[JENKINS-69380] Some pipeline break with ClassCastException after jenkins restart

Before the Jenkins restart about 300 pipeline where running.

4 of them did not survive the restart. In the Jenkins logs, I found the following Exception that relates to one of the affected pipelines:

```
2022-08-17 05:13:48.280+0000 [id=5356] WARNING o.j.p.w.cps.CpsFlowExecution#cleanUpHeap: failed to clean up memory from Owner[somePipeline/195:somePipeline #195]
java.lang.ClassCastException: class java.io.ObjectStreamClass$Caches$1 cannot be cast to class java.util.concurrent.ConcurrentMap (java.io.ObjectStreamClass$Caches$1 and java.util.concurrent.ConcurrentMap are in module java.base of loader 'bootstrap')
at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.cleanUpObjectStreamClassCaches(CpsFlowExecution.java:1426)
at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.cleanUpLoader(CpsFlowExecution.java:1321)
at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.cleanUpHeap(CpsFlowExecution.java:1287)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:444)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$400(CpsThreadGroup.java:96)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:312)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:276)
at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:67)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:139)
at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:829)

```

---
Originally reported by shoelzle, imported from: Some pipeline break with ClassCastException after jenkins restart

• status: Open
  
• priority: Minor
  
• component(s): workflow-cps-plugin
  
• resolution: Unresolved
  
• votes: 0
  
• watchers: 1
  
• imported: 2025-12-07
  

Raw content of original issue

Before the Jenkins restart about 300 pipeline where running.

4 of them did not survive the restart. In the Jenkins logs, I found the following Exception that relates to one of the affected pipelines:



2022-08-17 05:13:48.280+0000 [id=5356]	WARNING	o.j.p.w.cps.CpsFlowExecution#cleanUpHeap: failed to clean up memory from Owner[somePipeline/195:somePipeline #195]

java.lang.ClassCastException: class java.io.ObjectStreamClass$Caches$1 cannot be cast to class java.util.concurrent.ConcurrentMap (java.io.ObjectStreamClass$Caches$1 and java.util.concurrent.ConcurrentMap are in module java.base of loader 'bootstrap')

	at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.cleanUpObjectStreamClassCaches(CpsFlowExecution.java:1426)

	at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.cleanUpLoader(CpsFlowExecution.java:1321)

	at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.cleanUpHeap(CpsFlowExecution.java:1287)

	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:444)

	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$400(CpsThreadGroup.java:96)

	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:312)

	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:276)

	at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:67)

	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)

	at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:139)

	at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)

	at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:68)

	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)

	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)

	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)

	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)

	at java.base/java.lang.Thread.run(Thread.java:829)

