diff --git a/text/0097-log-data-model.md b/text/0097-log-data-model.md new file mode 100644 index 000000000..e01fa8b1e --- /dev/null +++ b/text/0097-log-data-model.md @@ -0,0 +1,1348 @@ +# Log Data Model + +Introduce Data Model for Log Records as it is understood by OpenTelemetry. + +* [Motivation](#motivation) +* [Design Notes](#design-notes) + * [Requirements](#requirements) + * [Field Kinds](#field-kinds) +* [Log and Event Record Definition](#log-and-event-record-definition) + * [Field: `Timestamp`](#field-timestamp) + * [Trace Context Fields](#trace-context-fields) + * [Field: `TraceId`](#field-traceid) + * [Field: `SpanId`](#field-spanid) + * [Field: `TraceFlags`](#field-traceflags) + * [Severity Fields](#severity-fields) + * [Field: `SeverityText`](#field-severitytext) + * [Field: `SeverityNumber`](#field-severitynumber) + * [Mapping of `SeverityNumber`](#mapping-of-severitynumber) + * [Reverse Mapping](#reverse-mapping) + * [Error Semantics](#error-semantics) + * [Displaying Severity](#displaying-severity) + * [Comparing Severity](#comparing-severity) + * [Field: `ShortName`](#field-shortname) + * [Field: `Body`](#field-body) + * [Field: `Resource`](#field-resource) + * [Field: `Attributes`](#field-attributes) +* [Example Log Records](#example-log-records) +* [Open Questions](#open-questions) +* [Alternate Design](#alternate-design) +* [Prior Art](#prior-art) + * [RFC5424 Syslog](#rfc5424-syslog) + * [Fluentd Forward Protocol Model](#fluentd-forward-protocol-model) +* [Appendix A. Example Mappings](#appendix-a-example-mappings) + * [RFC5424 Syslog](#rfc5424-syslog-1) + * [Windows Event Log](#windows-event-log) + * [SignalFx Events](#signalfx-events) + * [Splunk HEC](#splunk-hec) + * [Log4j](#log4j) + * [Zap](#zap) + * [Apache HTTP Server access log](#apache-http-server-access-log) + * [CloudTrail Log Event](#cloudtrail-log-event) + * [Google Cloud Logging](#google-cloud-logging) +* [Appendix B: `SeverityNumber` example mappings](#appendix-b-severitynumber-example-mappings) +* [References](#references) + +## Motivation + +This is a proposal of a data model and semantic conventions that allow to +represent logs from various sources: application log files, machine generated +events, system logs, etc. Existing log formats can be unambiguously mapped to +this data model. Reverse mapping from this data model is also possible to the +extent that the target log format has equivalent capabilities. + +The purpose of the data model is to have a common understanding of what a log +record is, what data needs to be recorded, transferred, stored and interpreted +by a logging system. + +This proposal defines a data model for [Standalone +Logs](https://github.com/open-telemetry/oteps/blob/master/text/logs/0091-logs-vocabulary.md#standalone-log). +Relevant parts of it may be adopted for +[Embedded Logs](https://github.com/open-telemetry/oteps/blob/master/text/logs/0091-logs-vocabulary.md#embedded-log) +in a future OTEP. + +## Design Notes + +### Requirements + +The Data Model was designed to satisfy the following requirements: + +- It should be possible to unambiguously map existing log formats to this Data + Model. Translating log data from an arbitrary log format to this Data Model + and back should ideally result in identical data. + +- Mappings of other log formats to this Data Model should be semantically + meaningful. The Data Model must preserve the semantics of particular elements + of existing log formats. + +- Translating log data from an arbitrary log format A to this Data Model and + then translating from the Data Model to another log format B ideally must + result in a meaningful translation of log data that is no worse than a + reasonable direct translation from log format A to log format B. + +- It should be possible to efficiently represent the Data Model in concrete + implementations that require the data to be stored or transmitted. We + primarily care about 2 aspects of efficiency: CPU usage for + serialization/deserialization and space requirements in serialized form. This + is an indirect requirement that is affected by the specific representation of + the Data Model rather than the Data Model itself, but is still useful to keep + in mind. + +The Data Model aims to successfully represent 3 sorts of logs and events: + +- System Formats. These are logs and events generated by the operating system + and over which we have no control - we cannot change the format or affect what + information is included (unless the data is