Suggestion

This trivial suggestion will improve the parsability of Tomcat's access log.

The Tomcat access log parsing format in server.xml is currently defined as

%a %{jira.request.id}r %{jira.request.username}r %t "%m %U%{sanitized.query}r %H" %s %b %D "%{sanitized.referer}r" "%{User-Agent}i" "%{jira.request.assession.id}r"

%t, representing the thread name, is not wrapped in quotes.

This is a problem because when Thread Diagnostics or Thready Plugin is enabled, spaces are included in the thread name. Spaces are a delimiter for this log format, so parsing this log can return consistent results depending on if the thread name contained a space. This include's Atlassian Support's own Stantler tool.

Suggested solution

Modify the server.xml as follows

%a %{jira.request.id}r %{jira.request.username}r "%t" "%m %U%{sanitized.query}r %H" %s %b %D "%{sanitized.referer}r" "%{User-Agent}i" "%{jira.request.assession.id}r"