Example - merging log data from across the sysplex

The scenario in Figure 1 shows a configuration where a transaction manager system logger application runs on two systems in a sysplex. The applications write and merge log data into one log stream, named TRANSLOG in this example. This configuration is the one you would set up for the OPERLOG or logrec log stream applications.

Figure 1. Example: Merging Log Data from Systems Across a Sysplex

Example of Merging Log Data from Systems Across a Sysplex

Some of the key points this example shows are:

Log data is written to the TRANSLOG log stream on a coupling facility list structure.
Multiple instances of a system logger application running on different systems to share data.
The TRANSLOG log stream is the only log stream occupying the coupling facility list structure.
System logger automatically moves the oldest log data from the coupling facility to DASD when the data hits the installation-defined thresholds for the coupling facility list structure for this log stream. From the point of view of the system logger application, it does not matter whether the log data resides on the coupling facility structure or on DASD.