I have master jenkins and slave jenkins. I hav kept slave jenkins no of build executors as 1. Slave Jenkins also has 1 pipeline (Lets say pipeline A).
lets suppose a job from slave jenkins' own pipeline is running right now (Job A). I schedule a job from the master jenkins for slave jenkins (Job B).
I dont want Job B to run while job A is running as both jobs use shared resources.
Right now, Job B runs in parallel with Job A, which is causing Job A to fail.
How to do that?
Thanks!
Your implementation is a bit tricky since you are talking about 2 separate machines with 2 separate Jenkins instances. One option is to get rid of the Jenkins instance in the slave machine and move the Jenkins job that runs on it to the master machine. Then, you can schedule the job to use the resources of the slave machine while being managed by the master machine. If you do that, no further configuration will be needed since you have set the number of executors to 1.
If that is not possible, the other option is to find a way for them to communicate with each other that a build is running. Consider the third point of this answer. You can have a variable in a database somewhere and when one job starts, it updates the variable. Before the second job starts, it has to poll the variable to see if there is a job already running. If yes, the build doesn't start, if no, build starts and updates the variable.
Another less elegant solution is to simply have a text file in a location accessible to both machines and write the variable data into that instead of a database.
One way to do this is by using the Lockable Resources Plugin.
Related
Currently, we have two machines. One has Jenkins installed and is hosted as master in Jenkins and another one is Slave. Number of executors for both Nodes are set to 1.
I am not exactly sure how Jenkins work behind the scenes but currently when I triggered 2 build jobs simultaneously, it somehow runs only on slave node (and put another build job in queue), if I disconnect the slave and leave only master, then it would run on master(and put another build job in queue).
How to configure Jenkins so that it leverage all my available nodes (master and slave). In other words, I would like to have all available nodes consumes the queue and not just for one of the Nodes.
As I understand, you need to enable Execute concurrent builds if necessary option in your job configuration and then you will be able to run your job simultaneously on all available nodes.
In addition to the above answer. We can also restrict the job to a particular node on which it should run.
For eg
A setup of 3 servers(2 Linux and one windows )
1 Linux server acts as master
1 Linux server acts as node
1 window server as as node
If we have a job that needs to be run on the windows node you can go to the job configuration and restrict the job to run on that node using the node name or label.
Additionally, the no. of executes define the instances of the slave or master node that can be executed parallelly across different jobs.
For running same job you need to check the enable concurrent build option and assign a label having more than 1 nodes in it
Cheers,
Yash
My job failed due to some reason. I want to go to the machine who actually run the job.
How do I know if a job is configured to use slaves?
How do I know which slave was used in that job?
By default all jobs are able to use all nodes, including the master as an executor. If you want to lock a job down to a particular slave, you can do so by selecting it in Job > Configuration > General > Restrict where this job can run.
To see which host a job ran on, click on the build number and in the top right it will say 'Started ~duration~ on ~host~', where ~host~ is your slave (or master).
I am curios if it's possible to have one computer/node that would be shared between two jenkins instances?
I know that one can make two same copies of node configurations on Jenkins instances and change workspace, but I am aiming for this scenario.
Jenkins A with Node A
Jenkins B with Node A
Jenkins A starts job on Node A
Jenkins B puts Node A offline
Jenkins B starts job on Node A
Jenkins A puts Node A offline
Node A can only be used once at a time, and there should not be parallel jobs running no matter of different workspaces.
I know that it can be achieved when you have one jenkins instance, but how to do it if you have to use two of them at least?
NOTE: both Jenkins instances are located on different machines.
I believe jenkins mesos plugin is what you needed.
Use following steps to install & configure:
step1
step2
step3
step4
Of course, you had to install a mesos cluster for yourself before do above, see mesos official site. This may cost some time if you are not familar with mesos.
And in step4, you'd better set slave cpus equal with the number of your real slave node.
The principle is:
Mesos first sends resource offer to Jenkins Master A, then jenkins master A will launch tasks on the slave node A, as the resource was used by jenkins master A now. Resource offer will not be sent to Jenkins Master B again, so Jenkins Master B is waiting.
After Jenkins Master A finish task, mesos resource offer for slave node A will be sent to Jenkins Master B, then Jenkins Master B can start task.