generated by an application which + we can modify). An example of system format is Syslog. + +- Third-party Applications. These are generated by third-party applications. We + may have certain control over what information is included, e.g. customize the + format. An example is Apache log file. + +- First-party Applications. These are applications that we develop and we have + some control over how the logs and events are generated and what information + we include in the logs. We can likely modify the source code of the + application if needed. + +### Field Kinds + +This Data Model defines a logical model for a log record (irrespective of the +physical format and encoding of the record). Each record contains 2 kinds of +fields: + +- Named top-level fields of specific type and meaning. + +- Fields stored in the key/value pair lists, which can contain arbitrary values + of different types. The keys and values for well-known fields follow semantic + conventions for key names and possible values that allow all parties that work + with the field to have the same interpretation of the data. See references to + semantic conventions for `Resource` and `Attributes` fields and examples in + [Appendix A](#appendix-a-example-mappings). + +The reasons for having these 2 kinds of fields are: + +- Ability to efficiently represent named top-level fields, which are almost + always present (e.g. when using encodings like Protocol Buffers where fields + are enumerated but not named on the wire). + +- Ability to enforce types of named fields, which is very useful for compiled + languages with type checks. + +- Flexibility to represent less frequent data via key/value pair lists. This + includes well-known data that has standardized semantics as well as arbitrary + custom data that the application may want to include in the logs. + +When designing this data model we followed the following reasoning to make a +decision about when to use a top-level named field: + +- The field needs to be either mandatory for all records or be frequently + present in well-known log and event formats (such as `Timestamp`) or is + expected to be often present in log records in upcoming logging systems (such + as `TraceId`). + +- The field’s semantics must be the same for all known log and event formats and + can be mapped directly and unambiguously to this data model. + +Both of the above conditions were required to give the field a place in the +top-level structure of the record. + +## Log and Event Record Definition + +Note: below we use type `any`, which can be a scalar value (number, string or +boolean), or an array or map of values. Arbitrary deep nesting of values for +arrays and maps is allowed (essentially allow to represent an equivalent of a +JSON object). + +[Appendix A](#appendix-a-example-mappings) contains many examples that show how +existing log formats map to the fields defined below. If there are questions +about the meaning of the field reviewing the examples may be helpful. + +Here is the list of fields in a log record: + +Field Name |Description +---------------|-------------------------------------------- +Timestamp |Time when the event occurred. +TraceId |Request trace id. +SpanId |Request span id. +TraceFlags |W3C trace flag. +SeverityText |The severity text (also known as log level). +SeverityNumber |Numerical value of the severity. +ShortName |Short event identifier. +Body |The body of the log record. +Resource |Describes the source of the log. +Attributes |Additional information about the event. + +Below is the detailed description of each field. + +### Field: `Timestamp` + +Type: Timestamp, uint64 nanoseconds since Unix epoch. + +Description: Time when the event occurred measured by the origin clock. This +field is optional, it may be missing if the timestamp is unknown. + +### Trace Context Fields + +#### Field: `TraceId` + +Type: byte sequence. + +Description: Request trace id as defined in +[W3C Trace Context](https://www.w3.org/TR/trace-context/#trace-id). Can be set +for logs that are part of request processing and have an assigned trace id. This +field is optional. + +#### Field: `SpanId` + +Type: byte sequence. + +Description: Span id. Can be set for logs that are part of a particular +processing span. If SpanId is present TraceId SHOULD be also present. This field +is optional. + +#### Field: `TraceFlags` + +Type: byte. + +Description: Trace flag as defined in +[W3C Trace Context](https://www.w3.org/TR/trace-context/#trace-flags) +specification. At