How to Reduce CQ Disk I/O

By increasing the CRX Bundle Cache size, disk I/O (especially the I/O caused by READs) can be reduced.

This can be set in /crx-quickstart/repository/repository.xml It has to be set in /crx-quickstart/repository/workspaces/crx.default/workspace.xml as well.



The value is in MB (the default is 8 MB). 2048 means 2 GB.

Please note that setting consistencyCheck to “true” will increase the time CQ takes to start up - the more the number of CRX bundles, the longer it will take.

See the screenshot below for a CRX Bundle cache size of 2 GB (JVM heap was 8 GB, with about 2.4 million JCR nodes, and a 36 GB repository).



Command = iostat -x -k 5

At 50% CPU utilization on an 8 vCPU cloud instance, the READ IOPS (r/s) is 0, WRITE IOPS (w/s) is 1.2 and disk utilization (%util) is 0.4% for the EBS volume dm-0.

NOTE: A CRX content “bundle” is NOT the same as an OSGi Java code “bundle”.