20 Parallel Branches Starved Jenkins of Every Executor — Jenkins Pipeline Stages & Parallel
A pipeline with 20 parallel branches, each spawning its own node block, consumed all controller executors and blocked the main thread — 0 available executors. This is stages and parallelism done right: sequential vs parallel stages, executor/node allocation, the failFast option, and keeping parallel fan-out from deadlocking your controller.
⏳ Timestamps:
0:00 - Cold open: 0 available executors
0:22 - Intro
0:30 - What Is It?
0:44 - Why Stages Exist
1:11 - Parallel Execution
1:39 - Fail Fast
2:05 - Locking Resources
2:34 - Matrix Parallelism
3:06 - When NOT to Parallelize
3:21 - 0 available executors
3:40 - Incident Deep-Dive: Fix
3:57 - ⚠ Gotcha: Running parallel node blocks on controller
4:10 - ⚠ Gotcha: Omitting agent none at pipeline level
4:25 - ⚠ Gotcha: failFast kills branches before cleanup
4:40 - ⚠ Gotcha: Matrix with too many combinations
4:52 - Dynamic Parallel Branches with Scripted Pipeline
5:11 - Parallelism with Shared Workspace Pitfall
5:49 - Debugging Guide
6:03 - Interview Questions
6:28 - FAQ
6:53 - Key Takeaways
7:08 - Next up
7:20 - Wrap-up
👉 Full article + code: https://thecodeforge.io/devops/jenkin...
⏭ Next up: Jenkins Shared Libraries
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