The slave can be used by Jenkins Mesos A & Jenkins Mesos B, but never at the same time.
Hope it help you.
I have configured a multibranch-pipeline project in Jenkins. This project run integration test on all my feature branches (git). For each job in the pipeline project it creates an instance of my webapp (start tomcat and other dependencies). Because of port binding issues this result in many broken jobs.
Can I throttle the builds in the multibranch-pipeline project, so that the jobs for each feature branch run sequentially instead of parallel?
Or if there any more elegant solution?
Edit:
Situation and problem:
I want to have a multibranch pipeline project in Jenkins (because I have many feature branches in git)
The jobs which are created from the multibranch pipeline (for each feature branch in git), run in parallel
Polling scm is at midnight (commits on x branches are new, so the related jobs started at midnight)
every job started one instance of my webapp (and other dependencies) which bind to some ports
The problem is, that there can start many of these jobs at midnight. Every job will try to start an instance of my webapp. The first job can start the webapp without any problem. The second job cannot start the webapp because the ports are already taken from the first instance.
I don't want to configure a new port binding for each feature branch in my git repository. I need a solution to throttle the builds in the multibranch pipeline, so that only on "feature" can run concurrently.
From what I've read in other answers the disableConcurrentBuilds command only prevents multiple builds on the same branch.
If you want only one build running at a time, period, go to your Nodes/Build Executor configuration for the specific VM that your app is running on, drop the number of executors to 1 and configure the node labels so that only jobs from your multibranch pipeline can run on that VM.
My project has strict memory, licensing and storage constraints, so with this setup, all the jobs on the master and feature branches start, but only one can run at a time until the executor becomes available.
The most elegant solution would be to make your Integration Tests to be able to run concurrently.
One solution would be to use an embedded tomcat with a dynamic port. In that way each job instance would run in tomcat with different ports.
This is also a better solution than relying on an external server.
If this is too much work, you can always use the following code in your "jenkinsfile" pipeline:
node {
// This limits build concurrency to 1 per branch
properties([disableConcurrentBuilds()])
// continue your pipeline ...
}
The solution comes from this SO answer.
I have several integration tests within my Jenkins jobs. They run on several application servers, and I want to make sure that only one integration test job is run at the same time on one application server.
I would need something like a tag or variable within my jobs which create a group of jobs and then configure the logic that within that group, only one job may run at the same time.
Could I use the Exclusion plugin for that? Does anyone have experience with it?
Use the Throttle Concurrent Builds Plugin. It replaces the Locks and Latches plugin, and provides the capability to restrict the number of jobs running for specific labels.
For example: you create a project category 'Integration Test Server A' and tie jobs to it with a maximum concurrent count of 1, and a second 'Integration Test Server B' label and tie other jobs to it, both categories will only run a single concurrent build (assuming you've set a max job count of 1), and the other jobs in that category will queue until the 'lock' has cleared.
Using this method, you don't have to restrict the number of executors available on any specific Jenkins instance, and can easily add further slaves in the future without having to reconfigure all your jobs.
If I understand you right, you have a pool of application servers and it doesn't matter on what server your tests run. They only need to be the only test on that server.
I haven't seen a plugin that can do that. However, you can get easily around it. You need to configure a slave for each application server. (1 slave = 1 app server) You need to assign the same label to all slaves and every slave can only have one executor. Then you assign the jobs that run the integration tests, to run on that label. Jenkins will assign the jobs then to the next available slave (or node) that has that label.
Bare in mind that you can have more than one slave running on the same piece of hardware and even a master and a slave can coexist on the same server.
Did you check below parameter in the Jenkins -> Manage Jenkins -> Configure system
# of executors
The above parameter helps you restrict the number of jobs to be executed at a time.
A Jenkins executor is one of the basic building blocks which allow a build to run on a node/agent (e.g. build server). Think of an executor as a single “process ID”, or as the basic unit of resource that Jenkins executes on your machine to run a build. Please see Jenkins Terminology for more details regarding executors, nodes/agents, as well as other foundational pieces of Jenkins.
You can find information on how to set the number of Jenkins executors for a given agent on the Remoting Best Practices page, section Number of executors.
Source - https://support.cloudbees.com/hc/en-us/articles/216456477-What-is-a-Jenkins-Executor-and-how-can-I-best-utilize-my-executors