要約

Collaborative Editing (CE) stops working in Confluence and we see the following message in atlassian-synchrony.log files 

DEBUG [604:StdOutHandler [E:\Confluence_Install_Directory\Confluence\jre\bin\java.exe]] 2021-02-02 20:23:00,399 WARN [Thread-8] [synchrony.server.watch-pid] PID 3060 has died. Terminating

There are no error messages or warning before the above log line.

環境

The issue is known to happen in Microsoft Windows environment with CE enabled.

診断

Synchrony keeps on checking for process of Confluence and terminates itself when it can't find Confluence's PID. The log message states that Synchrony has been looking for process ID of Confluence (3060 in above log snippet) and can't find it. So, as a result the process of Synchrony dies. 

Synchrony looks for PID of Confluence via tasklist.exe. In some versions of MS Windows tasklist doesn't work properly and returns Out Of Memory errors.

A simple script like follows can be used to check whether tasklist runs properly in OS or not.

while ($true) {
Get-Date >> taskList.txt
tasklist | findstr /i "java tomcat" >> taskList.txt
Start-Sleep -s 5
}

 The process of Confluence runs as tomcat and process of Synchrony as java

If the tasklist command errors out, Synchrony will keep on terminating (because it thinks that Confluence has died).

ソリューション

The root cause is primarily lack of proper functioning of the command tasklist.exe. So, work with Windows System admins to diagnose this issue further and apply proper patches/updates in Windows as necessary.