This information applies to both coupling facility and DASD-only
log streams. damaged when it cannot recover log data from either DASD
staging data sets or the local storage buffers after a system, sysplex,
or coupling facility failure. Applications are notified of the damage
by the following means:
- When they issue IXGCONN, they receive return code, X'04',
reason code, IXGRsnCodePossibleLossOfData
- When they issue IXGBRWSE, they receive return code, X'04',
reason code, IXGRsnCodeWarningGap
- Their listen exit detects ENF event
48.
Applications should do the following to respond to a damaged log
stream condition, depending on how critical a data loss is to the
application:
- Applications that absolutely cannot tolerate any data loss whatsoever,
some short term transaction logs for example, should stop issuing
system logger services to the affected log stream, disconnect from
the log stream, perform recovery for the application, and then reconnect
to a new log stream.
- Applications that can tolerate some data loss, such as archive
logs that do not read a great deal of data from the log stream, may
be able to continue using the log stream. See How system logger handles gaps in the log stream for
a summary of the results of reading a damaged log stream.