the time of writing the specification defines one flag - the +SAMPLED flag. This field is optional. + +### Severity Fields + +#### Field: `SeverityText` + +Type: string. + +Description: severity text (also known as log level). This is the original +string representation of the severity as it is known at the source. If this +field is missing and `SeverityNumber` is present then the short name that +corresponds to the `SeverityNumber` may be used as a substitution. This field is +optional. + +#### Field: `SeverityNumber` + +Type: number. + +Description: numerical value of the severity, normalized to values described in +this document. This field is optional. + +`SeverityNumber` is an integer number. Smaller numerical values correspond to +less severe events (such as debug events), larger numerical values correspond to +more severe events (such as errors and critical events). The following table +defines the meaning of `SeverityNumber` value: + +SeverityNumber range|Range name|Meaning +--------------------|----------|------- +1-4 |TRACE |A fine-grained debugging event. Typically disabled in default configurations. +5-8 |DEBUG |A debugging event. +9-12 |INFO |An informational event. Indicates that an event happened. +13-16 |WARN |A warning event. Not an error but is likely more important than an informational event. +17-20 |ERROR |An error event. Something went wrong. +21-24 |FATAL |A fatal error such as application or system crash. + +Smaller numerical values in each range represent less important (less severe) +events. Larger numerical values in each range represent more important (more +severe) events. For example `SeverityNumber=17` describes an error that is less +critical than an error with `SeverityNumber=20`. + +#### Mapping of `SeverityNumber` + +Mappings from existing logging systems and formats (or **source format** for +short) must define how severity (or log level) of that particular format +corresponds to `SeverityNumber` of this data model based on the meaning given +for each range in the above table. + +If the source format has more than one severity that matches a single range in +this table then the severities of the source format must be assigned numerical +values from that range according to how severe (important) the source severity +is. + +For example if the source format defines "Error" and "Critical" as error events +and "Critical" is a more important and more severe situation then we can choose +the following `SeverityNumber` values for the mapping: "Error"->17, +"Critical"->18. + +If the source format has only a single severity that matches the meaning of the +range then it is recommended to assign that severity the smallest value of the +range. + +For example if the source format has an "Informational" log level and no other +log levels with similar meaning then it is recommended to use +`SeverityNumber=9` for "Informational". + +Source formats that do not define a concept of severity or log level MAY omit +`SeverityNumber` and `SeverityText` fields. Backend and UI may represent log +records with missing severity information distinctly or may interpret log +records with missing `SeverityNumber` and `SeverityText` fields as if the +`SeverityNumber` was set equal to INFO (numeric value of 9). + +#### Reverse Mapping + +When performing a reverse mapping from `SeverityNumber` to a specific format +and the `SeverityNumber` has no corresponding mapping entry for that format +then it is recommended to choose the target severity that is in the same +severity range and is closest numerically. + +For example Zap has only one severity in the INFO range, called "Info". When +doing reverse mapping all `SeverityNumber` values in INFO range (numeric 9-12) +will be mapped to Zap’s "Info" level. + +#### Error Semantics + +If `SeverityNumber` is present and has a value of ERROR (numeric 17) or higher +then it is an indication that the log record represents an erroneous situation. +It is up to the reader of this value to make a decision on how to use this fact +(e.g. UIs may display such errors in a different color or have a feature to find +all erroneous log records). + +If the log record represents an erroneous event and the source format does not +define a severity or log level concept then it is recommended to set +`SeverityNumber` to ERROR (numeric 17) during the mapping process. If the log +record represents a non-erroneous event the `SeverityNumber` field may be +omitted or may be set to any numeric