Issue

Jenkins experiences a performance degradation or hangs.

Analysis of the thread-dump.txt or slow request files from a Support Bundle, or full thread dumps generated by collectPerformanceData.sh (Linux), or getThreadDumps.bat (Windows) shows one or more threads with a thread stack in socketRead() to an external resource as shown in the following snippets:

16019msec elapsed in Handling GET /jenkins/job/xxxxxxx/xxxxx/ from xx.xxx.xx.xxx
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
java.net.SocketInputStream.read(SocketInputStream.java:171)
java.net.SocketInputStream.read(SocketInputStream.java:141)

"Connecting to ldap://xx.xxx.xxx:xxxx/ : Handling GET / from xxx.xx.xx.xxx" 
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:170)
at java.net.SocketInputStream.read(SocketInputStream.java:141)

Resolution

The issue is not caused by Jenkins. The specific external resource that Jenkins is expecting a response from should be investigated to confirm that it responds to the request in an acceptable amount of time.