= my_vsnprintf(cvtbuf, sizeof(cvtbuf), fmt, ap);
+  if (n_bytes >= sizeof(cvtbuf))
+    n_bytes= sizeof(cvtbuf) - 1;
+
+  if (log->data.get() == nullptr || log->data->capacity() == 0)
+  {
+    result= (int)my_write(log->file, (uchar *) cvtbuf, n_bytes, MYF(0));
+  }
+  else
+  {
+    // Buffered logging
+    const size_t msg_size = log->data->size() + n_bytes;
+    if (msg_size > log->data->capacity() - 1)
+      logger_flush(log);
+    *(log->data)+= cvtbuf;
+  }
+
+exit:
+  flogger_mutex_unlock(&log->lock);
+  return result;
+}
+
+
+static int logger_write_r(LOGGER_HANDLE *log, my_bool allow_rotations,
+                          const char *buffer, size_t size)
+{
+  int result=0;
+
+  flogger_mutex_lock(&log->lock);
+  if (allow_rotations && logger_time_to_rotate(log) && do_rotate(log))
+  {
+    result= -1;
+    errno= my_errno;
+    goto exit; /* Log rotation needed but failed */
+  }
+
+  if (log->data.get() == nullptr || log->data->capacity() == 0)
+  {
+    result= (int)my_write(log->file, (uchar *) buffer, size, MYF(0));
+  }
+  else
+  {
+    // Buffered logging
+    const size_t msg_size = log->data->size() + size;
+    if (msg_size > log->data->capacity() - 1)
+      result= logger_flush(log);
+    *(log->data)+= buffer;
+  }
+
+exit:
+  flogger_mutex_unlock(&log->lock);
+  return result;
+}
+
+
+int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size)
+{
+  return logger_write_r(log, TRUE, buffer, size);
+}
+
+int logger_rotate(LOGGER_HANDLE *log, const unsigned int n_rotations)
+{
+  int result=0;
+  flogger_mutex_lock(&log->lock);
+  if (n_rotations)
+    log->rotations= n_rotations;
+  result= do_rotate(log);
+  flogger_mutex_unlock(&log->lock);
+
+  return result;
+}
+
+
+int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...)
+{
+  int result;
+  va_list args;
+  va_start(args,fmt);
+  result= logger_vprintf(log, fmt, args);
+  va_end(args);
+  return result;
+}
+
+void logger_init_mutexes()
+{
+#ifdef HAVE_PSI_INTERFACE
+  if (unlikely(PSI_server))
+    PSI_server->register_mutex("sql_logger", mutex_list, 1);
+#endif
+}
+
+/** Resize buffer size.
+
+@param[in,out]  log         log handle
+
+@return 0 success, !0 for error  */
+int logger_resize_buffer(LOGGER_HANDLE *log, unsigned long long buffer_limit)
+{
+  if (log->data.get() != nullptr && buffer_limit == log->data->capacity())
+    return 0;
+
+  flogger_mutex_lock(&log->lock);
+  // Write out what we have currently, that way we don't have
+  // to deal with old data in the buffer
+  logger_flush(log);
+  log->buffer_limit= buffer_limit;
+
+  if (buffer_limit == 0)
+  {
+    log->data.reset();
+  }
+  else
+  {
+    log->resize_buffer();
+  }
+
+  flogger_mutex_unlock(&log->lock);
+  return 0;
+}
+
+/** Flush buffered log to the disk.
+
+Note that this function does not use mutexes, thus
+it should be called from function that does or
+in shutdown or from signal handler.
+
+@param[in,out]  log         log handle
+
+@return 0 success, !0 for error  */
+int logger_flush(LOGGER_HANDLE *log)
+{
+  size_t result= 0;
+
+  if (log->data.get() == nullptr || log->data->size() == 0)
+    return 0;
+
+  const size_t curr_size= log->data->capacity();
+  if (logger_time_to_rotate(log) && do_rotate(log))
+  {
+    /* Check errno for the cause */
+    errno= my_errno;
+    result= 1;
+    goto exit;
+  }
+
+  result= my_write(log->file, (uchar *) log->data->data(), log->data->size(), MYF(0));
+
+  if (result == (size_t)-1)
+  {
+    /* Check errno for the cause */
+    errno= my_errno;
+    goto exit;
+  }
+
+  result= 0;
+  log->data->clear();
+  log->data->reserve(curr_size);
+
+exit:
+  return result;
+}
+
+/** Set a new file size limit.
+
+If file size limit is changed we rotate to new log file
+if limit is reached.
+
+@param[in,out]  log         log handle
+@param[in] size_limit       file size limit
+
+@return 0 success, !0 for error  */
+int logger_resize_size(LOGGER_HANDLE *log, unsigned long long size_limit)
+{
+  int ret= 0;
+
+  if (size_limit == log->size_limit)
+    return ret; // nothing to do
+
+  flogger_mutex_lock(&log->lock);
+
+  if ((ret= logger_flush(log)))
+    goto exit;
+
+  log->size_limit= size_limit;
+
+exit:
+  flogger_mutex_unlock(&log->lock);
+  return ret;
+}
+
+
+/** Set a new file name.
+
+@param[in,out]  log         log handle
+@param[in] path             new file name
+
+@return 0 success, !0 for error  */
+int logger_rename_file(LOGGER_HANDLE *log, const char *path)
+{
+  int res=0;
+
+  flogger_mutex_lock(&log->lock);
+
+  if ((res= logger_flush(log)))
+    goto exit;
+
+  if ((res= my_close(log->file, MYF(0))))
+  {
+    /* Check errno for the cause */
+    errno= my_errno;
+    goto exit;
+  }
+
+  log->path_len= strlen(fn_format(log->path, path,
+        mysql_data_home, "", MY_UNPACK_FILENAME));
+
+  if ((log->file= my_open(log->path, LOG_FLAGS, MYF(0))) < 0)
+  {
+    errno= my_errno;
+    /* Check errno for the cause */
+    res= 1;
+  }
+exit:
+  flogger_mutex_unlock(&log->lock);
+  return res;
+}
diff --git a/mysys/file_logger.c b/plugin/server_audit/file_logger.c
similarity index 100%
rename from mysys/file_logger.c
rename to plugin/server_audit/file_logger.c
diff --git a/plugin/server_audit/server_audit.c b/plugin/server_audit/server_audit.c
index be4e0b2294dfa..4b4528c1ce0ad 100644
--- a/plugin/server_audit/server_audit.c
+++ b/plugin/server_audit/server_audit.c
@@ -248,12 +248,14 @@ static my_off_t loc_tell(File fd)
 
