Performance degradation due to a high number of requests to the table propertyentry

Summary

After upgrade to Jira 7.6.4 customers with 10k+ users see major performance degradation. Jira is hitting propertyentry table up to 10x times more causing DB overload. 
Problem is amplified in correlation with another issue - JRASERVER-65168.

Environment

• Jira 7.6.4/7.6.5 (please note that only these versions are affected from 7.6 branch) or other Affected versions

Expected Results

The number of requests to the propertyentry table is the same as before.

Actual Results

The number of requests to the propertyentry table increased 10 times.

Notes

Root cause

As part of a fix for JRASERVER-67041 users attributes cache was switched to short leaving one to eliminate the need for cluster cache replication. Some features like user picker or Jira service desk iterate many users' attributes entries and as a result DB load is increased significantly as user attributes cache is usually empty. 

Workaround

Set system property to revert the changes (code will work as pre-7.6.4):

• add to JVM_SUPPORT_RECOMMENDED_ARGS:

  -Djira.cache.CachingOfBizPropertyEntityStore.ApplicationUser.remote=true