Using JIRA Remote Copy Plug-in results in heap exhaustion and full GC

Issue Summary

Using JIRA Remote Copy Plug-in results in heap exhaustion and full GC when using Jira version 8.1.0 and plugin version 6.0.0.

This does NOT occur in Jira v7.6.7 with plugin version 5.1.0.

Environment

• JAC
• JAC stg 

Steps to Reproduce

1. Navigate to an issue.
2. Select More in menu.
3. Select Remote Copy
4. Select a project.
5. Continue through the wizard to copy an issue, press next.
6. Wait 20-30 seconds while the JVM exhausts heap space and a full GC will be triggered. The copy fails and returns to a "copy issue" screen with an alert message:

   "The issue can be copied, but there are problems with some fields. Please check the list below"

1. Review Jira GC logs to confirm. I'm including screenshots of GC activity.

Expected Results

Plugin copies issue from one Jira service to another Jira service.

Actual Results

Issues do not appear to be copied. Heap exhausted triggering full GC.
See attachments.
 

Workaround

Currently there is no known workaround for this behavior other than disabling the plugin.