Interpret the JVM log files

The JVM logs contain print data written by applications. The data may be written directly by the application in the form of System.out.print(), System.err.print(), etc, method calls. Data may also be written indirectly by the application calling a JVM function, such as Exception.printStackTrace(). In addition, the System.out JVM log contains system messages written by the WebSphere application server.

Depending on how the JVM log is configured, application print data may be formatted to look like WebSphere system messages, or may be displayed as plain text with no additional formatting. WebSphere system messages are always formatted.

Formatted messages may be written to the JVM logs in either basic or advanced format, depending on how the JVM log is configured.

This information describes the two formats and the fields that make up the messages.

Message formats

Formatted messages may be written to the JVM logs in one of two formats:

Basic Format

This is the format used in earlier versions of WebSphere application server.

Advanced Format

Extends the basic format by adding information about an event, when possible.

Basic and advanced format fields

Basic and Advanced Formats use many of the same fields and formatting techniques. The various fields that may be found in these formats include:

TimeStamp

The timestamp is formatted using the locale of the process where it is formatted. It includes a fully qualified date (for example YYMMDD) , 24 hour time with millisecond precision and a time zone.

ThreadId

An 8 character hexidecimal value generated from the hash code of the thread that issued the message.

ShortName

The abbreviated name of the logging component that issued the message or trace event. This is typically the class name for WebSphere internal components, but may be some other identifier for user applications.

LongName

The full name of the logging component that issued the message or trace event. This is typically the fully qualified class name for WebSphere internal components, but may be some other identifier for user applications.

EventType

A one character field that indicates the type of the message or trace event. Message types are in upper case. Possible values include:

A

An Audit message.

I

An Informational message.

W

A Warning message.

E

An Error message.

F

A Fatal message.

O

A message that was written directly to System.out by the user application or WebSphere internal components.

R

A message that was written directly to System.err by the user application or WebSphere internal components.

u

A special message type used by the message logging component of the WebSphere run time.

Z

A placeholder to indicate the type was not recognized.

ClassName

The class that issued the message or trace event.

MethodName

The method that issued the message or trace event.

Organization

The organization that owns the application that issued the message or trace event.

Product

The product that issued the message or trace event.

Component

The component within the product that issued the message or trace event.

UOW

The unit of work identifier for the event. This field is not currently used.

Basic format

Message events displayed in basic format use this format. The notation <name> indicates mandatory fields that are always displayed in the basic format message. The notation [name]indicates optional or conditional fields that is included if they can be determined.

TimeStampThreadIdShortNameEventType[ClassName][MethodName]message

Advanced format

Message events displayed in advanced format use this format. The notation <name> is used to indicate mandatory fields that are always displayed in the advanced format for message entries. The notation [name] is used to indicate optional or conditional fields that are included if they can be determined.

TimeStampThreadIdEventTypeUOWsource=LongName[ClassName]
[methodName]OrganizationProductComponentmessage