Bug 1814547 - [Descheduler] Duplicate strategy is evicting the deploy pod in the RC which is preventing new pods from being created
Summary: [Descheduler] Duplicate strategy is evicting the deploy pod in the RC which ...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: OpenShift Container Platform
Classification: Red Hat
Component: kube-scheduler
Version: 4.5
Hardware: Unspecified
OS: Unspecified
unspecified
medium
Target Milestone: ---
: 4.5.0
Assignee: Mike Dame
QA Contact: RamaKasturi
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2020-03-18 07:56 UTC by RamaKasturi
Modified: 2020-07-13 17:22 UTC (History)
2 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Cause: Descheduler RemoveDuplicates strategy considered any pods with the same ownerref to be duplicates and would indiscriminately evict some of them at random Consequence: DeploymentConfigs create a separate "deploy" pod, which is not one of the replicas but does have the same ownerref as a replica. When the descheduler evicted this pod, it did not get recreated and this broke the DC. Fix: Add stricter requirements for what is considered a duplicate pod (including verifying the same images used) and add an optional field to exclude certain kinds of ownerrefs , such as DeploymentConfigs. Result: This issue is no longer present with DCs
Clone Of:
Environment:
Last Closed: 2020-07-13 17:22:24 UTC
Target Upstream Version:
Embargoed:


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Links
System ID Private Priority Status Summary Last Updated
Github openshift descheduler pull 30 0 None closed bug 1814547: Rebase upstream 1.18 2020-06-19 15:08:04 UTC
Red Hat Product Errata RHBA-2020:2409 0 None None None 2020-07-13 17:22:45 UTC

Description RamaKasturi 2020-03-18 07:56:28 UTC
Description of problem:
Duplicate strategy is evicting the deploy pod in the RC which is preventing new pods from being created.

Version-Release number of selected component (if applicable):
4.4.0-rc.1

How reproducible:
Always

Steps to Reproduce:
1. Install descheduler operator via OLM
2. Add the duplicate strategy.
3. Now create pods by running the command below "oc run hello --image=openshift/hello-openshift:latest --replicas=12"
4. While the pods are in ContainerCreating state edit the kubedescheduler object to change the interval seconds to some value.

Actual results:
Now user can see that all pods goes into terminating state including the deployer pod and the descheduler evicts the deployer pod due to which the pods never come up.

Expected results:
deployer pod should not be evicted as this would prevent more pods from creation.

Additional info:
This is a symptom of https://github.com/kubernetes-sigs/descheduler/issues/230

Comment 1 Maciej Szulik 2020-03-18 16:49:20 UTC
We spoke about it with Mike and I doubt we'll fix it for 4.4, moving to 4.5

Comment 2 Mike Dame 2020-05-01 18:33:37 UTC
Pr upstream to address this in a quick way: https://github.com/kubernetes-sigs/descheduler/pull/275

Comment 5 RamaKasturi 2020-05-21 14:41:48 UTC
Verified with the payload below and do not see the issue happening, moving the bug to verified state.

[ramakasturinarra@dhcp35-60 Downloads]$ oc get clusterversion
NAME      VERSION                             AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.5.0-0.nightly-2020-05-21-072118   True        False         3h9m    Cluster version is 4.5.0-0.nightly-2020-05-21-072118

Comment 7 errata-xmlrpc 2020-07-13 17:22:24 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:2409


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