How to Deal With: “Jenkins detected that you appear to be running more than one instance of Jenkins” on MacOS

MacOS: Catalina. Here’s my specs.

I am running two instances of Jenkins and I don’t know why or how this happened. Nonetheless, I will heed the warning.

I check the activity monitor but this seems to be of no use

as a search for Jenkins reveals nothing,

Using top is not that useful either,

No Jenkins here… I do see a random Java process, which could be related, but I can’t be sure yet,

Changing the search in the Activity Monitor to “Java” gives me what I want

On the right side you can see my two Java processes, on the left side you can see that their PIDs match exactly the ones mentioned in the error message shown in the browser. Nice.

I click the ignore button to go to Jenkins in the browser.

I start using Jenkins so I can see which instance actually gets used. It’s CPU usage should go up in the Activity Monitor

Cool. So I’m gonna keep the top one and trash the bottom one not being used.

Problem solved. As far as figuring out how both of them got spun up, that’s another issue. It’s probably related to how you installed and configured it, if you installed it twice, etc.

XR Developer at HookBang