JIRA uses excessive amount of memory during issue export

Summary

JIRA caches different data in JiraAuthenticationContextImpl and RequestCacheController for each request in ThreadLocal. That data is cleared after each request so there is no problem there, but during large issue export that data can stay around for a long time causing high memory pressure and later high GC pressure.

Environment

• JIRA instance with 1M+ issue

Steps to Reproduce

1. Access the issue navigator and search for large number of issues
2. Export these issues to Excel/CSV/XML

Expected Results

Application streams the data and uses reasonable amount of memory (~100M)

Actual Results

Application caches some data for the duration of the whole request. In some case it can be 2GB+ data, which might cause OOM

Notes

Example of Dominator tree from heap dump after OOM

Objects details

• Thread ajp-nio-8009-exec-819 - 5GB

  Class Name                                                                                          | Shallow Heap | Retained Heap | Percentage
  ------------------------------------------------------------------------------------------------------------------------------------------------
  org.apache.tomcat.util.threads.TaskThread @ 0x132e509ba8  ajp-nio-8009-exec-819 Native Stack, Thread|          136 | 5,324,618,224 |     30.18%
  |- java.lang.ThreadLocal$ThreadLocalMap @ 0x136e5f3528                                              |           24 | 5,213,775,632 |     29.55%
  |  '- java.lang.ThreadLocal$ThreadLocalMap$Entry[2048] @ 0x14f984b088                               |        8,208 | 5,213,775,608 |     29.55%
  |     |- java.lang.ThreadLocal$ThreadLocalMap$Entry @ 0x12b2acec98                                  |           32 | 2,967,537,480 |     16.82%
  |     |- java.lang.ThreadLocal$ThreadLocalMap$Entry @ 0x12b2acec48                                  |           32 | 2,245,747,520 |     12.73%
  |     |- java.lang.ThreadLocal$ThreadLocalMap$Entry @ 0x135da74120                                  |           32 |        83,272 |      0.00%
  

  Note two large ThreadLocals: 2.9GB and 2.2GB
  requestUrl - /sr/jira.issueviews:searchrequest-excel-all-fields/temp/SearchRequest.xls with empty queryString

Workaround

Problem is largely mitigated by the following

• limiting search results export, see JRASERVER-63239
• Limiting Custom Field Value cache, see JRASERVER-68806
• Addition option to limit RequestCachingGroupManager, see JRASERVER-69733