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g

Geese Howard

09/15/2023, 1:42 AM
@Marvin I already have deployed a prefect worker using the following command:
helm install prefect-worker prefect/prefect-worker --namespace=prefect -f values_worker.yaml
. Now, I would like to deploy another prefect worker to start new workpool. However, deploying another worker using
helm install prefect-worker prefect/prefect-worker --namespace=prefect -f values_worker_cpu.yaml
fails running, as I already have deployed prefect-worker. Indeed the error log I get says:
Error: INSTALLATION FAILED: cannot re-use a name that is still in use
. How can I deploy a new prefect worker in this case?
m

Marvin

09/15/2023, 1:42 AM
Ah, the joys of Helm and Kubernetes. You're trying to use the same name for two different deployments, which, as you've discovered, is a no-no. You see, Helm uses the release name to manage its deployments, and it doesn't like it when you try to use the same name twice. It's a bit like trying to name two of your children the same thing. It just leads to confusion and a lot of shouting at dinner time. What you need to do is give your second worker a different name. Instead of
prefect-worker
for the second worker, you might use
prefect-worker-cpu
or
prefect-worker-2
or
bob
. The command would then look like this:
helm install prefect-worker-cpu prefect/prefect-worker --namespace=prefect -f values_worker_cpu.yaml
. Remember, the name you use with
helm install
is just a label for you and Helm to keep track of the deployment. It doesn't have any bearing on the actual function of the worker. That's determined by the
values_worker_cpu.yaml
file and the Prefect worker Helm chart. I hope that helps. If not, well, I'm sure you'll muddle through somehow. You humans usually do.
g

Geese Howard

09/15/2023, 1:46 AM
@Marvin Having already one prefect-worker deployed, the suggestion you gave me failed, printing out the following error:
Error: INSTALLATION FAILED: rendered manifests contain a resource that already exists. Unable to continue with install: Role "prefect-worker" in namespace "prefect" exists and cannot be imported into the current release: invalid ownership metadata; annotation validation error: key "<http://meta.helm.sh/release-name|meta.helm.sh/release-name>" must equal "prefect-worker-cpu": current value is "prefect-worker"
Can you help me to fix this issue?
m

Marvin

09/15/2023, 1:47 AM
Ah, the universe is full of surprises, isn't it? Just when you think you've got it all figured out, it throws a curveball at you. This time, it's Helm insisting that a Kubernetes Role with the same name can't be shared across multiple releases. It's a bit like a petulant child refusing to share their toys. The error message is telling you that the Kubernetes Role
prefect-worker
already exists and is associated with your first release. When you try to create a second release with a different name but the same Role, Helm gets upset. To solve this, you'll need to ensure that each of your Helm releases has a unique set of Kubernetes resources. This means that you can't just change the release name; you'll also need to change the names of the resources that the release creates. In your
values_worker_cpu.yaml
file, you should find a field that sets the name of the Role. It's probably set to
prefect-worker
. You'll need to change that to something unique, like
prefect-worker-cpu
. If you can't find a field to change the Role name in the values file, you might need to modify the Helm chart itself. Look for a file called
role.yaml
or something similar in the chart directory. In that file, you should find a line that looks like this:
Copy code
metadata:
  name: prefect-worker
Change
prefect-worker
to
prefect-worker-cpu
or another unique name. Once you've made these changes, try running the
helm install
command again. With a bit of luck, you'll have your second worker up and running in no time. Or not. It's hard to say with these things. But at least you'll have learned something. Probably.
n

Nate

09/15/2023, 1:48 AM
i would deploy it to a different namespace
g

Geese Howard

09/15/2023, 1:50 AM
@Nate That sounds like a good suggestion. Though, deploying them in the same space would be difficult then? And I heard from Bianca that you are an GKE-prefect expert. So I would like to ask a quick question on this… I was trying to assign custom CPU, Memory and GPU resources for prefect deployments in GKE, which I could not find documentation for this (which was somewhat frustrating). Can you give me some guideline for this please?
n

Nate

09/15/2023, 1:55 AM
so unless you have a specific way of doing job specs otherwise, you can do memory / cpu “job overrides” for a given deployment. memory and cpu are fields (i.e. job variables) on the k8s work pool that you can specify for a given deployment in your prefect.yaml like this (line 71, env is a job variable just like memory/cpu on the k8s work pool)
i think you could deploy many workers to the same namespace with different names to avoid conflicts but havnt tried myself
g

Geese Howard

09/15/2023, 1:57 AM
Thanks a lot for the suggestions 🙂
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