[JENKINS-55492] Plugin is not reusing stopped AWS EC2 instances

Using 1.39 of the plugin, the behaviour I observed was that when the instance cap was set to 2 and 2 slaves were already provisioned (e.g. in the stopped EC2 state rather than  terminated), when a slave is required for a pending queued build, the plugin used to simply start one of the 2 stopped instances as required.

 

Now, on 1.42, the plugin appears to leave the previous 2 EC2 instances in the stopped state on AWS and provision a brand new slave, leading to it exceeding the instance cap of 2 and there now being 3 EC2 instances (albeit 2 stopped and only 1 running).

For now, my workaround was to go back to 1.39.

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Originally reported by davidgoate, imported from: Plugin is not reusing stopped AWS EC2 instances

• assignee: thoulen
  
• status: Open
  
• priority: Major
  
• component(s): ec2-plugin
  
• resolution: Unresolved
  
• votes: 3
  
• watchers: 10
  
• imported: 2025-12-06
  

Raw content of original issue

Using 1.39 of the plugin, the behaviour I observed was that when the instance cap was set to 2 and 2 slaves were already provisioned (e.g. in the stopped EC2 state rather than  terminated), when a slave is required for a pending queued build, the plugin used to simply start one of the 2 stopped instances as required.


 


Now, on 1.42, the plugin appears to leave the previous 2 EC2 instances in the stopped state on AWS and provision a brand new slave, leading to it exceeding the instance cap of 2 and there now being 3 EC2 instances (albeit 2 stopped and only 1 running).


For now, my workaround was to go back to 1.39.

• environment: Plugin version 1.42

Start by tracing the EC2 plugin's instance provisioning and reuse behavior for stopped AWS instances, comparing the reported 1.39 and 1.42 behavior. Reproduce the case with a cap of 2 and two stopped instances; it is done when a queued build reuses a stopped instance and the cap is not exceeded.

Written by the indexing model from the issue text.