environment

```
Jenkins: 2.318

plugins:

  ace-editor: "1.1"

  antisamy-markup-formatter: "2.4"

  apache-httpcomponents-client-4-api: "4.5.13-1.0"

  authentication-tokens: "1.4"

  authorize-project: "1.4.0"

  badge: "1.9"

  blueocean: "1.25.1"

  blueocean-autofavorite: "1.2.4"

  blueocean-bitbucket-pipeline: "1.25.1"

  blueocean-commons: "1.25.1"

  blueocean-config: "1.25.1"

  blueocean-core-js: "1.25.1"

  blueocean-dashboard: "1.25.1"

  blueocean-display-url: "2.4.1"

  blueocean-events: "1.25.1"

  blueocean-git-pipeline: "1.25.1"

  blueocean-github-pipeline: "1.25.1"

  blueocean-i18n: "1.25.1"

  blueocean-jwt: "1.25.1"

  blueocean-personalization: "1.25.1"

  blueocean-pipeline-api-impl: "1.25.1"

  blueocean-pipeline-editor: "1.25.1"

  blueocean-pipeline-scm-api: "1.25.1"

  blueocean-rest: "1.25.1"

  blueocean-rest-impl: "1.25.1"

  blueocean-web: "1.25.1"

  bootstrap4-api: "4.6.0-3"

  bootstrap5-api: "5.1.1-1"

  bouncycastle-api: "2.20"

  branch-api: "2.7.0"

  build-with-parameters: "1.6"

  caffeine-api: "2.9.2-29.v717aac953ff3"

  checks-api: "1.7.2"

  cloudbees-bitbucket-branch-source: "2.9.11"

  cloudbees-folder: "6.16"

  command-launcher: "1.2"

  conditional-buildstep: "1.4.1"

  configuration-as-code: "1.54"

  configuration-as-code-groovy: "1.1"

  credentials: "2.6.2"

  credentials-binding: "1.27"

  display-url-api: "2.3.5"

  durable-task: "1.39"

  echarts-api: "5.2.1-2"

  favorite: "2.3.3"

  font-awesome-api: "5.15.4-1"

  git: "4.9.0"

  git-client: "3.10.0"

  git-server: "1.10"

  github: "1.34.1"

  github-api: "1.133"

  github-branch-source: "2.11.3"

  handlebars: "3.0.8"

  handy-uri-templates-2-api: "2.1.8-1.0"

  htmlpublisher: "1.27"

  http_request: "1.11"

  jackson2-api: "2.13.0-230.v59243c64b0a5"

  javadoc: "1.6"

  jaxb: "2.3.0"

  jdk-tool: "1.0"

  jenkins-design-language: "1.25.1"

  jjwt-api: "0.11.2-9.c8b45b8bb173"

  job-dsl: "1.77"

  jobConfigHistory: "2.28.1"

  jquery3-api: "3.6.0-2"

  jsch: "0.1.55.2"

  junit: "1.53"

  lockable-resources: "2.12"

  mailer: "1.34"

  matrix-auth: "2.6.8"

  matrix-project: "1.19"

  maven-plugin: "3.15"

  metrics: "4.0.2.8"

  momentjs: "1.1.1"

  okhttp-api: "3.14.9"

  parameterized-trigger: "2.41"

  pipeline-build-step: "2.15"

  pipeline-graph-analysis: "1.11"

  pipeline-input-step: "2.12"

  pipeline-milestone-step: "1.3.2"

  pipeline-model-api: "1.9.2"

  pipeline-model-definition: "1.9.2"

  pipeline-model-extensions: "1.9.2"

  pipeline-rest-api: "2.19"

  pipeline-stage-step: "2.5"

  pipeline-stage-tags-metadata: "1.9.2"

  pipeline-stage-view: "2.19"

  pipeline-utility-steps: "2.10.0"

  plain-credentials: "1.7"

  plugin-util-api: "2.5.0"

  popper-api: "1.16.1-2"

  popper2-api: "2.10.2-1"

  pubsub-light: "1.16"

  resource-disposer: "0.16"

  run-condition: "1.5"

  scm-api: "2.6.5"

  script-security: "1.78"

  snakeyaml-api: "1.29.1"

  sse-gateway: "1.24"

  ssh-credentials: "1.19"

  ssh-steps: "2.0.0"

  sshd: "3.1.0"

  structs: "1.23"

  swarm: "3.28"

  thinBackup: "1.10"

  timestamper: "1.13"

  token-macro: "266.v44a80cf277fd"

  trilead-api: "1.0.13"

  variant: "1.4"

  webhook-step: "1.4"

  workflow-aggregator: "2.6"

  workflow-api: "2.47"

  workflow-basic-steps: "2.24"

  workflow-cps: "2.94"

  workflow-cps-global-lib: "2.21"

  workflow-durable-task-step: "2.40"

  workflow-job: "2.42"

  workflow-multibranch: "2.26"

  workflow-scm-step: "2.13"

  workflow-step-api: "2.24"

  workflow-support: "3.8"

  ws-cleanup: "0.39"
```

Start in CpsFlowExecution.cleanUpObjectStreamClassCaches, following its callers cleanUpLoader and cleanUpHeap, then compare the reported ClassCastException with the restart path through CpsThreadGroup. Reproduce the failure around a restarted running pipeline and verify that affected pipelines resume without this exception or cleanup warning.

Written by the indexing model from the issue text.