From 161404813c8970f89cbdb4c5e8709ddf89a69ea8 Mon Sep 17 00:00:00 2001 From: Aliaksandr Valialkin Date: Wed, 17 Apr 2024 11:56:11 +0200 Subject: [PATCH] docs/Cluster-VictoriaMetrics.md: clarify per-node workload increase when one of vmstorage node is unavailable in the cluster The docs update is based on https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6099#issuecomment-2060856417 --- docs/Cluster-VictoriaMetrics.md | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/docs/Cluster-VictoriaMetrics.md b/docs/Cluster-VictoriaMetrics.md index da1eb5d19..8fbadfcc7 100644 --- a/docs/Cluster-VictoriaMetrics.md +++ b/docs/Cluster-VictoriaMetrics.md @@ -466,8 +466,9 @@ General recommendations for cluster scalability: since every `vmstorage` node contains lower number of time series when the number of `vmstorage` nodes increases. The cluster stability is also improved with the number of `vmstorage` nodes, since active `vmstorage` nodes need to handle lower additional workload - when some of `vmstorage` nodes become unavailable. For example, if one node out of 5 is unavailable, 20% of the load is re-distributed across 4 remaining nodes. - If one node out of 10 nodes is unavailable, 10% of the load is re-distributed across 9 remaining node. + when some of `vmstorage` nodes become unavailable. For example, if one node out of 3 nodes is unavailable, then `1/3=33%` of the load is re-distributed across 2 remaining nodes, + so per-node workload increase is `(1/3/2)/(1/3) = 1/2 = 50%`. + If one node out of 10 nodes is unavailable, then `1/10=10%` of the load is re-distributed across 9 remaining nodes, so per-node workload increase is `(1/10/9)/(1/10) = 1/9 =~ 11%`. - Adding more CPU and RAM to existing `vmstorage` nodes (aka vertical scaling) increases the number of [active time series](https://docs.victoriametrics.com/FAQ.html#what-is-an-active-time-series) the cluster can handle.