From 62bc01e77810bc470017e9d7885dca35e3f9ccdb Mon Sep 17 00:00:00 2001
From: abrennan89 <abrennan@redhat.com>
Date: Mon, 18 Sep 2023 10:16:40 -0500
Subject: [PATCH] OBSDOCS-214: Documenting Loki restart behavior

---
 logging/cluster-logging-loki.adoc           | 6 ++++++
 modules/logging-loki-restart-hardening.adoc | 9 +++++++++
 2 files changed, 15 insertions(+)
 create mode 100644 modules/logging-loki-restart-hardening.adoc

diff --git a/logging/cluster-logging-loki.adoc b/logging/cluster-logging-loki.adoc
index a1e7476af4..fe6622a199 100644
--- a/logging/cluster-logging-loki.adoc
+++ b/logging/cluster-logging-loki.adoc
@@ -13,7 +13,13 @@ Loki is a horizontally scalable, highly available, multi-tenant log aggregation
 include::modules/loki-deployment-sizing.adoc[leveloffset=+1]
 
 include::modules/cluster-logging-loki-deploy.adoc[leveloffset=+1]
+////
+include::modules/logging-loki-restart-hardening.adoc[leveloffset=+1]
 
+[role="_additional-resources"]
+.Additional resources
+* link:https://kubernetes.io/docs/concepts/workloads/pods/disruptions/#pod-disruption-budgets[Pod disruption budgets Kubernetes documentation]
+////
 include::modules/logging-loki-retention.adoc[leveloffset=+1]
 
 include::modules/cluster-logging-forwarding-lokistack.adoc[leveloffset=+1]
diff --git a/modules/logging-loki-restart-hardening.adoc b/modules/logging-loki-restart-hardening.adoc
new file mode 100644
index 0000000000..180b1636dc
--- /dev/null
+++ b/modules/logging-loki-restart-hardening.adoc
@@ -0,0 +1,9 @@
+// Module included in the following assemblies:
+//
+// * logging/cluster-logging-loki.adoc
+
+:_content-type: CONCEPT
+[id="logging-loki-restart-hardening_{context}"]
+= LokiStack behavior during cluster restarts
+
+In logging version 5.8 and newer versions, when an {product-title} cluster is restarted, LokiStack ingestion and the query path continue to operate within the available CPU and memory resources available for the node. This means that there is no downtime for the LokiStack during {product-title} cluster updates. This behavior is achieved by using `PodDisruptionBudget` resources. The Loki Operator provisions `PodDisruptionBudget` resources for Loki, which determine the minimum number of pods that must be available per component to ensure normal operations under certain conditions.