Used in: coherence.


The following table describes the elements you can define within the logging-config element.

Element Required/Optional Description
<destination> Required Specifies the output device used by the logging system.

Legal values are:

a file name

Default value is stderr.

If jdk is specified as the destination, Coherence must be run using JDK 1.4 or later; likewise, if log4j is specified, the Log4j libraries must be in the classpath. In both cases, the appropriate logging configuration mechanism (system properties, property files, etc.) should be used to configure the JDK/Log4j logging libraries.

Preconfigured override is tangosol.coherence.log
<severity-level> Required Specifies which logged messages will be output to the log destination.

Legal values are:

0     - only output without a logging severity level specified will be logged
1     - all the above plus errors
2     - all the above plus warnings
3     - all the above plus informational messages
4-9 - all the above plus internal debugging messages (the higher the number, the more the messages)
-1   - no messages

Default value is 3.

Preconfigured override is tangosol.coherence.log.level
<message-format> Required Specifies how messages that have a logging level specified will be formatted before passing them to the log destination.

The value of the message-format element is static text with the following replaceable parameters:

{date}      - the date/time format (to a millisecond) at which the message was logged
{version} - the Tangosol Coherence exact version and build details
{level}    - the logging severity level of the message
{thread}   - the thread name that logged the message
{member}   - the cluster member id (if the cluster is currently running)
{text}      - the text of the message

Default value is:

{date} Tangosol Coherence {version} <{level}> (thread={thread}, member={member}): {text}
<character-limit> Required Specifies the maximum number of characters that the logger daemon will process from the message queue before discarding all remaining messages in the queue. Note that the message that caused the total number of characters to exceed the maximum will NOT be truncated, and all messages that are discarded will be summarized by the logging system with a single log entry detailing the number of messages that were discarded and their total size. The truncation of the logging is only temporary, since once the queue is processed (emptied), the logger is reset so that subsequent messages will be logged.

The purpose of this setting is to avoid a situation where logging can itself prevent recovery from a failing condition. For example, with tight timings, logging can actually change the timings, causing more failures and probably more logging, which becomes a vicious cycle. A limit on the logging being done at any one point in time is a "pressure valve" that prevents such a vicious cycle from occurring. Note that logging occurs on a dedicated low-priority thread to even further reduce its impact on the critical portions of the system.

Legal values are positive integers or zero. Zero implies no limit.

Default value is 4096.

Preconfigured override is tangosol.coherence.log.limit

The content override attribute xml-override can be optionally used to fully or partially override the contents of this element with XML document that is external to the base document.