This issue would appear to be related:

https://issues.jenkins-ci.org/browse/JENKINS-12240

...but suggests a desire for the opposite behaviour: as many configurations of a particular job as possible should run on a node.

However, I'm sure there are just as many people who want the behaviour I'm describing, here's an example:

https://issues.jenkins-ci.org/browse/JENKINS-13619

I've just verified that this is a regression in 1.7.2.

1.7.1 behaves as expected, so I'll downgrade to that as a workaround...

https://issues.jenkins-ci.org/browse/JENKINS-16552 is a duplicate of this issue.

I tried 1.7.1 but had the same unwanted behaviour as 1.7.2!

I'm also now seeing this on 1.7.1 with 1.480.3 :-/

Same here. Version 1.72 and 1.513 of Jenkins. Is this, https://issues.jenkins-ci.org/browse/JENKINS-12240, supposed to fix it? It is included in version 1.72 according to commits.

Update: Cloned tag 1.7.1 and installed and it seems to work using Category.
Created a "Matrix-job" category using "Maximum Total Concurrent Build = 4" and "Maximum Concurrent Builds Per Node = 4". The job itself is configured with "Maximum Concurrent Builds Per Node = 1" and "Maximum Total Concurrent Build = 4". I am not using any slaves though.

Yeah, I thought it was working, and then found overlapping matrix child jobs on some slave nodes.
So, have to default to one executor per slave, which means those slaves can't be used for any other jobs (that don't use the throttled resources), which is a waste

Hi Andrew(Abayer),
Can you please fix this and release 1.7.3 fast.
or if any one has already done fix..please do the pull request to get it merged.

Reassigned the issue

Hi,
is this behaviour somehow related to issue we've see lately with matrix jobs and throttle-plugin: throttle plugin do not recognize slave nodes that has been added after the matrix jobs has been gone to queue. Resulting those jobs going to slave nodes that has been there before job launch and new nodes doing nothing.

No, that sounds entirely unrelated. Please file a separate issue for that.

I'd say that the issue completely duplicates JENKINS-13619.

BTW, I've started working on the configurable behavior for Matrix projects. It should resolve both issues.

Hi,
we have another issue with matrix and throttle-concurrents, I cannot say if it is related to this.

We have 4 executors on a node and 2 matrix projects using them. Each matrix project spawns 4 jobs. Jobs from the same matrix project can run in parallel on the same node but they conflict with jobs from other projects. So we configured the two jobs with the same category and specified to run 1 job per node. Unfortunately jobs from different projects in the same category are spawned to the same node.
We would expect to have 4 jobs from the same project... or at least 1 job from a single project and 3 free executors, not mixed project jobs.

We did the following:

Global configuration:
Category Name: mock

• Maximum Total Concurrent Builds: 0
• Maximum Concurrent Builds Per Node: 1

Job configurations:
Throttle Concurrent Builds => checked
Throttle this project as part of one or more categories => selected

• Maximum Total Concurrent Builds: 0
• Maximum Concurrent Builds Per Node: 1
• Multi-Project Throttle Category: mock

We also tried to specify the per-node global conf without any help. We also tried to set the limit for the master node (which is used as the main executor for the matrix jobs). No luck.

Note the same configuration with other non-matrix projects works fine.

Jenkins version: 1.559
Throttle Concurrent Builds Plug-in version: 1.8.2

Should I open another issue for this problem?

@Andrea
This is a similar issue.
I'll provide a Dev Build of the plugin in JENKINS-13619

Marking as duplicate.
Let's track the further activity in JENKINS-13619