IBM WebSphere Application Server Performance Cookbook

WebSphere Liberty OpenTelemetry log Recipe

WebSphere Liberty OpenTelemetry may be used to periodically log performance statistics to disk.

  1. The mpTelemetry feature must be installed. If needed, verify with productInfo; for example: 
    $ LIBERTY/bin/productInfo featureInfo | grep mpTelemetry
mpTelemetry-2.1
    • If it's not installed, you may install it with installUtility and then restart Liberty; for example: 
      LIBERTY/bin/installUtility install mpTelemetry-2.1
  2. Set the following environment variables to send the data to messages.log; for example, in server.env. 
    OTEL_SDK_DISABLED=false
OTEL_SERVICE_NAME=otellog
OTEL_LOGS_EXPORTER=none
OTEL_TRACES_EXPORTER=none
OTEL_METRICS_EXPORTER=console
OTEL_JAVA_DISABLED_RESOURCE_PROVIDERS=io.opentelemetry.instrumentation.resources.HostResourceProvider,io.opentelemetry.instrumentation.resources.ProcessResourceProvider,io.opentelemetry.instrumentation.resources.OsResourceProvider,io.opentelemetry.instrumentation.resources.ProcessRuntimeResourceProvider
  3. Add the mpTelemetry-2.1 feature to server.xml (or a configDropin override). For example: 
    <featureManager><feature>mpTelemetry-2.1</feature></featureManager>
    1. Note that Liberty defaults to a maximum of 20MB for messages.log with up to one historical file. If needed, you may increase this; for example, for a total of up to 1GB with 10 files up to 100MB each: 
      <logging maxFileSize="100" maxFiles="10"  />
  4. Restart Liberty.
  5. Approximately every minute, you should see OpenTelemetry statistics output in messages.log; for example, here's a statistic output for active threads (io.openliberty.threadpool.active_threads) for the Default Executor thread pool showing value=0 over 3 minutes: 
    [8/19/26, 10:39:21:572 CDT] 00000045 io.opentelemetry.exporter.logging.LoggingMetricExporter      I metric: ImmutableMetricData{resource=Resource{schemaUrl=null, attributes={service.instance.id="8b388da6-56ea-4920-8b1c-23076e381adf", service.name="otellog", telemetry.sdk.language="java", telemetry.sdk.name="opentelemetry", telemetry.sdk.version="1.48.0"}}, instrumentationScopeInfo=InstrumentationScopeInfo{name=io.openliberty.monitor.metrics, version=null, schemaUrl=null, attributes={}}, name=io.openliberty.threadpool.active_threads, description=The number of threads that are actively running tasks., unit={thread}, type=LONG_SUM, data=ImmutableSumData{points=[ImmutableLongPointData{startEpochNanos=1787153901540000000, epochNanos=1787153961544000000, attributes={io.openliberty.threadpool.name="Default Executor"}, value=0, exemplars=[]}], monotonic=false, aggregationTemporality=CUMULATIVE}}
[8/19/26, 10:40:21:559 CDT] 00000045 io.opentelemetry.exporter.logging.LoggingMetricExporter      I metric: ImmutableMetricData{resource=Resource{schemaUrl=null, attributes={service.instance.id="8b388da6-56ea-4920-8b1c-23076e381adf", service.name="otellog", telemetry.sdk.language="java", telemetry.sdk.name="opentelemetry", telemetry.sdk.version="1.48.0"}}, instrumentationScopeInfo=InstrumentationScopeInfo{name=io.openliberty.monitor.metrics, version=null, schemaUrl=null, attributes={}}, name=io.openliberty.threadpool.active_threads, description=The number of threads that are actively running tasks., unit={thread}, type=LONG_SUM, data=ImmutableSumData{points=[ImmutableLongPointData{startEpochNanos=1787153901540000000, epochNanos=1787154021544000000, attributes={io.openliberty.threadpool.name="Default Executor"}, value=0, exemplars=[]}], monotonic=false, aggregationTemporality=CUMULATIVE}}
[8/19/26, 10:41:21:550 CDT] 00000045 io.opentelemetry.exporter.logging.LoggingMetricExporter      I metric: ImmutableMetricData{resource=Resource{schemaUrl=null, attributes={service.instance.id="8b388da6-56ea-4920-8b1c-23076e381adf", service.name="otellog", telemetry.sdk.language="java", telemetry.sdk.name="opentelemetry", telemetry.sdk.version="1.48.0"}}, instrumentationScopeInfo=InstrumentationScopeInfo{name=io.openliberty.monitor.metrics, version=null, schemaUrl=null, attributes={}}, name=io.openliberty.threadpool.active_threads, description=The number of threads that are actively running tasks., unit={thread}, type=LONG_SUM, data=ImmutableSumData{points=[ImmutableLongPointData{startEpochNanos=1787153901540000000, epochNanos=1787154081545000000, attributes={io.openliberty.threadpool.name="Default Executor"}, value=0, exemplars=[]}], monotonic=false, aggregationTemporality=CUMULATIVE}}
  6. Reproduce the problem.
  7. Upload the following files:
    1. logs/messages*log
    2. logs/console.log
    3. logs/ffdc/*