MicroProfile Telemetry log events reference list

MicroProfile Telemetry can collect logging events from the server runtime and applications. You can use these events to gather and analyze data that can help to better understand the behavior of applications.

For more information, see Enable observability with MicroProfile Telemetry.

MicroProfile Telemetry can collect the following types of events:

Message events
Trace events
FFDC events

For information about trace log detail levels and how Open Liberty settings map to OpenTelemetry severity numbers, see OpenTelemetry severity number mapping with Liberty log levels.

Message events

The following table provides the fields for Liberty message events, a description for each field, and the mapping to the OpenTelemetry logs data model and Java agent:

Message event fields
Liberty message event fields	Description	Maps to OpenTelemetry logs data model	OpenTelemetry Java agent (JUL) mapping
type	A string that identifies the type of event.	Attributes[`io.openliberty.type`]	N/A
host	Host name of the server that is the source of the event.	Resource[`host.name`]	Resource[`host.name`]
message	The message from the log record, starting with the message ID.	Body	body
ibm_threadId	Thread ID in the log line, for example, 00000015.	Attributes[`thread.id`]	N/A
ibm_datetime	Time at which the event occurred.	TimeStamp	TimeStamp
ibm_messageId	Message ID in the log line.	Attributes[`io.openliberty.message_id`]	N/A
module	Logger name from the log record.	Attributes[`io.openliberty.module`]	N/A
loglevel	Severity indicator	SeverityText	SeverityText
ibm_methodName	Method name from the log record.	Attributes[`io.openliberty.method_name`]	N/A
ibm_className	Class name from the log record.	Attributes[`io.openliberty.class_name`]	N/A
ibm_sequence	Sequence number of the event,.	Attributes[`io.openliberty.sequence`]	N/A
ext_thread	Name of the thread that is the source of the event.	Attributes[`thread.name`]	N/A
ext_appName	Name of the application that logged the message.	Attributes[`io.openliberty.ext.app_name`]	N/A

The following example shows the OpenTelemetry Collector output for a message event from an application:

timeUnixNano="1717512929163000000"
observeTimeUnixNano="1717512929602000000"
severityNumber="13"
severityText="W"
body=" BADAP0001W: Test Warning."
traceId="a4fa4f34167d2bcbcfb94588d37b332"
spanId="63522117c3492d42"
Attributes:
            io.openliberty.type="liberty_message"
            io.openliberty.message_id="BADAP0001W"
            io.openliberty.sequence="1717512929163_0000000000012
            io.openliberty.module="com.ibm.ws.lumberjack.badness.Angry"
            thread.id="65"
            thread.name="Default Executor-thread-2"
            io.openliberty.ext.app_name="badapp"

Trace events

The following table provides the fields for Liberty trace events, a description for each field, and the mapping to the OpenTelemetry logs data model and Java agent:

Trace event fields
Liberty trace event fields	Description	Maps to OpenTelemetry Logs Data Model	OpenTelemetry Java Agent JUL Mapping
type	A string that identifies the type of event.	Attributes[`io.openliberty.type`]	N/A
host	Host name of the server that is the source of the event.	Resource[`host.name`]	Resource[`host.name`]
message	The message from the log record, starting with the message ID.	Body	body
ibm_threadId	Thread ID in the log line, for example, 00000015.	Attributes[`thread.id`]	N/A
ibm_datetime	Time at which the event occurred.	TimeStamp	TimeStamp
ibm_messageId	Message ID in the log line.	Attributes[`io.openliberty.message_id`]	N/A
module	Logger name from the log record.	Attributes[`io.openliberty.module`]	N/A
loglevel	Severity indicator	SeverityText	SeverityText
ibm_methodName	Method name from the log record.	Attributes[`io.openliberty.method_name`]	N/A
ibm_className	Class name from the log record.	Attributes[`io.openliberty.class_name`]	N/A
ibm_sequence	Sequence number of the event,.	Attributes[`io.openliberty.sequence`]	N/A
ext_thread	Name of the thread that is the source of the event.	Attributes[`thread.name`]	N/A
ext_appName	Name of the application that logged the message.	Attributes[`io.openliberty.ext.app_name`]	N/A

