Performance degrade with many calls to com.day.crx.persistence.tar.index.IndexFile.getEntry

Symptoms

• Profiling or thread dumps show many calls to com.day.crx.persistence.tar.index.IndexFile.getEntry
• Listing of files under version workspace reveals presence of many tar index files (usually they are less than 5 tar index files)
  

Cause

When tar files are manually optimized using CRX console or custom script by creating optimize.tar, the tar index files are not merged automatically

Analysis / Resolution

On analysis of the results of profiling tool and thread dumps, it shows many calls to com.day.crx.persistence.tar.index.IndexFile.getEntry

When we manually perform tarpm optimization then 'index merging of tar files' is not performed. This needs to be done separately using CRX console or can be automated using wget/curl. It is located here: 

http://<host>:<port>/crx/config/tarpm_indexmerge.jsp

Recommendations

• Trigger tar index merge on a regular basis, or when it reaches a certain threshold (eg. 20 tar index files). You can create a simple monitoring which will notify in case of significant increase of index files with threshold specified.
• Automatic, scheduled Tar PM optimization does include an index merge: at the very
  beginning of the scheduled optimization, and at the very end. Therefore, in case of manual tarpm optimization, it is recommended to schedule the index merge of tar files before and after tarpm optimization.
  

Applies

CRX1.4.x, CRX2.x