Reducing file store file sizes

It is possible to reduce the sizes of the log file and store files in the configuration. However, such reduction is only possible when certain conditions are met.

Reducing the file sizes can be difficult in practice due to the following reasons:

1. It is not possible to shrink the files smaller than the amount of space that their contents currently consume.

2. There is no support for compaction of the contents of the permanent store file and temporary store file so fragmentation might keep these store files artificially large. As such, when the values of the file sizes in the configuration are reduced and the messaging engine restarted, it might not be possible to change the sizes of the files to the required values.

When this situation occurs, the messaging engine emits warning messages to SystemOut.log and continues to use the existing values. It attempts to apply the configuration changes repeatedly each time it starts until it succeeds.

IBM recommends using the High Performance Extensible Logging (HPEL) log and trace infrastructure . We view HPEL log and trace information using the logViewer .

Problems might also arise when the file store file sizes are set too small.

Use High Performance Extensible Logging to troubleshoot applications