[JENKINS-70446] Amazon EC2 nodes created and connected but the job is ran on the master.

Currently, We have one amazon account linked with the plugin with multiple AMI's for windows and Linux. We don't see any issue with Windows but for the Linux agent we are occasionally seeing the below problem. Our nodes are set to limit of 5 Uses.

Problem:

• Nodes are created as per when the resource is per the resource requirement.


• On a rare occasion, the Jenkins Coordinator creates a new Jenkins EC2 Agent, however the IP address assigned to the “Jenkins Worker Node” is the same as the Jenkins Coordinator IP address

Debugging:

• Looked at the AMI to verify all the versions are right and installed correctly. Looks good.


• Added more print statements to debug more like printing hostname and IP address.

 

Jenkins Master --> m4.4xlarge 

Linux Agent --> C5Large

Note: This happens occasionally sometimes 3 to 4 times a week. We even checked the load of the Jenkins Master to see if there is any pattern but found none.

Please let me know if you need anymore information from me.

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Originally reported by vjannapureddy, imported from: Amazon EC2 nodes created and connected but the job is ran on the master.

• assignee: thoulen
  
• status: Open
  
• priority: Major
  
• component(s): ec2-plugin
  
• resolution: Unresolved
  
• votes: 1
  
• watchers: 3
  
• imported: 2025-12-06
  

Raw content of original issue

Currently, We have one amazon account linked with the plugin with multiple AMI's for windows and Linux. We don't see any issue with Windows but for the Linux agent we are occasionally seeing the below problem. Our nodes are set to limit of 5 Uses.


Problem:



	
Nodes are created as per when the resource is per the resource requirement.

	
On a rare occasion, the Jenkins Coordinator creates a new Jenkins EC2 Agent, however the IP address assigned to the “Jenkins Worker Node” is the same as the Jenkins Coordinator IP address



Debugging:



	
Looked at the AMI to verify all the versions are right and installed correctly. Looks good.

	
Added more print statements to debug more like printing hostname and IP address.



 


Jenkins Master --> m4.4xlarge 


Linux Agent --> C5Large


Note: This happens occasionally sometimes 3 to 4 times a week. We even checked the load of the Jenkins Master to see if there is any pattern but found none.


Please let me know if you need anymore information from me.

• environment: Jenkins 2.346.2(m4.4xlarge), Amazon EC2 Version2.0.4, openjdk 11.0.16 2022-07-19 LTS, Agent (C5Large)

No source file or test is named. Start by reproducing the intermittent Linux-agent case in the ec2-plugin and compare the coordinator and worker IPs, node assignment, and job execution behavior with Windows agents. Done means identifying why a job runs on the master and preventing that incorrect assignment, with a regression test or reproduction details.

Written by the indexing model from the issue text.