From d2a63f334cfb1e9b921239f9624945b1ea5850be Mon Sep 17 00:00:00 2001 From: Felix Kunde <felix-kunde@gmx.de> Date: Mon, 17 Jun 2019 17:39:00 +0200 Subject: [PATCH] address review comments --- docs/administrator.md | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/docs/administrator.md b/docs/administrator.md index caf82af6..1b51091f 100644 --- a/docs/administrator.md +++ b/docs/administrator.md @@ -158,15 +158,17 @@ data: By default the operator uses a PodDisruptionBudget (PDB) to protect the cluster from voluntarily disruptions and hence unwanted DB downtime. The `MinAvailable` -parameter of the PDB is set to `1` which makes it work for single-node clusters -or in situations when there is no master (e.g. standby clusters). +parameter of the PDB is set to `1` which prevents killing masters in single-node +clusters and/or the last remaining running instance in a multi-node cluster. The PDB is only relaxed in two scenarios: * If a cluster is scaled down to `0` instances (e.g. for draining nodes) * If the PDB is disabled in the configuration (`enable_pod_disruption_budget`) The PDB is still in place having `MinAvailable` set to `0`. If enabled it will -be automatically set to `1` on scale up. +be automatically set to `1` on scale up. Disabling PDBs helps avoiding blocking +Kubernetes upgrades in managed K8s environments at the cost of prolonged DB +downtime. See PR #384 for the use case. ### Add cluster-specific labels -- GitLab