 #ifdef HAVE_PSI_INTERFACE
 #undef HAVE_PSI_INTERFACE
-#include <mysql/service_logger.h>
-#include "../../mysys/file_logger.c"
+// Note: as this file is still C, these files are
+// added to this directory to avoid changing this.
+#include "service_logger.h"
+#include "file_logger.c"
 #define HAVE_PSI_INTERFACE
 #else
-#include <mysql/service_logger.h>
-#include "../../mysys/file_logger.c"
+#include "service_logger.h"
+#include "file_logger.c"
 #endif
 #endif /*!MARIADB_ONLY*/
 
diff --git a/plugin/server_audit/service_logger.h b/plugin/server_audit/service_logger.h
new file mode 100644
index 0000000000000..b8d2b1eaf17a1
--- /dev/null
+++ b/plugin/server_audit/service_logger.h
@@ -0,0 +1,105 @@
+/* Copyright (C) 2012 Monty Program Ab
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+#ifndef MYSQL_SERVICE_LOGGER_INCLUDED
+#define MYSQL_SERVICE_LOGGER_INCLUDED
+
+#ifndef MYSQL_ABI_CHECK
+#include <stdarg.h>
+#endif
+
+/**
+  @file
+  logger service
+
+  Log file with rotation implementation.
+
+  This service implements logging with possible rotation
+  of the log files. Interface intentionally tries to be similar to FILE*
+  related functions.
+
+  So that one can open the log with logger_open(), specifying
+  the limit on the logfile size and the rotations number.
+
+  Then it's possible to write messages to the log with
+  logger_printf or logger_vprintf functions.
+
+  As the size of the logfile grows over the specified limit,
+  it is renamed to 'logfile.1'. The former 'logfile.1' becomes
+  'logfile.2', etc. The file 'logfile.rotations' is removed.
+  That's how the rotation works.
+
+  The rotation can be forced with the logger_rotate() call.
+
+  Finally the log should be closed with logger_close().
+
+@notes:
+  Implementation checks the size of the log file before it starts new
+  printf into it. So the size of the file gets over the limit when it rotates.
+
+  The access is secured with the mutex, so the log is threadsafe.
+*/
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct logger_handle_st LOGGER_HANDLE;
+
+extern struct logger_service_st {
+  void (*logger_init_mutexes)();
+  LOGGER_HANDLE* (*open)(const char *path,
+                         unsigned long long size_limit,
+                         unsigned int rotations);
+  int (*close)(LOGGER_HANDLE *log);
+  int (*vprintf)(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
+  int (*printf)(LOGGER_HANDLE *log, const char *fmt, ...);
+  int (*write)(LOGGER_HANDLE *log, const char *buffer, size_t size);
+  int (*rotate)(LOGGER_HANDLE *log);
+} *logger_service;
+
+#ifdef MYSQL_DYNAMIC_PLUGIN
+
+#define logger_init_mutexes logger_service->logger_init_mutexes
+#define logger_open(path, size_limit, rotations) \
+  (logger_service->open(path, size_limit, rotations))
+#define logger_close(log) (logger_service->close(log))
+#define logger_rotate(log) (logger_service->rotate(log))
+#define logger_vprintf(log, fmt, argptr) (logger_service->\
+    vprintf(log, fmt, argptr))
+#define logger_printf (*logger_service->printf)
+#define logger_write(log, buffer, size) \
+  (logger_service->write(log, buffer, size))
+#else
+
+  void logger_init_mutexes();
+  LOGGER_HANDLE *logger_open(const char *path,
+                             unsigned long long size_limit,
+                             unsigned int rotations);
+  int logger_close(LOGGER_HANDLE *log);
+  int logger_vprintf(LOGGER_HANDLE *log, const char *fmt, va_list argptr);
+  int logger_printf(LOGGER_HANDLE *log, const char *fmt, ...);
+  int logger_write(LOGGER_HANDLE *log, const char *buffer, size_t size);
+  int logger_rotate(LOGGER_HANDLE *log);
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*MYSQL_SERVICE_LOGGER_INCLUDED*/
+
diff --git a/plugin/sql_errlog/sql_errlog.c b/plugin/sql_errlog/sql_errlog.c
index 6608bda5cce2a..b865f88511842 100644
--- a/plugin/sql_errlog/sql_errlog.c
+++ b/plugin/sql_errlog/sql_errlog.c
@@ -151,7 +151,7 @@ static int sql_error_log_init(void *p __attribute__((unused)))
 {
   logger_init_mutexes();
 
-  logfile= logger_open(filename, size_limit, rotations);
+  logfile= logger_open(filename, size_limit, 0, rotations);
   if (logfile == NULL) {
     fprintf(stderr, "Could not create file '%s'\n",
             filename);
@@ -175,7 +175,7 @@ static void rotate_log(MYSQL_THD thd  __attribute__((unused)),
                        void *var_ptr  __attribute__((unused)),
                        const void *save  __attribute__((unused)))
 {
-  (void) logger_rotate(logfile);
+  (void) logger_rotate(logfile, 0);
 }
 
 
diff --git a/sql/CMakeLists.txt b/sql/CMakeLists.txt
index 95a83d1244093..e714fd48d15ef 100644
--- a/sql/CMakeLists.txt
+++ b/sql/CMakeLists.txt
@@ -17,6 +17,7 @@
 
