
:guide-id: tracing
:guide-title: Root cause analysis with tracing
:guide-summary: Record information during the request lifecycle with OpenTelementry tracing to identify root cases for latencies and errors in {project_name} and connected systems.
:guide-priority: 999
:guide-tile-visible: true
:version: 26.2.2

include::../attributes.adoc[]

[[tracing]]
= Root cause analysis with tracing

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endif::[]
ifeval::["" != ""]
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This {section} explains how you can enable and configure distributed tracing in {project_name} by utilizing https://opentelemetry.io/[OpenTelemetry] (OTel).
Tracing allows for detailed monitoring of each request's lifecycle, which helps quickly identify and diagnose issues, leading to more efficient debugging and maintenance.

It provides valuable insights into performance bottlenecks and can help optimize the system's overall efficiency and across system boundaries.
{project_name} uses a supported https://quarkus.io/guides/opentelemetry-tracing[Quarkus OTel extension] that provides smooth integration and exposure of application traces.

== Enable tracing

It is possible to enable exposing traces using the build time option `tracing-enabled` as follows:

[source,bash]
----
bin/kc.[sh|bat] start --tracing-enabled=true
----

By default, the trace exporters send out data in batches, using the `gRPC` protocol and endpoint `+http://localhost:4317+`.

The default service name is `keycloak`, specified via the `tracing-service-name` property, which takes precedence over `service.name` defined in the `tracing-resource-attributes` property.

For more information about resource attributes that can be provided via the `tracing-resource-attributes` property, see the https://quarkus.io/guides/opentelemetry#resource[Quarkus OpenTelemetry Resource] guide.

NOTE: Tracing can be enabled only when the `opentelemetry` feature is *enabled* (by default).

For more tracing settings, see all possible configurations below.

== Development setup

In order to see the captured {project_name} traces, the basic setup with leveraging the https://www.jaegertracing.io/[Jaeger] tracing platform might be used.
For development purposes, the Jaeger-all-in-one can be used to see traces as easily as possible.

NOTE: Jaeger-all-in-one includes the Jaeger agent, an OTel collector, and the query service/UI.
You do not need to install a separate collector, as you can directly send the trace data to Jaeger.

[source, bash]
----
podman|docker run --name jaeger \
-p 16686:16686 \
-p 4317:4317 \
-p 4318:4318 \
jaegertracing/all-in-one
----

=== Exposed ports

`16686`:: Jaeger UI
`4317`:: OpenTelemetry Protocol gRPC receiver (default)
`4318`:: OpenTelemetry Protocol HTTP receiver

You can visit the Jaeger UI on `+http://localhost:16686/+` to see the tracing information.
The Jaeger UI might look like this with an arbitrary {project_name} trace:

image::jaeger-tracing.png[Jaeger UI]

== Information in traces

=== Spans

{project_name} creates spans for the following activities:

* Incoming HTTP requests
* Outgoing Database including acquiring a database connections
* Outgoing LDAP requests including connecting to the LDAP server
* Outgoing HTTP requests including IdP brokerage

=== Tags

{project_name} adds tags to traces depending on the type of the request. All tags are prefixed with `kc.`.

Example tags are:

`kc.clientId`:: Client ID

`kc.realmName`:: Realm name

`kc.sessionId`:: User session ID

`kc.token.id`:: `id` as mentioned in the token

`kc.token.issuer`:: `issuer` as mentioned in the token

`kc.token.sid`:: `sid` as mentioned in the token

`kc.authenticationSessionId`:: Authentication session ID

`kc.authenticationTabId`:: Authentication Tab ID

=== Logs

If a trace is being sampled, it will contain any user events created during the request.
This includes, for example, `LOGIN`, `LOGOUT` or `REFRESH_TOKEN` events with all details and IDs found in user events.

LDAP communication errors are shown as log entries in recorded traces as well with a stack trace and details of the failed operation.

== Trace IDs in logs

When tracing is enabled, the trace IDs are included in the log messages of all enabled log handlers (see more in link:{links_server_logging_url}[{links_server_logging_name}]).
It can be useful for associating log events to request execution, which might provide better traceability and debugging.
All log lines originating from the same request will have the same `traceId` in the log.

The log message also contains a `sampled` flag, which relates to the sampling described below and indicates whether the span was sampled - sent to the collector.

The format of the log records may start as follows:

[source, bash]
----
2024-08-05 15:27:07,144 traceId=b636ac4c665ceb901f7fdc3fc7e80154, parentId=d59cea113d0c2549, spanId=d59cea113d0c2549, sampled=true WARN  [org.keycloak.events] ...
----

=== Hide trace IDs in logs

You can hide trace IDs in specific log handlers by specifying their associated {project_name} option `log-<handler-name>-include-trace`, where `<handler-name>` is the name of the log handler.
For instance, to disable trace info in the `console` log, you can turn it off as follows:

[source,bash]
----
bin/kc.[sh|bat] start --tracing-enabled=true --log=console --log-console-include-trace=false
----

NOTE: When you explicitly override the log format for the particular log handlers, the `*-include-trace` options do not have any effect, and no tracing is included.

[[sampling]]
== Sampling

The sampler decides whether a trace should be discarded or forwarded, effectively reducing overhead by limiting the number of collected traces sent to the collector.
It helps manage resource consumption, which leads to avoiding the huge storage costs of tracing every single request and potential performance penalty.

WARNING: For a production-ready environment, sampling should be properly set to minimize infrastructure costs.

{project_name} supports several built-in OpenTelemetry samplers, such as:

        * `+always_on+`  
        * `+always_off+`  
        * `+traceidratio+`  (default) 
        * `+parentbased_always_on+`  
        * `+parentbased_always_off+`  
        * `+parentbased_traceidratio+`  

The used sampler can be changed via the `tracing-sampler-type` property.

=== Default sampler
The default sampler for {project_name} is `traceidratio`, which controls the rate of trace sampling based on a specified ratio configurable via the `tracing-sampler-ratio` property.

==== Trace ratio
The default trace ratio is `1.0`, which means all traces are sampled - sent to the collector.
The ratio is a floating number in the range `[0,1]`.
For instance, when the ratio is `0.1`, only 10% of the traces are sampled.

WARNING: For a production-ready environment, the trace ratio should be a smaller number to prevent the massive cost of trace store infrastructure and avoid performance overhead.

TIP: The ratio can be set to `0.0` to disable sampling entirely _at runtime_.

==== Rationale

The sampler makes its own sampling decisions based on the current ratio of sampled spans, regardless of the decision made on the parent span,
as with using the `parentbased_traceidratio` sampler.

The `parentbased_traceidratio` sampler could be the preferred default type as it ensures the sampling consistency between parent and child spans.
Specifically, if a parent span is sampled, all its child spans will be sampled as well - the same sampling decision for all.
It helps to keep all spans together and prevents storing incomplete traces.

However, it might introduce certain security risks leading to DoS attacks.
External callers can manipulate trace headers, parent spans can be injected, and the trace store can be overwhelmed.
Proper HTTP headers (especially `tracestate`) filtering and adequate measures of caller trust would need to be assessed.

For more information, see the https://www.w3.org/TR/trace-context/#security-considerations[W3C Trace context] document.

== Tracing in Kubernetes environment
When the tracing is enabled when using the {project_name} Operator, certain information about the deployment is propagated to the underlying containers.

=== Configuration via Keycloak CR

You can change tracing configuration via Keycloak CR. For more information, see the link:{links_operator_advanced-configuration_url}#_tracing_opentelemetry[{links_operator_advanced-configuration_name}].

=== Filter traces based on Kubernetes attributes
You can filter out the required traces in your tracing backend based on their tags:

* `service.name` - {project_name} deployment name
* `k8s.namespace.name` - Namespace
* `host.name` - Pod name

{project_name} Operator automatically sets the `KC_TRACING_SERVICE_NAME` and `KC_TRACING_RESOURCE_ATTRIBUTES` environment variables for each {project_name} container included in pods it manages.

NOTE: The `KC_TRACING_RESOURCE_ATTRIBUTES` variable always contains (if not overridden) the `k8s.namespace.name` attribute representing current namespace.


== Relevant options

[cols="12a,4",role="options"]
|===
| |Value

|
[.options-key]#``log-console-include-trace``# 

[.options-description]#Include tracing information in the console log.#

[role="options-extended"]
--
[.options-description-extended]#If the `log-console-format` option is specified, this option has no effect.#

*CLI:* `--log-console-include-trace` +
*Env:* `KC_LOG_CONSOLE_INCLUDE_TRACE`
--

Available only when Console log handler and Tracing is activated


|
`+true+` (default), `+false+`

|
[.options-key]#``log-file-include-trace``# 

[.options-description]#Include tracing information in the file log.#

[role="options-extended"]
--
[.options-description-extended]#If the `log-file-format` option is specified, this option has no effect.#

