Steps to reproduce:

1. Install a new version of JAG in an environment where no JAG was installed before.
2. Go to "Indexing" in JIRA.
3. Run a full re-index or a background re-index

Expected behaviour: You should be informed that lexorank indexer is running and running a full re-index at the same time will slow the performance.

When a full re-index or background re-index runs immediately after installing JAG you are going to see how the time and performance of the app degrades because it takes twice the time to do everything.

2 threads are doing the same work at the same time.

Work around

If you want to migrate from JIRA Agile < 6.4 to JIRA Agile >= 6.4.5, and you want to avoid a background re-index being triggered by JIRA Agile's upgrade task GhUpgradeTask044, you can set the Java System Property upgrade.reindex.allowed to false.

Notes

This issue only tracks the scenario when the first population/migration of rank values is happening in JIRA Agile after installing JIRA Agile >= 6.4. We have tracked (and resolved) a separate issue around not letting balancing and foreground re-indexes happen at the same time (the re-index cancels any balancing jobs until it is done).