 IF(WITH_WSREP AND NOT EMBEDDED_LIBRARY)
   SET(WSREP_SOURCES
+    wsrep_buffered_error_log.cc
     wsrep_client_service.cc
     wsrep_high_priority_service.cc
     wsrep_server_service.cc
diff --git a/sql/handler.cc b/sql/handler.cc
index 570fff8e0edcd..bbe7fc72877bd 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -2343,13 +2343,16 @@ int ha_rollback_trans(THD *thd, bool all)
       transaction_participant *ht= ha_info->ht();
       if ((err= ht->rollback(thd, all)))
       {
-        // cannot happen
         my_error(ER_ERROR_DURING_ROLLBACK, MYF(0), err);
         error=1;
 #ifdef WITH_WSREP
-        WSREP_WARN("handlerton rollback failed, thd %lld %lld conf %d SQL %s",
-                   thd->thread_id, thd->query_id, thd->wsrep_trx().state(),
-                   thd->query());
+	if (WSREP(thd))
+          WSREP_WARN("ht->rollback() failed, thd %lld %lld conf %d "
+                     " err=%s wsrep=%s SQL %s",
+                     thd->thread_id, thd->query_id, thd->wsrep_trx().state(),
+		     strerror(err),
+		     wsrep::to_c_string(thd->wsrep_cs().current_error()),
+                     wsrep_thd_query(thd));
 #endif /* WITH_WSREP */
       }
       status_var_increment(thd->status_var.ha_rollback_count);
@@ -2361,7 +2364,7 @@ int ha_rollback_trans(THD *thd, bool all)
   }
 
 #ifdef WITH_WSREP
-  if (thd->is_error())
+  if (WSREP(thd) && thd->is_error())
   {
     WSREP_DEBUG("ha_rollback_trans(%lld, %s) rolled back: %s: %s; is_real %d",
                 thd->thread_id, all?"TRUE":"FALSE", wsrep_thd_query(thd),
diff --git a/sql/log.cc b/sql/log.cc
index 59168b08f8139..e8129815478ad 100644
--- a/sql/log.cc
+++ b/sql/log.cc
@@ -68,6 +68,7 @@
 #ifdef WITH_WSREP
 #include "wsrep_trans_observer.h"
 #include "wsrep_status.h"
+#include "wsrep_var.h"
 #endif /* WITH_WSREP */
 
 #ifdef HAVE_REPLICATION
@@ -403,11 +404,12 @@ Silence_log_table_errors::handle_condition(THD *,
   return TRUE;
 }
 
-sql_print_message_func sql_print_message_handlers[3] =
+sql_print_message_func sql_print_message_handlers[4] =
 {
   sql_print_information,
   sql_print_warning,
-  sql_print_error
+  sql_print_error,
+  sql_print_debug
 };
 
 
@@ -10024,7 +10026,12 @@ static void print_buffer_to_file(enum loglevel level, const char *buffer,
   struct tm *start;
   THD *thd= 0;
   size_t tag_length= 0;
-  char tag[NAME_LEN];
+  char tag[NAME_LEN] = {'\0'};
+  bool buf_allocated= false;
+  char tmp_buf[MAX_LOG_BUFFER_SIZE]= {'\0'};
+  size_t len= MAX_LOG_BUFFER_SIZE-1;
+  char *buf = &tmp_buf[0];
+
   DBUG_ENTER("print_buffer_to_file");
   DBUG_PRINT("enter",("buffer: %s", buffer));
 
@@ -10049,7 +10056,11 @@ static void print_buffer_to_file(enum loglevel level, const char *buffer,
   localtime_r(&skr, &tm_tmp);
   start=&tm_tmp;
 
-  fprintf_stderr( "%d-%02d-%02d %2d:%02d:%02d %lu [%s] %.*s%.*s\n",
+  assert(level <= DEBUG_LEVEL);
+  const char* level_msg[] =
+    { "ERROR", "Warning", "Note", "Debug" };
+
+  len= snprintf(buf, len, "%d-%02d-%02d %2d:%02d:%02d %lu [%s] %.*s%.*s\n",
           start->tm_year + 1900,
           start->tm_mon+1,
           start->tm_mday,
@@ -10057,14 +10068,51 @@ static void print_buffer_to_file(enum loglevel level, const char *buffer,
           start->tm_min,
           start->tm_sec,
           (unsigned long) (thd ? thd->thread_id : 0),
-          (level == ERROR_LEVEL ? "ERROR" : level == WARNING_LEVEL ?
-           "Warning" : "Note"),
+          level_msg[level],
           (int) tag_length, tag,
           (int) length, buffer);
 
-  fflush(stderr);
+  if (len > sizeof(tmp_buf) -1 )
+  {
+    len += 2; // safety
+    buf= (char *)my_malloc(PSI_INSTRUMENT_ME, len, MYF(MY_WME));
+    buf_allocated= true;
+    len = snprintf(buf, len, "%d-%02d-%02d %2d:%02d:%02d %lu [%s] %.*s%.*s\n",
+            start->tm_year + 1900,
+            start->tm_mon+1,
+            start->tm_mday,
+            start->tm_hour,
+            start->tm_min,
+            start->tm_sec,
+            (unsigned long) (thd ? thd->thread_id : 0),
+            level_msg[level],
+            (int) tag_length, tag,
+            (int) length, buffer);
+  }
 