value less than ERROR (numeric 17). The +recommended value in this case is INFO (numeric 9). See +[Appendix B](#appendix-b-severitynumber-example-mappings) for more mapping +examples. + +#### Displaying Severity + +The following table defines the recommended short name for each +`SeverityNumber` value. The short name can be used for example for representing +the `SeverityNumber` in the UI: + +SeverityNumber|Short Name +--------------|---------- +1 |TRACE +2 |TRACE2 +3 |TRACE3 +4 |TRACE4 +5 |DEBUG +6 |DEBUG2 +7 |DEBUG3 +8 |DEBUG4 +9 |INFO +10 |INFO2 +11 |INFO3 +12 |INFO4 +13 |WARN +14 |WARN2 +15 |WARN3 +16 |WARN4 +17 |ERROR +18 |ERROR2 +19 |ERROR3 +20 |ERROR4 +21 |FATAL +22 |FATAL2 +23 |FATAL3 +24 |FATAL4 + +When an individual log record is displayed it is recommended to show both +`SeverityText` and `SeverityNumber` values. A recommended combined string in +this case begins with the short name followed by `SeverityText` in parenthesis. + +For example "Informational" Syslog record will be displayed as **INFO +(Informational)**. When for a particular log record the `SeverityNumber` is +defined but the `SeverityText` is missing it is recommended to only show the +short name, e.g. **INFO**. + +When drop down lists (or other UI elements that are intended to represent the +possible set of values) are used for representing the severity it is preferable +to display the short name in such UI elements. + +For example a dropdown list of severities that allows filtering log records by +severities is likely to be more usable if it contains the short names of +`SeverityNumber` (and thus has a limited upper bound of elements) compared to a +dropdown list, which lists all distinct `SeverityText` values that are known to +the system (which can be a large number of elements, often differing only in +capitalization or abbreviated, e.g. "Info" vs "Information"). + +#### Comparing Severity + +In the contexts where severity participates in less-than / greater-than +comparisons `SeverityNumber` field should be used. `SeverityNumber` can be +compared to another `SeverityNumber` or to numbers in the 1..24 range (or to the +corresponding short names). + +When severity is used in equality or inequality comparisons (for example in +filters in the UIs) the recommendation is to attempt to use both `SeverityText` +and short name of `SeverityNumber` to perform matches (i.e. equality with either +of these fields should be considered a match). For example if we have a record +with `SeverityText` field equal to "Informational" and `SeverityNumber` field +equal to INFO then it may be preferable from the user experience perspective to +ensure that **severity="Informational"** and **severity="INFO"** conditions both +to are TRUE for that record. + +### Field: `ShortName` + +Type: string. + +Description: Short event identifier that does not contain varying parts. +`ShortName` describes what happened (e.g. "ProcessStarted"). Recommended to be +no longer than 50 characters. Not guaranteed to be unique in any way. Typically +used for filtering and grouping purposes in backends. This field is optional. + +### Field: `Body` + +Type: any. + +Description: A value containing the body of the log record (see the description +of `any` type above). Can be for example a human-readable string message +(including multi-line) describing the event in a free form or it can be a +structured data composed of arrays and maps of other values. Can vary for each +occurrence of the event coming from the same source. This field is optional. + +### Field: `Resource` + +Type: key/value pair list. + +Description: Describes the source of the log, aka +[resource](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/overview.md#resources). +"key" of each pair is a `string` and "value" is of `any` type. Multiple +occurrences of events coming from the same event source can happen across time +and they all have the same value of `Resource`. Can contain for example +information about the application that emits the record or about the +infrastructure where the application runs. Data formats that represent this data +model may be designed in a manner that allows the `Resource` field to be +recorded only once per batch of log records that come from the same source. +SHOULD follow OpenTelemetry +[semantic conventions for Resources](https://github.com/open-telemetry/opentelemetry-specification/tree/master/specification/resource/semantic_conventions). +This field is optional. + +### Field: `Attributes` + +Type: