Issues updated or created on one node while another node is performing a re-index do not get indexed

Issues created on other nodes while one node is performing a foreground re-index will ultimately be lost from the index after the re-index operation is complete.

Steps to Reproduce

1. Setup a JDC environment with at least 2 nodes
2. Remove one of the nodes from the load balancer (so it is not accessible by normal users)
3. Initiate a foreground re-index on the node you removed from the load balancer
4. While the foreground re-index is in progress, create and update several issues on the other nodes(s) which are still in the load balancer and available to users
5. Wait for the foreground re-index to complete, and for the new index to be completely replicated to all other nodes in the cluster
6. Use the Issue Navigator (in List Mode, so it displays information from the index) to search for the issues you created and updated, and observe:
   1. Whether or not the issues appear in the search results
   2. What the last updated date/time is
   3. If the updates you made are reflected in the search results

Workaround

Run a full reindex during an outage window, and offline all of the other nodes while it runs, to prevent any possibility this will be encountered.