 #ifdef WITH_WSREP
+  // Use normal logging if log level is not DEBUG OR
+  // if user requested DEBUG level logging and buffered
+  // error log is not on.
+  if (level < DEBUG_LEVEL ||
+      ((wsrep_debug_mode & WSREP_DEBUG_MODE_DEBUG) &&
+       !(wsrep_debug_mode & WSREP_DEBUG_MODE_BUFFERED)))
+  {
+#endif
+    fprintf(stderr, "%s", buf);
+    fflush(stderr);
+#ifdef WITH_WSREP
+  }
+
+  // Use buffred logging if log level is not DEBUG AND
+  // buffered logging is requested OR
+  // if user requested DEBUG level logging and buffered
+  // error log on.
+  if ((level < DEBUG_LEVEL && (wsrep_debug_mode & WSREP_DEBUG_MODE_BUFFERED)) ||
+      ((wsrep_debug_mode & WSREP_DEBUG_MODE_DEBUG) &&
+       (wsrep_debug_mode & WSREP_DEBUG_MODE_BUFFERED)))
+    wsrep_buffered_error_log.log(buf, len);
+
   if (level <= WARNING_LEVEL)
   {
     wsrep::reporter::log_level const lvl = (level <= ERROR_LEVEL ?
@@ -10074,6 +10122,9 @@ static void print_buffer_to_file(enum loglevel level, const char *buffer,
   }
 #endif /* WITH_WSREP */
 
+  if (buf_allocated)
+    my_free(buf);
+
   mysql_mutex_unlock(&LOCK_error_log);
   DBUG_VOID_RETURN;
 }
@@ -10111,6 +10162,17 @@ int vprint_msg_to_log(enum loglevel level, const char *format, va_list args)
 }
 #endif /* EMBEDDED_LIBRARY */
 
+void sql_print_debug(const char *format, ...)
+{
+  va_list args;
+  DBUG_ENTER("sql_print_debug");
+
+  va_start(args, format);
+  error_log_print(DEBUG_LEVEL, format, args);
+  va_end(args);
+
+  DBUG_VOID_RETURN;
+}
 
 void sql_print_error(const char *format, ...) 
 {
diff --git a/sql/log.h b/sql/log.h
index 2f3b6508f58d9..05613b7e6445c 100644
--- a/sql/log.h
+++ b/sql/log.h
@@ -1372,6 +1372,8 @@ void sql_print_error(const char *format, ...);
 void sql_print_warning(const char *format, ...);
 void sql_print_information(const char *format, ...);
 void sql_print_information_v(const char *format, va_list ap);
+void sql_print_debug(const char *format, ...);
+
 typedef void (*sql_print_message_func)(const char *format, ...);
 extern sql_print_message_func sql_print_message_handlers[];
 
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 28f02f7162fdd..3218675229b66 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -1333,9 +1333,10 @@ void Buffered_log::print()
   case WARNING_LEVEL:
     sql_print_warning("Buffered warning: %s", m_message.c_ptr_safe());
     break;
+  case DEBUG_LEVEL:
   case INFORMATION_LEVEL:
     /*
-      Messages printed as "information" still end up in the mysqld *error* log,
+      Messages printed as "information" or "debug" still end up in the mysqld *error* log,
       but with a [Note] tag instead of an [ERROR] tag.
       While this is probably fine for a human reading the log,
       it is upsetting existing automated scripts used to parse logs,
@@ -2065,6 +2066,10 @@ static void clean_up(bool print_message)
   free_error_messages();
   /* Tell main we are ready */
   logger.cleanup_end();
+#ifdef WITH_WSREP
+  wsrep_buffered_error_log.write_to_disk();
+  wsrep_buffered_error_log.close();
+#endif /* WITH_WSREP */
   sys_var_end();
   free_charsets();
 
@@ -5038,6 +5043,13 @@ static int init_server_components()
   error_handler_hook= my_message_sql;
   proc_info_hook= set_thd_stage_info;
 
+#ifdef WITH_WSREP
+  /* Init function will determine if we use buffered error log or not */
+  wsrep_buffered_error_log.init();
+  if (wsrep_debug)
+    wsrep_debug_mode |= WSREP_DEBUG_MODE_DEBUG;
+#endif
+
   /* Set up hook to handle disk full */
   my_sleep_for_space= mariadb_sleep_for_space;
 
diff --git a/sql/signal_handler.cc b/sql/signal_handler.cc
index 96020c68b2bc5..30b09abddb40a 100644
--- a/sql/signal_handler.cc
+++ b/sql/signal_handler.cc
@@ -29,6 +29,10 @@
 #include "wsrep_server_state.h"
 #endif /* WITH_WSREP */
 
+#ifdef WITH_WSREP
+#include "wsrep_mysqld.h"
+#endif
+
 #ifdef _WIN32
 #include <crtdbg.h>
 #include <direct.h>
@@ -147,6 +151,10 @@ extern "C" sig_handler handle_fatal_signal(int sig)
   bool print_invalid_query_pointer= false;
 #endif
 
+#ifdef WITH_WSREP
+  wsrep_buffered_error_log.write_to_disk();
+#endif
+
   if (segfaulted)
   {
     my_safe_printf_stderr("Fatal " SIGNAL_FMT " while backtracing\n", sig);
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 12445dd778231..d12de5cd2dec0 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -1651,7 +1651,8 @@ dispatch_command_return dispatch_command(enum enum_server_command command, THD *
   if (WSREP(thd) && thd->wsrep_next_trx_id() == WSREP_UNDEFINED_TRX_ID)
   {
     thd->set_wsrep_next_trx_id(thd->query_id);
-    WSREP_DEBUG("assigned new next trx id: %" PRIu64, thd->wsrep_next_trx_id());
+    WSREP_DEBUG("Thread %llu assigned new next trx id: %" PRIu64,
+                 thd_get_thread_id(thd),thd->wsrep_next_trx_id());
   }
 #endif /* WITH_WSREP */
 
diff --git a/sql/sql_plugin_services.inl b/sql/sql_plugin_services.inl
index 2114f3560a7ec..dfe1426dc50ae 100644
--- a/sql/sql_plugin_services.inl
+++ b/sql/sql_plugin_services.inl
@@ -114,7 +114,11 @@ static struct logger_service_st logger_service_handler= {
   logger_vprintf,
   logger_printf,
   logger_write,
-  logger_rotate
+  logger_rotate,
+  logger_rename_file,
+  logger_resize_buffer,
+  logger_resize_size,
+  logger_flush
 };
 
 static struct thd_autoinc_service_st thd_autoinc_handler= {
diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index af07c636bc2b6..c09b24d793370 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -69,7 +69,8 @@
 #include <ssl_compat.h>
 #ifdef WITH_WSREP
 #include "wsrep_mysqld.h"
-#endif
+#include "wsrep_buffered_error_log.h"
+#endif /* WITH_WSREP */
 