key/value pair list. + +Description: Additional information about the specific event occurrence. "key" +of each pair is a `string` and "value" is of `any` type. Unlike the `Resource` +field, which is fixed for a particular source, `Attributes` can vary for each +occurrence of the event coming from the same source. Can contain information +about the request context (other than TraceId/SpanId). SHOULD follow +OpenTelemetry +[semantic conventions for Attributes](https://github.com/open-telemetry/opentelemetry-specification/tree/master/specification/trace/semantic_conventions). +This field is optional. + +## Example Log Records + +Below are examples that show one possible representation of log records in JSON. +These are just examples to help understand the data model. Don’t treat the +examples as _the_ way to represent this data model in JSON. + +This document does not define the actual encoding and format of the log record +representation. Format definitions will be done in separate OTEPs (e.g. the log +records may be represented as msgpack, JSON, Protocol Buffer messages, etc). + +Example 1 + +```javascript +{ + "Timestamp": 1586960586000, // JSON needs to make a decision about + // how to represent nanoseconds. + "Attributes": { + "http.status_code": 500, + "http.url": "http://example.com", + "my.custom.application.tag": "hello", + }, + "Resource": { + "service.name": "donut_shop", + "service.version": "semver:2.0.0", + "k8s.pod.uid": "1138528c-c36e-11e9-a1a7-42010a800198", + }, + "TraceId": "f4dbb3edd765f620", // this is a byte sequence + // (hex-encoded in JSON) + "SpanId": "43222c2d51a7abe3", + "SeverityText": "INFO", + "SeverityNumber": 9, + "Body": "20200415T072306-0700 INFO I like donuts" +} +``` + +Example 2 + +```javascript +{ + "Timestamp": 1586960586000, + ... + "Body": { + "i": "am", + "an": "event", + "of": { + "some": "complexity" + } + } +} +``` + +Example 3 + +```javascript +{ + "Timestamp": 1586960586000, + "Attributes":{ + "http.scheme":"https", + "http.host":"donut.mycie.com", + "http.target":"/order", + "http.method":"post", + "http.status_code":500, + "http.flavor":"1.1", + "http.user_agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36", + } +} +``` + +## Questions Resolved during OTEP discussion + +These were Open Questions that were discussed and resolved in +[OTEP Pull Request]( https://github.com/open-telemetry/oteps/pull/97) + +### TraceFlags vs TraceParent and TraceState + +Question: Should we store entire +[W3C Trace Context](https://www.w3.org/TR/trace-context/), including +`traceparent` and `tracestate` fields instead of only `TraceFlags`? + +Answer: the discussion did not reveal any evidence that `traceparent` and +`tracestate` are needed. + +### Severity Fields + +Question: Is `SeverityText`/`SeverityNumber` fields design good enough? + +Answer: Discussions have shown that the design is reasonable. + +### Timestamp Requirements + +Question: Early draft of this proposal specified that `Timestamp` should be +populated from a monotonic, NTP-synchronized source. We removed this requirement +to avoid confusion. Do we need any requirements for timestamp sources? + +Answer: discussions revealed that it is not data model's responsibility to +specify such requirements. + +### Security Logs + +Question: Is there a need for special treatment of security logs? + +Answer: discussions in the OTEP did not reveal the need for any special +treatment of security logs in the context of the data model proposal. + +## Alternate Design + +An +[alternate design](https://docs.google.com/document/d/1ix9_4TQO3o-qyeyNhcOmqAc1MTyr-wnXxxsdWgCMn9c/edit?ts=5e990fe2#heading=h.cw69q2ga62p6) +that used an envelop approach was considered but I did not find it to be overall +better than this one. + +## Prior Art + +### RFC5424 Syslog + +[RFC5424](https://tools.ietf.org/html/rfc5424) defines structured log data +format and protocol. The protocol is ubiquitous (although unfortunately many +implementations don’t follow structured data recommendations). Here are some +drawbacks that do not make Syslog a serious contender for a data model: + +- While it allows structured attributes the body of the message can be only a + string. + +- Severity is hard-coded to 8 possible numeric values, and does not allow custom + severity texts. + +- Structured data does not allow arbitrary nesting and is 2-level only. + +- No clear separate place to specify data source (aka resource). There are a + couple hard-coded fields that serve this purpose in a limited way (HOSTNAME, + APP-NAME, FACILITY). + +### Fluentd Forward Protocol Model + +[Forward protocol](https://github.com/fluent/fluentd/wiki/Forward-Protocol-Specification-v1) +defines a log Entry concept as a timestamped record. The record consists of 2 +elements: a tag and a map of arbitrary key/value pairs. + +The model is universal enough to represent any log record. However, here are +some drawbacks: + +- All attributes of a record are represented via generic key/value pairs (except + tag and timestamp). This misses the optimization opportunities (see [Design + Notes](#design-notes)). + +- There is no clear separate place to specify data source (aka resource). + +- There is no mention of how exactly keys should be named and what are expected + values. This lack of any naming convention or standardization of key/value + pairs makes interoperability difficult. + +## Appendix A. Example Mappings + +This section contains examples of mapping of other events and logs formats to +this data model. + +### RFC5424 Syslog + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
PropertyTypeDescriptionMaps to Unified Model Field
TIMESTAMPTimestampTime when an event occurred measured by the origin clock.Timestamp
SEVERITYenumDefines the importance of the event. Example: `Debug`Severity
FACILITYenumDescribes where the event originated. A predefined list of Unix processes. Part of event source identity. Example: `mail system`Attributes["syslog.facility"]
VERSIONnumberMeta: protocol version, orthogonal to the event.Attributes["syslog.version"]
HOSTNAMEstringDescribes the location where the event originated. Possible values are FQDN, IP address, etc.Resource["host.hostname"]
APP-NAMEstringUser-defined app name. Part of event source identity.Resource["service.name"]
PROCIDstringNot well defined. May be used as a meta field for protocol operation purposes or may be part of event source identity.Attributes["syslog.procid"]
MSGIDstringDefines the type of the event. Part of event source identity. Example: "TCPIN"ShortName
STRUCTURED-DATAarray of maps of string to stringA variety of use cases depending on the SDID: +Can describe event source identity +Can include data that describes particular occurrence of the event. +Can be meta-information, e.g. quality of timestamp value.SDID origin.swVersion map to Resource["service.version"] + +SDID origin.ip map to attribute[net.host.ip"] + +Rest of SDIDs -> Attributes["syslog.*"]
MSGstringFree-form text message about the event. Typically human readable.Body
+ +### Windows Event Log + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
PropertyTypeDescriptionMaps to Unified Model Field
TimeCreatedTimestampThe time stamp that identifies when the event was logged.Timestamp
LevelenumContains the severity level of the event.Severity
ComputerstringThe name of the computer on which the event occurred.Resource["host.hostname"]
EventIDuintThe identifier that the provider used to identify the event.ShortName
MessagestringThe message string.Body
Rest of the fields.anyAll other fields in the event.Attributes["winlog.*"]
+ +### SignalFx Events + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FieldTypeDescriptionMaps to Unified Model Field
TimestampTimestampTime when the event occurred measured by the origin clock.Timestamp
EventTypestringShort machine understandable string describing the event type. SignalFx specific concept. Non-namespaced. Example: k8s Event Reason field.ShortName
CategoryenumDescribes where the event originated and why. SignalFx specific concept. Example: AGENT. Attributes["com.splunk.signalfx.event_category"]
Dimensionsmap of string to stringHelps to define the identity of the event source together with EventType and Category. Multiple occurrences of events coming from the same event source can happen across time and they all have the value of Dimensions. Resource
Propertiesmap of string to anyAdditional information about the specific event occurrence. Unlike Dimensions which are fixed for a particular event source, Properties can have different values for each occurrence of the event coming from the same event source.Attributes
+ +### Splunk HEC + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FieldTypeDescriptionMaps to Unified Model Field
timenumeric, stringThe event time in epoch time format, in seconds.Timestamp
hoststringThe host value to assign to the event data. This is typically the host name of the client that you are sending data from.Resource["host.hostname"]
sourcestringThe source value to assign to the event data. For example, if you are sending data from an app you are developing, you could set this key to the name of the app.Resource["service.name"]
sourcetypestringThe sourcetype value to assign to the event data.Attributes["source.type"]
eventanyThe JSON representation of the raw body of the event. It can be a string, number, string array, number array, JSON object, or a JSON array.Body
fieldsMap of anySpecifies a JSON object that contains explicit custom fields.Attributes
indexstringThe name of the index by which the event data is to be indexed. The index you specify here must be within the list of allowed indexes if the token has the indexes parameter set.TBD, most like will go to attributes
+ +### Log4j + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FieldTypeDescriptionMaps to Unified Model Field
InstantTimestampTime when an event occurred measured by the origin clock.Timestamp
LevelenumLog level.Severity
MessagestringHuman readable message.Body
All other fieldsanyStructured data.Attributes
+ +### Zap + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FieldTypeDescriptionMaps to Unified Model Field
tsTimestampTime when an event occurred measured by the origin clock.Timestamp
levelenumLogging level.Severity
callerstringCalling function's filename and line number. +Attributes, key=TBD
msgstringHuman readable message.Body
All other fieldsanyStructured data.Attributes
+ +### Apache HTTP Server access log + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FieldTypeDescriptionMaps to Unified Model Field
%tTimestampTime when an event occurred measured by the origin clock.Timestamp
%astringClient IPAttributes["net.peer.ip"]
%AstringServer IPAttributes["net.host.ip"]
%hstringRemote hostname. Attributes["net.peer.name"]
%mstringThe request method.Attributes["http.method"]
%v,%p,%U,%qstringMultiple fields that can be composed into URL.Attributes["http.url"]
%>sstringResponse status.Attributes["http.status_code"]
All other fieldsanyStructured data.Attributes, key=TBD
+ +### CloudTrail Log Event + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FieldTypeDescriptionMaps to Unified Model Field
eventTimestringThe date and time the request was made, in coordinated universal time (UTC).Timestamp
eventSourcestringThe service that the request was made to. This name is typically a short form of the service name without spaces plus .amazonaws.com.Resource["service.name"]?
awsRegionstringThe AWS region that the request was made to, such as us-east-2.Resource["cloud.region"]
sourceIPAddressstringThe IP address that the request was made from.Resource["net.peer.ip"] or Resource["net.host.ip"]? TBD
errorCodestringThe AWS service error if the request returns an error.ShortName
errorMessagestringIf the request returns an error, the description of the error.Body
All other fields*Attributes["cloudtrail.*"]
+ +### Google Cloud Logging + +Field | Type | Description | Maps to Unified Model Field +-----------------|--------------------| ------------------------------------------------------- | --------------------------- +timestamp | string | The time the event described by the log entry occurred. | Timestamp +resource | MonitoredResource | The monitored resource that produced this log entry. | Resource +log_name | string | The URL-encoded LOG_ID suffix of the log_name field identifies which log stream this entry belongs to. | ShortName +json_payload | google.protobuf.Struct | The log entry payload, represented as a structure that is expressed as a JSON object. | Body +proto_payload | google.protobuf.Any | The log entry payload, represented as a protocol buffer. | Body +text_payload | string | The log entry payload, represented as a Unicode string (UTF-8). | Body +severity | LogSeverity | The severity of the log entry. | Severity +trace | string | The trace associated with the log entry, if any. | TraceId +span_id | string | The span ID within the trace associated with the log entry. | SpanId +labels | map | A set of user-defined (key, value) data that provides additional information about the log entry. | Attributes +All other fields | | | Attributes["google.*"] + +## Elastic Common Schema + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
FieldTypeDescriptionMaps to Unified Model Field
@timestampdatetimeTime the event was recordedtimestamp
messagestringAny type of messagebody
labelskey/valueArbitrary labels related to the eventattributes[*]
tagsarray of stringList of values related to the event?
trace.idstringTrace IDTraceId
span.id*stringSpan IDSpanId
agent.ephemeral_idstringEphemeral ID created by agent**resource
agent.idstringUnique identifier of this agent**resource
agent.namestringName given to the agentresource["telemetry.sdk.name"]
agent.typestringType of agentresource["telemetry.sdk.language"]
agent.versionstringVersion of agentresource["telemetry.sdk.version"]
source.ip, client.ipstringThe IP address that the request was made from.attributes["net.peer.ip"] or attributes["net.host.ip"]
cloud.account.idstringID of the account in the given cloudresource["cloud.account.id"]
cloud.availability_zonestringAvailability zone in which this host is running.resource["cloud.zone"]
cloud.instance.idstringInstance ID of the host machine.**resource
cloud.instance.namestringInstance name of the host machine.**resource
cloud.machine.typestringMachine type of the host machine.**resource
cloud.providerstringName of the cloud provider. Example values are aws, azure, gcp, or digitalocean.resource["cloud.provider"]
cloud.regionstringRegion in which this host is running.resource["cloud.region"]
cloud.image.id*stringresource["host.image.name"]
container.idstringUnique container idresource["container.id"]
container.image.namestringName of the image the container was built on.resource["container.image.name"]
container.image.tagArray of stringContainer image tags.**resource
container.labelskey/valueImage labels.attributes[*]
container.namestringContainer name.resource["container.name"]
container.runtimestringRuntime managing this container. Example: "docker"**resource
destination.addressstringDestination address for the eventattributes["destination.address"]
error.codestringError code describing the error.attributes["error.code"]
error.idstringUnique identifier for the error.attributes["error.id"]
error.messagestringError message.attributes["error.message"]
error.stack_tracestringThe stack trace of this error in plain text.attributes["error.stack_trace]
host.architecturestringOperating system architecture**resource
host.domainstringName of the domain of which the host is a member. + +For example, on Windows this could be the host’s Active Directory domain or NetBIOS domain name. For Linux this could be the domain of the host’s LDAP provider.**resource
host.hostnamestringHostname of the host. + +It normally contains what the hostname command returns on the host machine.resource["host.hostname"]
host.idstringUnique host id.resource["host.id"]
host.ipArray of stringHost IPresource["host.ip"]
host.macarray of stringMAC addresses of the hostresource["host.mac"]
host.namestringName of the host. + +It may contain what hostname returns on Unix systems, the fully qualified, or a name specified by the user. resource["host.name"]
host.typestringType of host.resource["host.type"]
host.uptimestringSeconds the host has been up.?
service.ephemeral_id + +stringEphemeral identifier of this service**resource
service.idstringUnique identifier of the running service. If the service is comprised of many nodes, the service.id should be the same for all nodes.**resource
service.namestringName of the service data is collected from.resource["service.name"]
service.node.namestringSpecific node serving that serviceresource["service.instance.id"]
service.statestringCurrent state of the service.attributes["service.state"]
service.typestringThe type of the service data is collected from.**resource
service.versionstringVersion of the service the data was collected from.resource["service.version"]
+ +\* Not yet formalized into ECS. + +\*\* A resource that doesn’t exist in the +[OpenTelemetry resource semantic convention](https://github.com/open-telemetry/opentelemetry-specification/tree/master/specification/resource/semantic_conventions). + +This is a selection of the most relevant fields. See +[for the full reference](https://www.elastic.co/guide/en/ecs/current/ecs-field-reference.html) +for an exhaustive list. + +## Appendix B: `SeverityNumber` example mappings + +|Syslog |WinEvtLog |Log4j |Zap |java.util.logging|SeverityNumber| +|-------------|-----------|------|------|-----------------|--------------| +| | |TRACE | | FINEST |TRACE | +|Debug |Verbose |DEBUG |Debug | FINER |DEBUG | +| | | | | FINE |DEBUG2 | +| | | | | CONFIG |DEBUG3 | +|Informational|Information|INFO |Info | INFO |INFO | +|Notice | | | | |INFO2 | +|Warning |Warning |WARN |Warn | WARNING |WARN | +|Error |Error |ERROR |Error | SEVERE |ERROR | +|Critical |Critical | |Dpanic| |ERROR2 | +|Emergency | | |Panic | |ERROR3 | +|Alert | |FATAL |Fatal | |FATAL | + +## References + +- [Draft discussion of Data Model](https://docs.google.com/document/d/1ix9_4TQO3o-qyeyNhcOmqAc1MTyr-wnXxxsdWgCMn9c/edit#) + +- [Discussion of Severity field](https://docs.google.com/document/d/1WQDz1jF0yKBXe3OibXWfy3g6lor9SvjZ4xT-8uuDCiA/edit#)