1.3 Logger exploiters

 < Day Day Up > 



1.3 Logger exploiters

The System Logger was first made available as part of MVS/ESA V5.2, and was initially used by Operlog, Logrec, and CICS, which used System Logger to replace its own log and journal files. Since then, as more products introduce sysplex exploitation support, the list of System Logger users has grown. The list now includes:

CICS

CICS use System Logger for its logs (DFHLOG, DFHSHUNT, and DFHLGLOG) and user journals. While each CICS region maintains its own logs, it is possible to create a merged forward recovery journal by specifying that all the CICS regions that update a given file write to the same forward recovery journal.

TVS

DFSMS Transactional VSAM Services for its logs (IGWLOG, IGWSHUNT, and log-of-logs). While each TVS subsystem maintains its set of Undo logs (LOG+SHUNT), it is possible to have the log-of-log log stream and the forward recovery log streams shared with the CICS systems.

IMS

The IMS Shared Message Queue facility uses System Logger to log data created as messages are processed from the shared message queue. The log data is only subsequently required if it becomes necessary to recover either of the Shared Message Queue structures.

RRS

The MVS Resource Recovery Services component of z/OS has a number of different types of log data (up to five), and it uses System Logger to store and manage this data in a manner that allows the data to be accessed from any system in the sysplex.

APPC

To provide resource recovery for protected conversations, APPC/MVS requires the names of local and partner LU logs, and the negotiated syncpoint capabilities for each local/partner LU pair. This information needs to be available and accurate for successful resynchronization after a failure. To store this information, APPC/MVS uses a System Logger log stream.

Merged Logrec

In a Parallel Sysplex environment, it is possible to have the systems write any Logrec records to a single merged log stream.

OPERLOG

In a Parallel Sysplex environment, you can create a sysplex-wide view of the syslog activities by writing syslog records to a single merged log stream. This provides a view of activity at the sysplex level, which is invaluable when trying to debug multi-system problems.

SA/390

System Automation for OS/390 can write two types of data to a log stream. The first of these is messages produced by the z/OS HealthChecker component of SA/390. The other is produced by the Automation Manager and it is organized across two log streams: the workitem and the message log.

WebSphere

WebSphere Application Server uses a log stream to writes error messages. You can have a log stream per each cloned server or a shared log stream shared across multiple instances of servers.



 < Day Day Up > 



Systems Programmer's Guide to--Z. OS System Logger
ASP.NET for Web Designers
ISBN: 738489433
EAN: 2147483647
Year: 2002
Pages: 99
Authors: Peter Ladka

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net