 #define PCRE2_STATIC 1             /* Important on Windows */
 #include "pcre2.h"                 /* pcre2 header file */
@@ -5224,7 +5225,7 @@ Sys_proxy_protocol_networks(
     ON_CHECK(check_proxy_protocol_networks), ON_UPDATE(fix_proxy_protocol_networks));
 
 
-static bool check_log_path(sys_var *self, THD *thd, set_var *var)
+bool check_log_path(sys_var *self, THD *thd, set_var *var)
 {
   if (!var->value)
     return false; // DEFAULT is ok
@@ -6520,6 +6521,37 @@ static Sys_var_charptr Sys_wsrep_allowlist(
        READ_ONLY GLOBAL_VAR(wsrep_allowlist), CMD_LINE(REQUIRED_ARG),
        DEFAULT(""));
 
+static Sys_var_charptr_fscs Sys_wsrep_buffered_error_log_filename(
+    "wsrep_buffered_error_log_filename", "Filename of the buffered error log",
+    PREALLOCATED GLOBAL_VAR(wsrep_buffered_error_log_filename), CMD_LINE(REQUIRED_ARG),
+    DEFAULT(0), NO_MUTEX_GUARD, NOT_IN_BINLOG,
+    ON_CHECK(wsrep_buffered_error_log_filename_check),
+    ON_UPDATE(wsrep_buffered_error_log_filename_update));
+
+static Sys_var_ulonglong Sys_wsrep_buffered_error_log_buffer_size(
+    "wsrep_buffered_error_log_buffer_size", "Size of the buffered error log buffer",
+    GLOBAL_VAR(wsrep_buffered_error_log_buffer_size), CMD_LINE(REQUIRED_ARG),
+    VALID_RANGE(0, SIZE_T_MAX), DEFAULT(0), BLOCK_SIZE(1), NO_MUTEX_GUARD,
+    NOT_IN_BINLOG,
+    ON_CHECK(wsrep_buffered_error_log_buffer_size_check),
+    ON_UPDATE(wsrep_buffered_error_log_buffer_size_update));
+
+static Sys_var_ulonglong Sys_wsrep_buffered_error_log_file_size(
+    "wsrep_buffered_error_log_file_size", "Max size of the buffered error log file",
+    GLOBAL_VAR(wsrep_buffered_error_log_file_size), CMD_LINE(REQUIRED_ARG),
+    VALID_RANGE(0, SIZE_T_MAX), DEFAULT(0), BLOCK_SIZE(1), NO_MUTEX_GUARD,
+    NOT_IN_BINLOG,
+    ON_CHECK(wsrep_buffered_error_log_file_size_check),
+    ON_UPDATE(wsrep_buffered_error_log_file_size_update));
+
+static Sys_var_uint Sys_wsrep_buffered_error_log_rotations (
+       "wsrep_buffered_error_log_rotations", "Number of log rotations before log is removed",
+       GLOBAL_VAR(wsrep_buffered_error_log_rotations), CMD_LINE(REQUIRED_ARG),
+       VALID_RANGE(0, 999999),
+       DEFAULT(10), BLOCK_SIZE(1), NO_MUTEX_GUARD, NOT_IN_BINLOG,
+       ON_CHECK(wsrep_buffered_error_log_rotations_check),
+       ON_UPDATE(wsrep_buffered_error_log_rotations_update));
+
 #endif /* WITH_WSREP */
 
