From 3c8de0db371b7401dc82e6ed1b2fd8b6d621c332 Mon Sep 17 00:00:00 2001
From: Henning Andersen <33268011+henningandersen@users.noreply.github.com>
Date: Thu, 15 Apr 2021 15:35:12 +0200
Subject: [PATCH] Autoscaling frozen shards docs (#71583)

Added documentation for the frozen shards decider.

Relates #71042
---
 .../autoscaling/autoscaling-deciders.asciidoc    |  5 +++++
 .../deciders/frozen-shards-decider.asciidoc      | 16 ++++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 docs/reference/autoscaling/deciders/frozen-shards-decider.asciidoc

diff --git a/docs/reference/autoscaling/autoscaling-deciders.asciidoc b/docs/reference/autoscaling/autoscaling-deciders.asciidoc
index cebb3f867a99d..e6cc43c81d403 100644
--- a/docs/reference/autoscaling/autoscaling-deciders.asciidoc
+++ b/docs/reference/autoscaling/autoscaling-deciders.asciidoc
@@ -11,6 +11,10 @@ governing data nodes.
 Estimates required storage capacity based on current ingestion into hot nodes.
 Available for policies governing hot data nodes.
 
+<<autoscaling-frozen-shards-decider,Frozen shards decider>>::
+Estimates required memory capacity based on number of frozen shards.
+Available for policies governing frozen data nodes.
+
 <<autoscaling-machine-learning-decider,Machine learning decider>>::
 Estimates required memory capacity based on machine learning jobs.
 Available for policies governing machine learning nodes.
@@ -20,5 +24,6 @@ Responds with a fixed required capacity. This decider is intended for testing on
 
 include::deciders/reactive-storage-decider.asciidoc[]
 include::deciders/proactive-storage-decider.asciidoc[]
+include::deciders/frozen-shards-decider.asciidoc[]
 include::deciders/machine-learning-decider.asciidoc[]
 include::deciders/fixed-decider.asciidoc[]
diff --git a/docs/reference/autoscaling/deciders/frozen-shards-decider.asciidoc b/docs/reference/autoscaling/deciders/frozen-shards-decider.asciidoc
new file mode 100644
index 0000000000000..9308715725a77
--- /dev/null
+++ b/docs/reference/autoscaling/deciders/frozen-shards-decider.asciidoc
@@ -0,0 +1,16 @@
+[role="xpack"]
+[[autoscaling-frozen-shards-decider]]
+=== Frozen shards decider
+
+The frozen shards decider (`frozen_shards`) calculates the memory required to search
+the current frozen tier data set. Based on a required memory amount per shard, it
+calculates the necessary memory in the frozen tier.
+
+[[autoscaling-frozen-shards-decider-settings]]
+==== Configuration settings
+
+`memory_per_shard`::
+(Optional, <<byte-units,byte value>>)
+The memory needed per shard, in bytes. Defaults to 2000 shards per 64 GB node (roughly 32 MB per shard).
+Notice that this is total memory, not heap, assuming that the Elasticsearch default heap sizing
+mechanism is used and that nodes are not bigger than 64 GB.