percona / percona/percona-server-mongodb-operator

Reconciliation calls kube-apiserver 1000/sec with high concurrency and many databases

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#2,136 2 comments 0 reactions 0 assignees View on GitHub

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1.24.0 bug
Dominant language
Go
Stars
456
Forks
198
Avg merge
5d 19h
Merged PRs (30d)
10

Description

Report

We have 100 PSMDB defined. The operator is calling kube-apiserver over 1000x/sec with a MAX_CONCURRENT_RECONCILES of 60. Reducing to 2 lowers it to merely dozens of calls per second.

More about the problem

We have EKS audit logging enabled and the increased concurrency is causing a noticeable increase to our cloudwatch bill.

Steps to reproduce
  1. Be on operator 1.21.1
  2. Turn up MAX_CONCURRENT_RECONCILES
  3. Define many clusters
Versions
  1. Kubernetes v1.32
  2. Operator v1.21.1
  3. Database 6-8 (various versions)
Anything else?

I reported it as a bug because I'm not sure this level of activity is intended. But maybe this is actually a feature request for a parameter to slow down the reconciliation loop.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the operator's MAX_CONCURRENT_RECONCILES setting and reproduce the reconciliation traffic using many PSMDB clusters on operator 1.21.1. Determine whether the observed kube-apiserver call rate is expected, then establish whether the fix should reduce unnecessary calls or expose a way to limit reconciliation; done means the behavior is verified and the expected call rate or control is covered.

Written by the indexing model from the issue text.

Assessment

Tech stack
go, kubernetes, mongodb
Domain
databases, devops, infrastructure
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

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