When clicking on build, it looks like nothing is happening: the build does not appear in the Jenkins Queue.
This kind of symptoms mean that something is holding a lock on the Jenkins Queue.
You can verify that you are experiencing a Deadlock by going into
You should see several threads mentioning
In case you encounter a case like that, it is best to open a case with CloudBees Support. For such a case, CloudBees Support will need the data as indicated in this KB article (Linux) or this one (Windows).
Here is a list of known plugins affected to the issue. This list is not exhaustive:
The Docker Plugin prior to 1.0.0
The Anka Build Plugin: no known fix currently exist at the latest version (2.2.0). In case you encounter the issue, the best approach is to either fix the connectivity issue with the Anka cloud, or delete the cloud configuration in Jenkins.
In case you would like to investigate the issue yourself, you should look into the thread dump for a stack having a lock on the Jenkins Queue and performing long operation. For instance the following dump exhibits the issue:
at java.net.SocketInputStream.socketRead0(Native Method) <--- socket operation // suppressed for clarity at com.nirima.jenkins.plugins.docker.strategy.DockerOnceRetentionStrategy$1$1.run(DockerOnceRetentionStrategy.java:112) at hudson.model.Queue._withLock(Queue.java:1320) at hudson.model.Queue.withLock(Queue.java:1197) <--- Lock on the Queue at com.nirima.jenkins.plugins.docker.strategy.DockerOnceRetentionStrategy$1.run(DockerOnceRetentionStrategy.java:106) <--- docker plugin // suppressed for clarity
NB: you should take several thread dumps to ensure there is a lock, one single thread dump showing the previous stack is perfectly normal.