Need an alternate way in creation of multiple nodes in jenkins - jenkins

I have 15 hosts and 20 users. Need to create a node with the combination of each host with 20 users. So EOD I should create 15(hosts)*20(Users)=300(Nodes).
For me creating these many nodes and managing them is a very hectic job. Do we have any alternate way to run the jobs with the above combinations.
Please guide me on this.

You can write down some code to manage the Node and increase or decrease with the code as per need.
For example here is Ansible role : https://github.com/lean-delivery/ansible-role-jenkins-slave
You can use this to add a node and it will join to the master of Jenkin.

Related

How to run a Jenkins job in an available agent

I have a Jenkins master and two agents. However the connectivity to one agent(agentA) is bit shaky and I want to use the other agent(agentB) when the connectivity to the first one is not available.
I am only using the Jenkins web interface and have not used scripts. I am trying to figure out how it can be done using the "Restrict where this project can be run" option in job's configuration. I tried using agentA|| agentB but when agentA is not available it hangs saying "pending - agentA is offline"
Is it possible to have a configuration to achieve what I need?
I can;t leave it blank because I have other agent (agentC, agentD) which do not want this job to run in.
I am not an admin of the Jenkins server, hence adding new plugins is not my preferred option but it can be done.
As noted in Least Load plugin,
By default Jenkins tries to allocate a jobs to the last node is was executed on. This can result in nodes being left idle while other nodes are overloaded.
As you generalized the example, I'm not 100% sure if your situation can be solved by simply better labelling of your nodes or you want to look at least load plugin (it is designed for balancing the load across nodes). Your example appears to show Node names (ie; agentA/agentB). The Queue allocation logic may be "Only A or Only B", then Jenkins sticks to it. Load balancing may not address that as while a Node (a Computer) name is also a label, it may have additional logic tied to it.
If you label the pair of nodes in a pool with a common label, say "CapabilityA", and constrain your jobs to run where "CapabilityA" rather than the node names, you may find jobs float across the pool (to B if A is not available. That's how we have our nodes labelled - by Capability, and we see jobs floating across nodes, but only once the first node is full (4 executors each), so not balanced.
Nodes can have many labels and you can use label conditions to have complex constraints.

Jenkins grouping of nodes via label on demand

I have a scenario where I have N numbers of nodes and N number of tests, and these tests will be distributed to the nodes. My nodes have a label Windows.
Here's an example:
I have a pipeline job that will manage the distribution of the tests to the nodes. I set my pipeline job to run 10 tests on 10 VMs having the label Windows and it will run smoothly. However, one of my requirements is to concurrently run that pipeline job. The problem I might encounter If I have 10 tests on VMs 1-10 in the first run of the job, and run another job for 5 tests for VMs 11-15, given that I am using the Windows label, there might be a possibility that Jenkins will assign the test to VMs 1-10 but should run on VMs 11-15 or vice versa.
The solution I came up with is to dynamically change the label of the VMs from one of the jobs to a unique label that will only be used for that Job. Unfortunately, I still don't know how to do that.
Basically, I just want to logically group my nodes via label on demand in my pipeline script.
I searched all throughout the internet and yet I still wasn't able to find a solution that fits my needs.
Kindly help me with this. Also, I am open to using a different approach.

How to batch schedule dask_jobqueue jobs in DASK instead of concurrent?

By my reading of Dask-Jobqueue (https://jobqueue.dask.org/en/latest/), and by testing on our SLURM cluster, it seems when you set cluster.scale(n), and create client = Client(cluster), none of your jobs are able to start until all n of your jobs are able to start.
Suppose you have 999 jobs to run, and a cluster with 100 nodes or slots; worse yet, suppose other people share the cluster, and maybe some of them have long-running jobs. Admins sometimes need to do maintenance on some of the nodes, so they add and remove nodes. You never know how much parallelism you'll be able to get. You want the cluster scheduler to simply take 999 jobs (in slurm, these would be submitted via sbatch), run them in any order on any available nodes, store results in a shared directory, and have a dependent job (in slurm, that would be sbatch --dependency=) process the shared directory after all 999 jobs completed. Is this possible with DASK somehow?
It seems a fundamental limitation of the architecture, that all the jobs are expected to run in parallel, and the user must specify the degree of parallelism.
Your understanding is not correct. Dask can run with fewer than the specified number of jobs, just as you've asked for. It will use whatever resources arrive.

Run one or many concurrent jobs in Jenkins with different parameters

I am trying to create a jenkins job that will run some code on various servers to validate them.
I would like to be able to specify either an individual server or give a directive such as "evens" for servers 02, 04, 06... or "odds" for servers 01, 03, 05... and have the job run for either a single or many servers.
I'm searching for the cleanest way to do this, I've tried using a scheduler job that would handle the odds and evens cases but would prefer, if possible, not to have to split the single and many server cases into different jobs. I've also looked into using a matrix job that could be configured to run under different parameter set but haven't found any documentation to fully solve my problem.
Can anyone point me in the right direction?
I am not sure I fully understood you but I will try:
I understood that you want to activate the same job many times with different parameters.
your options are :
1. using master job that will activate all other jobs with different parameters ( like you said with matrix or even simpler )
2. you can do it in pipeline rather easily with node scopes and loops for using different parameters
3. you can use jenkins-cli and activate the same job with different parameters every activation.
I hope it helped you

jenkins change label as requested

We use jenkins for automation for our test infrastructure. The requirement is to give users the ability to use a jenkins node for their private test or debug using private jenkins jobs and then put back in the pool of nodes marked with labels; so that other jobs that were marked to run on particular labels can be run without interference.
We can achieve this by letting users alter label, but that didnt workout as users (nearly 50) are making their own label names and it takes time for admin to reassign the nodes (even with process) and precious test time is getting affected.
we are looking for some solution such as ability to provide buttons like take this node offline (cant use this option since jenkins cannot see the node anymore and so users cannot run jenkins job on the node) but may be with the ability to run scripts.
I have done some research on this but have to compromise on some requirements, so i decided to seek help from the community... SUGGESTIONS?
Did you have a look to this question:
How to take Jenkins master node offline using CLI?
In the 1st question, there are some CLI to make a node offline.
Maybe you can create a dedicated job on the master with one parameter (the node name). This job will call the Jenkins CLI to stop your node.

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