The following example shows the OpenTelemetry Collector output for a trace event from an application:

timeUnixNano="11234512231363000000"
observeTimeUnixNano="17123512929602000000"
severityNumber="1"
severityText="3"
body="finest trace"
traceId="3fced7fbfbc062349c66a8c1a37c31b2"
spanId="4be39c323e375d9e"
Attributes:
            io.openliberty.type="liberty_trace"
            io.openliberty.sequence="12312363_0000000000021"
            io.openliberty.module="com.test.app"
            thread.id="79"
            thread.name="Default Executor-thread-12"
            io.openliberty.ext.app_name="testapp"

FFDC events

The following table provides the fields for the first failure data capture (FFDC) events, a description for each fiel, and the mapping to the OpenTelemetry logs data model:

FFDC event fields
Liberty FFDC event fields	Description	Maps to OpenTelemetry Logs Data Model
type	A string that identifies the type of event.	Attributes[`io.openliberty.type`]
host	Host name of the server that is the source of the event.	Resource[`host.name`]
ibm_datetime	Time at which the event occurred.	TimeStamp
message	The message from the exception that triggered the event.	body and Attributes[`exception.message`]
ibm_className	The class that emitted the FFDC event.	Attributes[`io.openliberty.class_name`]
ibm_exceptionName	The exception that is reported in the FFDC event.	Attributes[`exception.type`]
ibm_probeID	The unique identifier of the FFDC point within the class.	Attributes[`io.openliberty.probe_id`]
ibm_threadId	The thread ID of the FFDC event.	Attributes[`thread.id`]
ibm_stackTrace	The stack trace of the FFDC event.	Attributes[`exception.stacktrace`]
ibm_objectDetails	The incident details for the FFDC event.	Attributes[`io.openliberty.object_details`]
ibm_sequence	Sequence number of the event, which is useful for sorting records with the same timestamp.	Attributes[`io.openliberty.sequence`]

The following example shows the OpenTelemetry Collector output for an FFDC event from an application:

timeUnixNano=“1232335231363000000”
observeTimeUnixNano=“123455512929602000000”
severityNumber=“13”
body="Cannot invoke "java.lang.String.toString()" because "myString" is null"
traceId=“3fced7fbfbc062349c66a8c1a37c31b2”
spanId=“4be39c323e375d9e”
Attributes:
            io.openliberty.type="liberty_ffdc"
            exception.message="Cannot invoke "java.lang.String.toString()" because "myString" is null"
            exception.stacktrace="java.lang.NullPointerException: Cannot invoke "java.lang.String.toString()" because "myString" is null\n\tat io.openliberty.microprofile.telemetry.logging.internal.container.fat.MpTelemetryLogApp.MpTelemetryServlet.doGet(MpTelemetryServlet.java:53) ..."
            exception.type= "java.lang.NullPointerException"
            io.openliberty.class_name="io.openliberty.microprofile.telemetry.logging.internal.container.fat.MpTelemetryLogApp"
            io.openliberty.object_details="Object type = io.openliberty.microprofile.telemetry.logging.internal.container.fat.MpTelemetryLogApp\n tc = class             com.ibm.websphere.ras.TraceComponent@7baa4ff8 ...
            io.openliberty.probe_id="62"
            io.openliberty.sequence=“1723140654466_00000000000011"
            thread.id=“92”
            thread.name=“Default Executor-thread-12”

OpenTelemetry severity number mapping with Open Liberty log levels

You can set the level of detail that your Open Liberty logs collect by configuring the traceSpecification attribute for the logging attribute in your server.xml file. For more information about Liberty log levels, see Trace log detail levels.

The following table describes how the different Liberty log levels map to severity numbers and short names from the OpenTelemetry specification.

Open Liberty log levels and OpenTelemetry severity numbers
Liberty log levels	OpenTelemetry severity short Name	OpenTelemetry severity meaning	OpenTelemetry severity number
fatal	FATAL	A fatal error such as application or system crash.	21
severe	ERROR	An error event. Something went wrong.	17
warning	WARN	A warning event. Not an error but is likely more important than an informational event.	13
audit	INFO2	An informational event. Indicates that an event happened.	10
info	INFO	-	9
config	DEBUG4	A debugging event.	8
detail	DEBUG3	-	7
fine	DEBUG2	-	6
finer	DEBUG	-	5
finest	TRACE	A fine-grained debugging event. Typically disabled in default configurations.	1