docs: Document graceful shutdown (#306)

* docs: Document graceful shutdown

* changelog

* wording

* remove duplicated nav entry

CHANGELOG.md

@@ -11,6 +11,7 @@ All notable changes to this project will be documented in this file.
 - Support PodDisruptionBudgets for HistoryServer ([#288]).
 - Support for versions 3.4.1, 3.5.0 ([#291]).
 - History server now exports metrics via jmx exporter (port 18081) ([#291]).
+- Document graceful shutdown  ([#306]).
 
 ### Changed
 
@@ -43,6 +44,7 @@ All notable changes to this project will be documented in this file.
 [#291]: https://github.com/stackabletech/spark-k8s-operator/pull/291
 [#297]: https://github.com/stackabletech/spark-k8s-operator/pull/297
 [#302]: https://github.com/stackabletech/spark-k8s-operator/pull/302
+[#306]: https://github.com/stackabletech/spark-k8s-operator/pull/306
 
 ## [23.7.0] - 2023-07-14
 

docs/modules/spark-k8s/pages/usage-guide/operations/graceful-shutdown.adoc

@@ -0,0 +1,6 @@
+= Graceful shutdown
+
+Normally you can configure the graceful shutdown as described in xref:concepts:operations/graceful_shutdown.adoc[].
+
+However, the spark-k8s operator does not implement any graceful shutdown mechanism, as the driver and executor Pods are created by Spark itself.
+So it's Spark responsibility to handle the shutdown and recovery of Pods.

docs/modules/spark-k8s/partials/nav.adoc

@@ -9,7 +9,8 @@
 ** xref:spark-k8s:usage-guide/s3.adoc[]
 ** xref:spark-k8s:usage-guide/history-server.adoc[]
 ** xref:spark-k8s:usage-guide/examples.adoc[]
-* xref:spark-k8s:usage-guide/operations/index.adoc[]
-* xref:spark-k8s:usage-guide/operations/pod-placement.adoc[]
-* xref:spark-k8s:usage-guide/operations/pod-disruptions.adoc[]
+** xref:spark-k8s:usage-guide/operations/index.adoc[]
+*** xref:spark-k8s:usage-guide/operations/pod-placement.adoc[]
+*** xref:spark-k8s:usage-guide/operations/pod-disruptions.adoc[]
+*** xref:spark-k8s:usage-guide/operations/graceful-shutdown.adoc[]
 * xref:spark-k8s:crd-reference.adoc[]