*CLI:* `--log-file-include-trace` +
*Env:* `KC_LOG_FILE_INCLUDE_TRACE`
--

Available only when File log handler and Tracing is activated


|
`+true+` (default), `+false+`

|
[.options-key]#``log-syslog-include-trace``# 

[.options-description]#Include tracing information in the Syslog.#

[role="options-extended"]
--
[.options-description-extended]#If the `log-syslog-format` option is specified, this option has no effect.#

*CLI:* `--log-syslog-include-trace` +
*Env:* `KC_LOG_SYSLOG_INCLUDE_TRACE`
--

Available only when Syslog handler and Tracing is activated


|
`+true+` (default), `+false+`

|
[.options-key]#``tracing-compression``# 

[.options-description]#OpenTelemetry compression method used to compress payloads.#

[role="options-extended"]
--
[.options-description-extended]#If unset, compression is disabled.#

*CLI:* `--tracing-compression` +
*Env:* `KC_TRACING_COMPRESSION`
--

Available only when Tracing is enabled


|
`+gzip+`, `+none+` (default)

|
[.options-key]#``tracing-enabled``# [.none]#icon:tools[role=options-build]#

[.options-description]#Enables the OpenTelemetry tracing.#

[role="options-extended"]
--


*CLI:* `--tracing-enabled` +
*Env:* `KC_TRACING_ENABLED`
--

Available only when 'opentelemetry' feature is enabled


|
`+true+`, `+false+` (default)

|
[.options-key]#``tracing-endpoint``# 

[.options-description]#OpenTelemetry endpoint to connect to.#

[role="options-extended"]
--


*CLI:* `--tracing-endpoint` +
*Env:* `KC_TRACING_ENDPOINT`
--

Available only when Tracing is enabled


|[.options-default]#`+http://localhost:4317+`# (default)

|
[.options-key]#``tracing-jdbc-enabled``# [.none]#icon:tools[role=options-build]#

[.options-description]#Enables the OpenTelemetry JDBC tracing.#

[role="options-extended"]
--


*CLI:* `--tracing-jdbc-enabled` +
*Env:* `KC_TRACING_JDBC_ENABLED`
--

Available only when Tracing is enabled


|
`+true+` (default), `+false+`

|
[.options-key]#``tracing-protocol``# 

[.options-description]#OpenTelemetry protocol used for the telemetry data.#

[role="options-extended"]
--


*CLI:* `--tracing-protocol` +
*Env:* `KC_TRACING_PROTOCOL`
--

Available only when Tracing is enabled


|
`+grpc+` (default), `+http/protobuf+`

|
[.options-key]#``tracing-resource-attributes``# 

[.options-description]#OpenTelemetry resource attributes present in the exported trace to characterize the telemetry producer.#

[role="options-extended"]
--
[.options-description-extended]#Values in format `key1=val1,key2=val2`. For more information, check the Tracing guide.#

*CLI:* `--tracing-resource-attributes` +
*Env:* `KC_TRACING_RESOURCE_ATTRIBUTES`
--

Available only when Tracing is enabled


|

|
[.options-key]#``tracing-sampler-ratio``# 

[.options-description]#OpenTelemetry sampler ratio.#

[role="options-extended"]
--
[.options-description-extended]#Probability that a span will be sampled. Expected double value in interval [0,1].#

*CLI:* `--tracing-sampler-ratio` +
*Env:* `KC_TRACING_SAMPLER_RATIO`
--

Available only when Tracing is enabled


|[.options-default]#`+1.0+`# (default)

|
[.options-key]#``tracing-sampler-type``# [.none]#icon:tools[role=options-build]#

[.options-description]#OpenTelemetry sampler to use for tracing.#

[role="options-extended"]
--


*CLI:* `--tracing-sampler-type` +
*Env:* `KC_TRACING_SAMPLER_TYPE`
--

Available only when Tracing is enabled


|
`+always_on+`, `+always_off+`, `+traceidratio+` (default), `+parentbased_always_on+`, `+parentbased_always_off+`, `+parentbased_traceidratio+`

|
[.options-key]#``tracing-service-name``# 

[.options-description]#OpenTelemetry service name.#

[role="options-extended"]
--
[.options-description-extended]#Takes precedence over `service.name` defined in the `tracing-resource-attributes` property.#

*CLI:* `--tracing-service-name` +
*Env:* `KC_TRACING_SERVICE_NAME`
--

Available only when Tracing is enabled


|[.options-default]#`+keycloak+`# (default)


|===
