Hi,

We've been tasked for upgrading jenkins from 2.254 to 2.346.1 . We've done this steps for test purpose;

We created a new environment  from scratch on ubuntu server. We copied our plugin folder to this environment and started jenkins. After than we install 2.346.1 with apt update command and after saw that jenkins is up and running we upgraded all plugins and restarted jenkins for several times. Now there is no available update for plugins and all plugins are seems enabled. But we have several problems.;

First;

We couldn't see any logs on /var/logs/jenkins/jenkins.log file we only see 

Running from: /usr/share/java/jenkins.war 

line and that's all (we configured jenkins.service file also for storing logs to /var/log/jenkins/jenkins.log with enabling the line)

Second: Configure system  settings can not be saved. When we are trying to update a settings or jobs or trying to add Credentials Jenkins is to a plugin like Sonarqube or Testinium or TFVC is too slow retrieving credentials sometime couldn't find credentials and after finding credentials and try to save it gives an Errors like ERR_EMPTY_RESPONSE or

OOPS! A problem occured  while processing request : Logging ID: <SomeString>

Before we done this upgrade we also try to upgrade to the version 2.332 and we didn't have problem with log files as far as we remember. So Are we missing something about logging level and upgrade steps?

Although we didn't copy the jenkins home folder this environments doesn't seem stable.

Thanks in advance.