Bug #56415: cephadm uses static placement when creating daemons causing a hotspot on the 'root' node - Orchestrator - Ceph

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Bug #56415

closed

cephadm uses static placement when creating daemons causing a hotspot on the 'root' node

Added by Redouane Kachach Elhichou almost 2 years ago. Updated almost 2 years ago.

Status:

Resolved

Priority:

High

Assignee:

Redouane Kachach Elhichou

Category:

cephadm

Target version:

% Done:

Source:

Tags:

Backport:

quincy,pacific

Regression:

Severity:

3 - minor

Reviewed:

Affected Versions:

ceph-qa-suite:

Pull request ID:

46892

Crash signature (v1):

Crash signature (v2):

Description

cephadm uses static placement when creating daemons. As consequence, most of the deamons end up in the first node (the one used to bootstrap the cluster) creating a hotspot on this node. In a cluster of 4 nodes and after creating several daemons right now the result is an unbalanced cluster:

   [ceph: root@ceph-node-0 /]# for i in `seq 0 3`; do echo ceph-node-$i; ceph orch ps | grep ceph-node-$i | wc -l; done
   ceph-node-0
   15
   ceph-node-1
   14
   ceph-node-2
   4
   ceph-node-3
   4

cephadm used to distribute the load randomly across the cluster but this was broken by the change: https://github.com/ceph/ceph/commit/adceaa9b28278601c56a7db1c3f42eaa592ec4d1 (introduced as part of the PR https://github.com/ceph/ceph/pull/41007). So all versions containing this change suffer from this issue.

Related issues 4 (1 open — 3 closed)