 static bool fix_host_cache_size(sys_var *, THD *, enum_var_type)
diff --git a/sql/wsrep_buffered_error_log.cc b/sql/wsrep_buffered_error_log.cc
new file mode 100644
index 0000000000000..27345362113b4
--- /dev/null
+++ b/sql/wsrep_buffered_error_log.cc
@@ -0,0 +1,160 @@
+/* Copyright (C) 2025 Codership Oy <info@codership.com>
+
+   Created by Zsolt Parragi <zsolt.parragi@percona.com>
+   Modified by Jan Lindström <jan.lindstrom@galeracluster.com>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation, Inc.,
+   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */
+
+#include "wsrep_buffered_error_log.h"
+#include "wsrep.h"
+#include "wsrep_mysqld.h"
+
+Buffered_error_logger wsrep_buffered_error_log;
+const char *wsrep_buffered_error_log_filename= nullptr;
+unsigned long long wsrep_buffered_error_log_buffer_size= 0;
+unsigned long long wsrep_buffered_error_log_file_size= 0;
+uint wsrep_buffered_error_log_rotations= 0;
+
+void Buffered_error_logger::init()
+{
+  logfile= nullptr;
+
+  if (wsrep_buffered_error_log_buffer_size > 0 &&
+      wsrep_buffered_error_log_file_size > 0 &&
+      wsrep_buffered_error_log_filename != nullptr &&
+      strlen(wsrep_buffered_error_log_filename) > 0)
+  {
+    logfile= logger_open(wsrep_buffered_error_log_filename,
+                         wsrep_buffered_error_log_file_size,
+                         wsrep_buffered_error_log_buffer_size,
+                         wsrep_buffered_error_log_rotations);
+
+    if (!logfile)
+    {
+      WSREP_WARN("Could not open buffered error log %s error=%s (%d).",
+                 wsrep_buffered_error_log_filename,
+                 strerror(errno), errno);
+      wsrep_disable_logging();
+    }
+    else
+    {
+      wsrep_debug_mode |= WSREP_DEBUG_MODE_BUFFERED;
+    }
+  }
+
+  return;
+}
+
+void Buffered_error_logger::resize_buffer(const std::size_t buffer_size)
+{
+  if (!logfile)
+    return;
+
+  if (logger_resize_buffer(logfile, buffer_size))
+  {
+    wsrep_disable_logging();
+    WSREP_WARN("Resize of buffered error log %s to size %zd failed error=%s (%ld).",
+               wsrep_buffered_error_log_filename, buffer_size,
+               strerror(errno), errno);
+  }
+}
+
+void Buffered_error_logger::resize_file_size(const std::size_t file_size)
+{
+  if (!logfile)
+    return;
+
+  if (logger_resize_size(logfile, file_size))
+  {
+    wsrep_disable_logging();
+    WSREP_WARN("Resize of buffered error log %s file size to %zd failed error=%s (%ld).",
+               wsrep_buffered_error_log_filename, file_size,
+               strerror(errno), errno);
+  }
+}
+
+void Buffered_error_logger::rename_file(const char* new_name)
+{
+  if (!logfile)
+    return;
+
+  if (logger_rename_file(logfile, new_name))
+  {
+    wsrep_disable_logging();
+    WSREP_WARN("Rename of buffered error log %s to %s failed error=%s (%ld).",
+               wsrep_buffered_error_log_filename, new_name,
+               strerror(errno), errno);
+  }
+}
+
+Buffered_error_logger::~Buffered_error_logger()
+{
+  if (logfile)
+  {
+    logger_close(logfile);
+    logfile= nullptr;
+  }
+}
+
+void Buffered_error_logger::log(const char *msg, const std::size_t len)
+{
+  if (logfile)
+  {
+    if (logger_write(logfile, msg, len))
+    {
+      wsrep_disable_logging();
+      WSREP_WARN("Log write to buffered error log %s failed error=%s (%ld).",
+               wsrep_buffered_error_log_filename,
+               strerror(errno), errno);
+    }
+  }
+}
+
+void Buffered_error_logger::write_to_disk()
+{
+  if (logfile)
+  {
+    if (logger_flush(logfile))
+    {
+      wsrep_disable_logging();
+      WSREP_WARN("Log write to buffered error log %s failed error=%s (%ld).",
+               wsrep_buffered_error_log_filename,
+               strerror(errno), errno);
+    }
+  }
+}
+
+void Buffered_error_logger::close()
+{
+  if (logfile)
+  {
+    logger_flush(logfile);
+    logger_close(logfile);
+    logfile= nullptr;
+  }
+}
+
+void Buffered_error_logger::rotate(const uint n_rotations)
+{
+  if (!logfile || n_rotations == 0)
+    return;
+
+  if (logger_rotate(logfile, n_rotations))
+  {
+    wsrep_disable_logging();
+    WSREP_WARN("Rotation of buffered error log %s failed error=%s (%ld).",
+               wsrep_buffered_error_log_filename,
+               strerror(errno), errno);
+  }
+}
diff --git a/sql/wsrep_buffered_error_log.h b/sql/wsrep_buffered_error_log.h
new file mode 100644
index 0000000000000..9735282cb45df
--- /dev/null
+++ b/sql/wsrep_buffered_error_log.h
@@ -0,0 +1,56 @@
+/* Copyright (C) 2025 Codership Oy <info@codership.com>
+
+   Created by Zsolt Parragi <zsolt.parragi@percona.com>
+   Modified by Jan Lindström <jan.lindstrom@galeracluster.com>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this program; if not, write to the Free Software Foundation, Inc.,
+   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */
+#ifndef WSREP_BUFFERED_ERROR_LOG_H
+#define WSREP_BUFFERED_ERROR_LOG_H 1
+
+#include <stdio.h>
+#include <cstring>
+#include <memory>
+#include <mutex>
+#include <vector>
+#include <cstdio>
+#include <string>
+#include <mysql/service_logger.h>
+
+/** Stores log messages in a fixed size buffer, which can be dumped by large
+ * chunks instead of line by line, to increase performance for high throughput
+ * scenarios.
+ *
+ * The buffer is also dumped by the crash reporting code and during shutdown to
+ * ensure that nothing is lost, only delayed.
+ */
+class Buffered_error_logger
+{
+private:
+  LOGGER_HANDLE* logfile;
+
+ public:
+  void init();
+  void resize_buffer(const std::size_t buffer_size);
+  void resize_file_size(const std::size_t file_size);
+  void rename_file(const char* new_name);
+  void rotate(const uint n_rotations);
+
+  ~Buffered_error_logger();
+
+  void log(const char *msg, const std::size_t len);
+  void write_to_disk();
+  void close();
+};
+
+#endif /* WSREP_BUFFERED_ERROR_LOG */
diff --git a/sql/wsrep_mysqld.cc b/sql/wsrep_mysqld.cc
index cf8b9d36c9120..e759d54d5623c 100644
--- a/sql/wsrep_mysqld.cc
+++ b/sql/wsrep_mysqld.cc
@@ -1,5 +1,5 @@
-/* Copyright (c) 2008, 2023 Codership Oy <http://www.codership.com>
-   Copyright (c) 2020, 2022, MariaDB
+/* Copyright (c) 2008, 2025 Codership Oy <http://www.codership.com>
+   Copyright (c) 2020, 2024, MariaDB
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -130,6 +130,8 @@ uint  wsrep_ignore_apply_errors= 0;
 
 std::atomic <bool> wsrep_thread_create_failed;
 
