Logging supports
viewing, tracing, and troubleshooting
the runtime behavior of an application. Java Persistence
API (JPA) provides a flexible logging system that is integrated with
the application server to assist you in troubleshooting problems.
About this task
Logging channels Attention: Logging
can have a negative impact on performance. Limit or disable logging
when you run any performance tests.
New feature: This topic
references one or more of the application server log files. Beginning
in WebSphere Application Server Version 8.0 you can configure the
server to use the High Performance Extensible Logging (HPEL) log and
trace infrastructure instead of using
SystemOut.log ,
SystemErr.log,
trace.log,
and
activity.log files or native z/OS logging
facilities. If you are using HPEL, you can access all of your log
and trace information using the LogViewer command-line tool from your
server profile bin directory. See the information about using HPEL
to troubleshoot applications for more information on using HPEL.
newfeat
In additional
to the channels used by OpenJPA, a trace group named openjpa enables
channels that are prefixed with “openjpa.” Specifying “openjpa” for
a trace group overrides any other trace group specification that is
specific to a channel; for example:
openjpa.Runtime=debug:openjpa.jdbc.SQL=all
openjpa=all
Avoid trouble: The openjpa.Log property is ignored
if it is defined in a container-managed persistence unit that uses
the persistence providers that are provided with the application server.
In this case, you must use the standard trace specification for the
application server.
gotcha
OpenJPA and JPA for WebSphere
® Application Server
implement logging channels to which message data, trace data, and
debugging data can be recorded to a configurable repository. The JPA
component creates the logging channel at run time and assigns a channel
name for identification. The component writes information to the configured
repository through the channel. OpenJPA and JPA for WebSphere Application Server create the
following channels:
- openjpa.Tools - Command line and
Ant server tools
- openjpa.MetaData - Metadata information
- openjpa.Enhance - Enhancement and runtime class generation
- openjpa.Runtime - Messages generated during run time
- openjpa.Query -
Query information
- openjpa.DataCache - L2 data cache
plug-in information
- openjpa.jdbc.JDBC - JDBC connection
information
- openjpa.jdbc.SQL- Detailed SQL execution
statements and
information
- openjpa.jdbc.SQLDiag- Additional SQL diagnostic
information
for the entity operations create, retrieve, update, and delete.
- openjpa.jdbc.Schema-
Details about operations on the database
schema
- wsjpa.pdq- Trace of all interactions between
store manager
and PDQ run time
- wsjpa.Sqlgen-
Diagnostic trace for
wsdbgen program
Logging levels
Each of
the logging channels
use logging levels to control which messages are recorded. The following
logging levels are supported by the JPA architecture:
- TRACE -
the most detailed option
- INFO - information related
to the specific channel
- WARN - warning messages
- ERROR -
error condition messages
- FATAL - fatal condition messages
By using a particular logging channel together with logging levels,
you can control the types of logging messages and the amount of logging
messages that are recorded.
Supported configurations: These logging
functions apply only to OpenJPA and JPA for the application server.
Logging functions that are provided in implementations of a third-party
persistence provider are not covered. However, if the logging output
from a third-party persistence provider is directed to the Java
System.out or
System.err file
output streams, the messages are handled by the environment accordingly
at run time.
sptcfg
Logging in the application server
The
default JPA persistence provider that is supported by the application
server records messages and tracing data that are automatically integrated
into the RAS component. Alternatively, OpenJPA implements a custom
logger to route messages from OpenJPA channels to the channels of
the application server.
The channel names that are supported
by OpenJPA are used as the trace group names in the trace level for
the application server. The mappings of OpenJPA logging levels to
trace levels in the application server are:
Table 1. Mapping
OpenJPA logging levels to application server trace levels. The
mappings of OpenJPA logging levels to trace levels in the application
server are:
OpenJPA
logging level |
Trace level
for the application
server |
TRACE |
debug |
INFO |
info |
WARN |
warning |
ERROR |
error |
FATAL |
fatal |
Logging in a client container and
standalone Java application
OpenJPA
logging uses the basic logging framework and output format:
millis [persistence-unit name]level[thread identifier] channel - message
.
Important: When using IBM® Optim PureQuery Run time, the PDQ
store manager also uses JDBC in some situations, such as for large
result set processing. When tracing all calls to the database, you
must trace both JDBC and PDQ.
Example: property name=”wsjpa.Log” value=”SQL=TRACE”/
This
traces the SQL and input parameter values.
property name=”wsjpa.Log” value=”pdq=TRACE, JDBC=TRACE”/
This
performs a detailed trace of calls to the IBM Optim PureQuery
Runtime and any calls to JDBC. If you are using pureQuery and must
trace calls to the database, you must perform both traces.
The
default logging system accepts the following parameters:
- File:
The name of the file to which the application server
logs information. You can also use standard output stdout or
standard error stderr to send messages. By default, JPA sends
log messages to standard error.
- DefaultLevel: The default
logging level for channels that
are not configured. The values can be TRACE, INFO, WARN,
and ERROR. The default setting is INFO.
- DiagnosticContext:
A string that is placed at the beginning
of all log messages. If a DiagnosticContext is not supplied and an
openjpa.Id property is available, the openjpa.Id value is used.
- <channel>:
The channel that is being
logged. This parameter can be used to configure the logging level
of the channel.