When you’re working with messages that are backed off to eh filesystem, then you may see find that there are a bunch of files that will be written to your tempdir (either configured explicitly or the value of java.io.tmpdir). They will be auto-deleted when messages go out of scope, and garbage collection happens. This will be particularly apparent if your configuration contains a large-message-workflow with a large-fs-consumer; you will find that the original file is left on the filesystem until garbage collection occurs which may be long after any processing has completed.
Since you can’t guarantee when garbage collection happens, if you want to periodically force the adapter to suggest a System.gc(), and cleanup any temporary files, we can do this with a custom channel. Essentially your custom channel needs to have a file-system consumer on your temporary directory (denoted here as ${adapter.temp.dir} or ${adapter.temp.dir.url}) and a jmx connection to itself so we end up with something like this.
<channel>
<unique-id>Cleanup</unique-id>
<auto-start>true</auto-start>
<workflow-list>
<!-- Clean up temp folder -->
<large-message-workflow>
<unique-id>CleanupTempFiles(large)</unique-id>
<consumer class="large-fs-consumer">
<message-factory class="file-backed-message-factory">
<temp-directory>${adapter.temp.dir}</temp-directory>
<create-temp-dir>true</create-temp-dir>
</message-factory>
<destination class="configured-consume-destination">
<destination>${adapter.temp.dir.url}</destination>
<filter-expression>OlderThan=-P1D__@@__SizeGTE=1024000</filter-expression>
<configured-thread-name>CleanupTempFiles(large)</configured-thread-name>
</destination>
<create-dirs>true</create-dirs>
<file-filter-imp>com.adaptris.core.fs.CompositeFileFilter</file-filter-imp>
<reacquire-lock-between-messages>true</reacquire-lock-between-messages>
<poller class="quartz-cron-poller">
<cron-expression>0 */15 * * * ?</cron-expression>
</poller>
<wip-suffix>_safe_to_delete</wip-suffix>
<reset-wip-files>true</reset-wip-files>
</consumer>
<service-collection class="service-list"/>
<send-events>false</send-events>
</large-message-workflow>
<!-- Clean up temp folder -->
<standard-workflow>
<unique-id>CleanupTempFiles(small)</unique-id>
<consumer class="fs-consumer">
<destination class="configured-consume-destination">
<destination>${adapter.temp.dir.url}</destination>
<filter-expression>OlderThan=-P1D__@@__SizeLT=1024000</filter-expression>
<configured-thread-name>CleanupTempFiles(small)</configured-thread-name>
</destination>
<create-dirs>true</create-dirs>
<file-filter-imp>com.adaptris.core.fs.CompositeFileFilter</file-filter-imp>
<reacquire-lock-between-messages>true</reacquire-lock-between-messages>
<poller class="quartz-cron-poller">
<cron-expression>0 */15 * * * ?</cron-expression>
</poller>
<wip-suffix>_safe_to_delete</wip-suffix>
</consumer>
<service-collection class="service-list"/>
<send-events>false</send-events>
</standard-workflow>
<!-- Do some Garbage Collection -->
<standard-workflow>
<unique-id>GarbageCollection</unique-id>
<consumer class="polling-trigger">
<destination class="configured-consume-destination">
<configured-thread-name>GarbageCollection</configured-thread-name>
<destination>GarbageCollection</destination>
</destination>
<poller class="quartz-cron-poller">
<cron-expression>0 */12 * * * ?</cron-expression>
</poller>
</consumer>
<service-collection class="service-list">
<services>
<jmx-operation-call-service>
<connection class="jmx-connection">
<jmx-service-url>service:jmx:jmxmp://localhost:5555</jmx-service-url>
</connection>
<object-name>java.lang:type=Memory</object-name>
<operation-name>gc</operation-name>
</jmx-operation-call-service>
</services>
</service-collection>
<send-events>false</send-events>
</standard-workflow>
</workflow-list>
</channel>
Once this channel is started; the following things happen (the scheduling is arbitrary, as is the size filter):
- Every 15 minutes we consume files smaller than ~10Mb from your temp directory where the last modified time is at least 1 day ago.
- Every 15 minutes we consume files larger than (or equal to) ~10Mb from your temp directory where the last modified time is at least 1 day ago.
- If garbage collection happens then they will be deleted; if not, then we will request a gc in the next workflow.
- Every 12 minutes we connect to ourselves via JMX and issue a garbage collection request.
- Note that you can issue the JMX call manually via the UI, or using your preferred JMX application