+ulong wsrep_debug_mode= 0;
+
 /*
  * End configuration options
  */
@@ -4041,3 +4043,14 @@ void wsrep_commit_empty(THD* thd, bool all)
   }
   DBUG_VOID_RETURN;
 }
+
+void wsrep_disable_logging(void)
+{
+  // Disable buffered error logging
+  wsrep_debug_mode &= ~WSREP_DEBUG_MODE_BUFFERED;
+  // Disable also wsrep_debug logging
+  wsrep_debug_mode &= WSREP_DEBUG_MODE_DEBUG;
+  // Set wsrep_debug to NONE
+  wsrep_debug=0;
+  WSREP_WARN("Buffered error logging and wsrep debug logging disabled.");
+}
diff --git a/sql/wsrep_mysqld.h b/sql/wsrep_mysqld.h
index 183dc65b00707..204d42a0e301d 100644
--- a/sql/wsrep_mysqld.h
+++ b/sql/wsrep_mysqld.h
@@ -1,4 +1,4 @@
-/* Copyright 2008-2023 Codership Oy <http://www.codership.com>
+/* Copyright 2008-2024 Codership Oy <http://www.codership.com>
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -38,6 +38,7 @@ typedef struct st_mysql_show_var SHOW_VAR;
 #include "wsrep/streaming_context.hpp"
 #include "wsrep_api.h"
 #include <map>
+#include "wsrep_buffered_error_log.h"
 
 #define WSREP_UNDEFINED_TRX_ID ULONGLONG_MAX
 
@@ -145,6 +146,13 @@ enum enum_wsrep_mode {
 extern const char *wsrep_fragment_units[];
 extern const char *wsrep_SR_store_types[];
 
+/* Modes for wsrep debug error logging */
+enum enum_wsrep_debug_mode {
+  WSREP_DEBUG_MODE_OFF = 0x0,
+  WSREP_DEBUG_MODE_DEBUG = 0x1,
+  WSREP_DEBUG_MODE_BUFFERED = 0x2
+};
+
 // MySQL status variables
 extern my_bool     wsrep_connected;
 extern const char* wsrep_cluster_state_uuid;
@@ -158,6 +166,11 @@ extern const char* wsrep_provider_version;
 extern const char* wsrep_provider_vendor;
 extern char*       wsrep_provider_capabilities;
 extern char*       wsrep_cluster_capabilities;
+extern unsigned long long   wsrep_buffered_error_log_buffer_size;
+extern unsigned long long   wsrep_buffered_error_log_file_size;
+extern const char* wsrep_buffered_error_log_filename;
+extern Buffered_error_logger wsrep_buffered_error_log;
+extern uint        wsrep_buffered_error_log_rotations;
 
 int  wsrep_show_status(THD *thd, SHOW_VAR *var, void *buff,
                        system_status_var *status_var, enum_var_type scope);
@@ -593,6 +606,9 @@ wsrep::key wsrep_prepare_key_for_toi(const char* db, const char* table,
 
 void wsrep_wait_ready(THD *thd);
 void wsrep_ready_set(bool ready_value);
+
+void wsrep_disable_logging(void);
+
 #else /* !WITH_WSREP */
 
 /* These macros are needed to compile MariaDB without WSREP support
diff --git a/sql/wsrep_trans_observer.h b/sql/wsrep_trans_observer.h
index 25e71638efd74..1e216803b9fd6 100644
--- a/sql/wsrep_trans_observer.h
+++ b/sql/wsrep_trans_observer.h
@@ -472,12 +472,6 @@ static inline
 int wsrep_after_statement(THD* thd)
 {
   DBUG_ENTER("wsrep_after_statement");
-  WSREP_DEBUG("wsrep_after_statement for %lu client_state %s "
-              " client_mode %s trans_state %s",
-              thd_get_thread_id(thd),
-              wsrep::to_c_string(thd->wsrep_cs().state()),
-              wsrep::to_c_string(thd->wsrep_cs().mode()),
-              wsrep::to_c_string(thd->wsrep_cs().transaction().state()));
   int ret= ((thd->wsrep_cs().state() != wsrep::client_state::s_none &&
                thd->wsrep_cs().mode() == Wsrep_client_state::m_local) &&
               !thd->internal_transaction() ?
diff --git a/sql/wsrep_var.cc b/sql/wsrep_var.cc
index 83e017a2fc312..03b47476c72fd 100644
--- a/sql/wsrep_var.cc
+++ b/sql/wsrep_var.cc
@@ -1,4 +1,4 @@
-/* Copyright 2008-2022 Codership Oy <http://www.codership.com>
+/* Copyright 2008-2025 Codership Oy <http://www.codership.com>
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -596,6 +596,11 @@ bool wsrep_debug_update(sys_var *self, THD* thd, enum_var_type type)
   else
     Wsrep_server_state::instance().debug_log_level(wsrep_debug);
 
+  if (wsrep_debug)
+    wsrep_debug_mode |= WSREP_DEBUG_MODE_DEBUG;
+  else
+    wsrep_debug_mode &= ~WSREP_DEBUG_MODE_DEBUG;
+
   return false;
 }
 
@@ -1121,3 +1126,173 @@ bool wsrep_gtid_domain_id_update(sys_var* self, THD *thd, enum_var_type)
   return false;
 }
 
