JCMA may not migrate some comments

Issue Summary

In some cases, when migrating projects from Jira Server to Jira Cloud, you may notice a few issues missing comments, the project migration won't fail, however, you will be able to find an error on the server logs.

Steps to Reproduce

1. Migrate projects from Jira Server to Cloud
2. Validate the comments on the issues.

Expected Results

All the comments get migrated.

Actual Results

In some cases, we haven't been able to pinpoint exactly why this happens, you may notice a few missing comments on the issues.

The below exception is thrown in the atlassian-jira.log file:

ERROR projectkey project-import We couldn't import Comment
id (on Issue issuekey by 'Username' on 2019-11-22T22:46:40Z).
Reason: QueryException: Caught BatchUpdateException for insert into
"public"."jiraaction" ("issueid", "author", "actiontype",
"actionlevel", "rolelevel", "actionbody", "created", "updateauthor",
"updated", "actionnum", "tokens", "actionbody_adf",
"actionbody_adf_id", "actionbody_adf_version")

Workaround

Export the issues with the missing comments from your Jira Server, in the CSV format import back in the Cloud, you should only need the issue key, summary and the comments to update the missing comments on the Cloud.