Do not rely on Online Compaction in AEM 6.x


Most of you should probably already be aware that there are some challenges in AEM 6.x with repository disk growth. While this has improved marginally in more recent releases, it’s absolutely vital to a healthy Adobe Experience Manager stack that offline compaction be performed regularly. For our Managed Services clients, this is a service our Systems Engineers take care of, including watching the growth rates and knowing what kind of schedule a given environment needs.

Old hat, right? Everyone knew about this? Great. However, there is one piece you MAY NOT know about that we feel it’s important to notify people of.

Within Adobe Experience Manager itself, there is a JMX agent that implies online compaction is available. In fact, you might find some people using this in conjunction with the occasional offline compaction; however, Adobe has stated that this “online compaction” is unsupported:

Q: What is the supported way of performing revision cleanup?

A: Offline revision cleanup is the only supported way of performing revision cleanup*. Online revision cleanup is present in AEM 6.2 under restricted support.”

This phrase “restricted support” is defined in the AEM documentation to have the following meaning:
“To ensure our customers project success, Adobe provides full support within a restricted support program, which requires that specific conditions are met. R-level support requires a formal customer request and confirmation by Adobe. For more informations, please contact Adobe Customer Care.”

From experience, we have found that online compaction will not fully compact the store, and sometimes has been know to corrupt the data store. Although the JMX agent can still be found in Adobe Experience Manager, until Adobe has adjusted their position on it, we would recommend against using this on your production instances.


*emphasis mine