+bool wsrep_buffered_error_log_buffer_size_update(sys_var *, THD *, enum_var_type)
+{
+  wsrep_buffered_error_log.resize_buffer(wsrep_buffered_error_log_buffer_size);
+
+  if (wsrep_buffered_error_log_buffer_size)
+    wsrep_debug_mode |= WSREP_DEBUG_MODE_BUFFERED;
+  else
+    wsrep_debug_mode &= ~WSREP_DEBUG_MODE_BUFFERED;
+
+  return false;
+}
+
+bool wsrep_buffered_error_log_buffer_size_check(sys_var *self, THD* thd, set_var *var)
+{
+  const unsigned long long new_buffer_size= var->save_result.ulonglong_value;
+
+  if (!new_buffer_size)
+    return false;
+
+  if (!WSREP(thd))
+  {
+    push_warning (thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Cannot set 'wsrep_buffered_error_log_size' to a value other than "
+                  "0 because wsrep is switched off.");
+    return true;
+  }
+
+  const unsigned long long max_size= wsrep_buffered_error_log_file_size / 10;
+  const unsigned long long min_size= wsrep_debug ? 100 * 1024 : 10 * 1024;
+
+  if (new_buffer_size < min_size || new_buffer_size > max_size)
+  {
+    push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Parameter 'wsrep_buffered_error_log_size' should be at range"
+                  " %llu-%llu because wsrep_buffered_error_log_file_size=%llu",
+                  min_size, max_size,
+                  wsrep_buffered_error_log_file_size);
+    return true;
+  }
+
+  return false;
+}
+
+bool wsrep_buffered_error_log_file_size_update(sys_var *, THD *, enum_var_type)
+{
+  wsrep_buffered_error_log.resize_file_size(wsrep_buffered_error_log_file_size);
+  return false;
+}
+
+bool wsrep_buffered_error_log_file_size_check(sys_var *self, THD* thd, set_var *var)
+{
+  const unsigned long long new_file_size= var->save_result.ulonglong_value;
+
+  if (!new_file_size)
+    return false;
+
+  if (!WSREP(thd))
+  {
+    push_warning (thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Cannot set 'wsrep_buffered_error_log_file_size' to a value other than "
+                  "0 because wsrep is switched off.");
+    return true;
+  }
+
+  if (!wsrep_buffered_error_log_buffer_size)
+  {
+    push_warning (thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Cannot set 'wsrep_buffered_error_log_file_size' to a value other than "
+                  "0 because wsrep_buffered_error_log_buffer_size is 0.");
+    return true;
+  }
+
+  if (new_file_size < wsrep_buffered_error_log_buffer_size * 10)
+  {
+    push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Cannot set 'wsrep_buffered_error_log_file_size' too small "
+                  "should be at least %llu.", wsrep_buffered_error_log_buffer_size * 10);
+    return true;
+  }
+
+  return false;
+}
+
+extern bool check_log_path(sys_var *self, THD *thd, set_var *var); // sys_var.cc
+
+bool wsrep_buffered_error_log_filename_update(sys_var*, THD* thd, enum_var_type type)
+{
+  // empty
+  if (!wsrep_buffered_error_log_filename ||
+      strlen(wsrep_buffered_error_log_filename) == 0)
+    return false;
+
+  wsrep_buffered_error_log.rename_file(wsrep_buffered_error_log_filename);
+  return false;
+}
+
+bool wsrep_buffered_error_log_filename_check(sys_var *self, THD* thd, set_var *var)
+{
+  // Allow empty
+  if (!var->value ||
+      !var->save_result.string_value.str ||
+      strlen(var->save_result.string_value.str) == 0)
+    return false;
+
+  if (!WSREP(thd))
+  {
+    push_warning (thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Cannot set 'wsrep_buffered_error_log_filename' "
+                  "because wsrep is switched off.");
+    return true;
+  }
+
+  if (!wsrep_buffered_error_log_buffer_size || !wsrep_buffered_error_log_file_size)
+  {
+    push_warning (thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Cannot set 'wsrep_buffered_error_log_filename' "
+                  "because wsrep_buffered_error_log_buffer_size or"
+                  "wsrep_buffered_error_log_file_size is 0.");
+    return true;
+  }
+
+  if (check_log_path(self, thd, var))
+  {
+    push_warning_printf (thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Cannot set 'wsrep_buffered_error_log_filename' to %s",
+                  var->save_result.string_value.str);
+    return true;
+  }
+
+  return false;
+}
+
+bool wsrep_buffered_error_log_rotations_update(sys_var *, THD *, enum_var_type)
+{
+  wsrep_buffered_error_log.rotate(wsrep_buffered_error_log_rotations);
+  return false;
+}
+
+bool wsrep_buffered_error_log_rotations_check(sys_var *self, THD* thd, set_var *var)
+{
+  const longlong new_rotations= (longlong)var->save_result.ulonglong_value;
+
+  if (!WSREP(thd) && new_rotations)
+  {
+    push_warning (thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Cannot set 'wsrep_buffered_error_log_rotations' to a value other than "
+                  "0 because wsrep is switched off.");
+    return true;
+  }
+
+  if (!wsrep_buffered_error_log_buffer_size && new_rotations)
+  {
+    push_warning (thd, Sql_condition::WARN_LEVEL_WARN,
+                  ER_WRONG_VALUE_FOR_VAR,
+                  "Cannot set 'wsrep_buffered_error_log_rotations' to a value other than "
+                  "0 because wsrep_buffered_error_log_buffer_size is 0.");
+    return true;
+  }
+
+  return false;
+}
diff --git a/sql/wsrep_var.h b/sql/wsrep_var.h
index 6b10530ae97ce..182812728c949 100644
--- a/sql/wsrep_var.h
+++ b/sql/wsrep_var.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2013-2022 Codership Oy <info@codership.com>
+/* Copyright (C) 2013-2025 Codership Oy <info@codership.com>
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -109,6 +109,15 @@ extern bool wsrep_gtid_seq_no_check          CHECK_ARGS;
 extern bool wsrep_gtid_domain_id_update      UPDATE_ARGS;
 
 extern bool wsrep_mode_check                 CHECK_ARGS;
+
+extern bool wsrep_buffered_error_log_buffer_size_update  UPDATE_ARGS;
+extern bool wsrep_buffered_error_log_buffer_size_check   CHECK_ARGS;
+extern bool wsrep_buffered_error_log_file_size_update    UPDATE_ARGS;
+extern bool wsrep_buffered_error_log_file_size_check     CHECK_ARGS;
+extern bool wsrep_buffered_error_log_filename_check      CHECK_ARGS;
+extern bool wsrep_buffered_error_log_filename_update     UPDATE_ARGS;
+extern bool wsrep_buffered_error_log_rotations_update    UPDATE_ARGS;
+extern bool wsrep_buffered_error_log_rotations_check     CHECK_ARGS;
 #else  /* WITH_WSREP */
 
 #define wsrep_provider_init(X)