[JENKINS-28389] java.lang.ClassCastException: hudson.slaves.SlaveComputer cannot be cast to hudson.slaves.AbstractCloudComputer

[NotMyFault]

Hi,

I have configured a cloud (Bracket) VM as jenkins slave and while trying to save configuration, I am getting the following error. Configurations are getting saved but this exception is somehow discouraging.

Attached the exception which I am getting. Note that I have gone through the historic bugs/issues of Jenkins and couldn't find it so created one.

---

Originally reported by praveen528, imported from: java.lang.ClassCastException: hudson.slaves.SlaveComputer cannot be cast to hudson.slaves.AbstractCloudComputer

• status: Open
• priority: Major
• resolution: Unresolved
• imported: 2022-10-20

[NotMyFault]

pablaasmo:

I seem to have the same error, bit with a different stacktrace

SEVERE: Failed to initialize Jenkins
hudson.util.HudsonFailedToLoad: java.lang.ClassCastException: hudson.slaves.SlaveComputer cannot be cast to hudson.slaves.AbstractCloudComputer
at hudson.WebAppMain$3.run(WebAppMain.java:237)
Caused by: java.lang.ClassCastException: hudson.slaves.SlaveComputer cannot be cast to hudson.slaves.AbstractCloudComputer
at com.nirima.jenkins.plugins.docker.strategy.DockerOnceRetentionStrategy.start(DockerOnceRetentionStrategy.java:29)
at hudson.model.AbstractCIBase.updateComputer(AbstractCIBase.java:129)
at hudson.model.AbstractCIBase.updateComputerList(AbstractCIBase.java:180)
at jenkins.model.Jenkins.updateComputerList(Jenkins.java:1218)
at jenkins.model.Jenkins.(Jenkins.java:850)
at hudson.model.Hudson.(Hudson.java:83)
at hudson.model.Hudson.(Hudson.java:79)
at hudson.WebAppMain$3.run(WebAppMain.java:225)

I am not able to start jenkins properly

OS: RHEL 6.6
Jenkins: 1.596.2
Java: 1.7.0_79

[NotMyFault]

pablaasmo:

Tried to upgrade to jenkins 1.609.1, but have the same problem.

[NotMyFault]

pablaasmo:

Disabling the docker-plugin enabled me to start jenkins again.
I am not sure if this is related to this bug?
I will try installing a older version of the plugin that has worked before.

[NotMyFault]

pablaasmo:

After updating all plugins and restarted, I enabled docker-plugin 0.9.0.rc1 (the failed one was 0.9.0) and restarted.

Now everything runs as normal.
Go figure?
The 0.9.0 changelog says "Fix idleMinutes shadowing for DockerOnceRetentionStrategy", that might have something to do with it in my setup?

[NotMyFault]

adamyao:

I have a similar issue when trying to configure a cloud VM as slave and get the following error:

java.lang.ClassCastException: hudson.slaves.SlaveComputer cannot be cast to hudson.slaves.AbstractCloudComputer at com.nirima.jenkins.plugins.docker.strategy.DockerOnceRetentionStrategy.start(DockerOnceRetentionStrategy.java:24) at hudson.model.AbstractCIBase.updateComputer(AbstractCIBase.java:133) at hudson.model.AbstractCIBase.access$000(AbstractCIBase.java:45) at hudson.model.AbstractCIBase$2.run(AbstractCIBase.java:192) at hudson.model.Queue._withLock(Queue.java:1342) at hudson.model.Queue.withLock(Queue.java:1219) at hudson.model.AbstractCIBase.updateComputerList(AbstractCIBase.java:175) at jenkins.model.Jenkins.updateComputerList(Jenkins.java:1573) at jenkins.model.Nodes$8.run(Nodes.java:333) at hudson.model.Queue._withLock(Queue.java:1342) at hudson.model.Queue.withLock(Queue.java:1219) at jenkins.model.Nodes.load(Nodes.java:324) at jenkins.model.Jenkins$16.run(Jenkins.java:3091) at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:169) at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:282) at jenkins.model.Jenkins$7.runTask(Jenkins.java:1090) at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:210) at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:117) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) Caused: org.jvnet.hudson.reactor.ReactorException at org.jvnet.hudson.reactor.Reactor.execute(Reactor.java:269) at jenkins.InitReactorRunner.run(InitReactorRunner.java:47) at jenkins.model.Jenkins.executeReactor(Jenkins.java:1124) at jenkins.model.Jenkins.(Jenkins.java:929) at hudson.model.Hudson.(Hudson.java:86) at hudson.model.Hudson.(Hudson.java:82) at hudson.WebAppMain$3.run(WebAppMain.java:235) Caused: hudson.util.HudsonFailedToLoad at hudson.WebAppMain$3.run(WebAppMain.java:252)

even worse, I tried to rebounce the jenkins server and got the same error. Now I can not restart jenkins server anymore. Glad that it is on my local test environment.

OS: centos:7

jenkins server: 2.69

[NotMyFault]

melmbl:

Hi Adam, how did you solve this issue? we have the same problem with Jenkins master in production.