Improve metadata bwc test - FDW

Author: jeeminso

tests/bwc/test_rolling_upgrade.py

@@ -88,6 +88,10 @@ def _test_rolling_upgrade(self, path, nodes):
         }
         cluster = self._new_cluster(path.from_version, nodes, settings=settings)
         cluster.start()
+        replica_cluster = None
+        if path.from_version.startswith("5"):
+            replica_cluster = self._new_cluster(path.from_version, 1, settings=settings, explicit_discovery=False)
+            replica_cluster.start()
         with connect(cluster.node().http_url, error_trace=True) as conn:
             c = conn.cursor()
             c.execute("create user arthur with (password = 'secret')")
@@ -133,6 +137,21 @@ def _test_rolling_upgrade(self, path, nodes):
                     ) partitioned by (a) clustered into 1 shards with (number_of_replicas = 0)
                 ''')
 
+                # FDW: two CrateDB clusters setting up foreign data wrappers bidirectionally
+                if int(path.from_version.split('.')[1]) >= 7:
+                    c.execute("create table doc.y (a int) clustered into 1 shards with (number_of_replicas=0)")
+                    expected_active_shards += 1
+                    with connect(replica_cluster.node().http_url, error_trace=True) as replica_conn:
+                        rc = replica_conn.cursor()
+                        psql_port = cluster.node().addresses.psql.port
+                        replica_psql_port = replica_cluster.node().addresses.psql.port
+                        assert 5430 <= psql_port <= 5440 and 5430 <= replica_psql_port <= 5440
+                        rc.execute("create table doc.y (a int) clustered into 1 shards with (number_of_replicas=0)")
+                        rc.execute(f"CREATE SERVER source FOREIGN DATA WRAPPER jdbc OPTIONS (url 'jdbc:postgresql://localhost:{psql_port}/')")
+                        rc.execute("CREATE FOREIGN TABLE doc.remote_y (a int) SERVER source OPTIONS (schema_name 'doc', table_name 'y')")
+                    c.execute(f"CREATE SERVER remote FOREIGN DATA WRAPPER jdbc OPTIONS (url 'jdbc:postgresql://localhost:{replica_psql_port}/')")
+                    c.execute("CREATE FOREIGN TABLE doc.remote_y (a int) SERVER remote OPTIONS (schema_name 'doc', table_name 'y')")
+
             c.execute('''
                 CREATE FUNCTION foo(INT)
                 RETURNS INT
@@ -282,6 +301,26 @@ def _test_rolling_upgrade(self, path, nodes):
                         c.execute("select version['created'] from information_schema.table_partitions where table_name = 't3' and values['a'] = ?", [idx])
                         self.assertEqual(c.fetchall(), [[partition_version]])
 
+                    # Ensure FDWs are functional
+                    if int(path.from_version.split('.')[1]) >= 7:
+                        with connect(replica_cluster.node().http_url, error_trace=True) as replica_conn:
+                            rc = replica_conn.cursor()
+                            wait_for_active_shards(c)
+                            wait_for_active_shards(rc)
+                            rc.execute("select count(a) from doc.remote_y")
+                            count = rc.fetchall()[0][0]
+                            c.execute("insert into doc.y values (1)")
+                            c.execute("refresh table doc.y")
+                            rc.execute("select count(a) from doc.remote_y")
+                            self.assertEqual(rc.fetchall()[0][0], count + 1)
+
+                            c.execute("select count(a) from doc.remote_y")
+                            count = c.fetchall()[0][0]
+                            rc.execute("insert into doc.y values (1)")
+                            rc.execute("refresh table doc.y")
+                            c.execute("select count(a) from doc.remote_y")
+                            self.assertEqual(c.fetchall()[0][0], count + 1)
+
         # Finally validate that all shards (primaries and replicas) of all partitions are started
         # and writes into the partitioned table while upgrading were successful
         with connect(cluster.node().http_url, error_trace=True) as conn: