Jenkis CLI client connection problem over CLI-Port

[Łukasz Zachulski]

Hello,

I'm using Jenkins 1.642.1 and since 2 weeks I'm seeing recurring problems with Jenkins CLI client.
Precisely the problem is with CLI client not able to correctly establish connection with Jenkins master and get an response. It looks like the connection hangs.

Checking connections with `netstat` I can noticed that clients can establish connection.

# netstat -an  | grep 47207
10.21.18.38.47207    10.21.16.206.32910   14720      0 49209      0 CLOSE_WAIT         <--- cli already finished running
      *.47207              *.*                0      0 49152      0 LISTEN
10.21.18.38.47207    10.21.16.200.45514   49640      0 49617      0 ESTABLISHED        <--- hanging cli connection

However what bother me is the single one connection which is in CLOSE_WAIT state. CLI client which initialized this connection already exit, but for some reason Jenkins master can't close the socket.

Right now the only workarounds that works for me is:
- reset CLI-Port or
- restart Jenkins master

Any idea what going on? And is there a solution or better workaround?


ps. Jenkins and CLI client have been working perfectly well for over a 1,5 years. During that time we haven't change Jenkins version or its plug-ins.

Cheers,
Lukasz.

[Łukasz Zachulski]

Is there a way to pinpoint the thread which holds CLOSE_WAIT connection?