[Merged by Bors] - document resource limits

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+### Added
+
+- Default resource requests (memory and cpu) for ZooKeeper pods ([#563]).
+
+[#563]: https://github.com/stackabletech/zookeeper-operator/pull/563
+
 ## [0.11.0] - 2022-09-06
 
 ### Changed

docs/modules/ROOT/pages/usage.adoc

@@ -178,30 +178,14 @@ In the above example, all ZooKeeper nodes in the default group will store data (
 
 By default, in case nothing is configured in the custom resource for a certain role group, each Pod will have a `1Gi` large local volume mount for the data location.
 
-=== Memory requests
+=== Resource Requests
 
-You can request a certain amount of memory for each individual role group as shown below:
+// The "nightly" version is needed because the "include" directive searches for
+// files in the "stable" version by default.
+// TODO: remove the "nightly" version after the next platform release (current: 22.09)
+include::nightly@home:concepts:stackable_resource_requests.adoc[]
 
-[source,yaml]
-----
-servers:
-  roleGroups:
-    default:
-      config:
-        resources:
-          memory:
-            limit: '2Gi'
-----
-
-In this example, each ZooKeeper container in the "default" group will have a maximum of 2 gigabytes of memory. To be more precise, these memory limits apply to the containers running the ZooKeeper daemons but not to any sidecar containers that are part of the pod.
-
-Setting this property will also automatically set the maximum Java heap size for the corresponding process to 80% of the available memory. Be aware that if the memory constraint is too low, the cluster might fail to start. If pods terminate with an 'OOMKilled' status and the cluster doesn't start, try increasing the memory limit.
-
-For more details regarding Kubernetes memory requests and limits see: https://kubernetes.io/docs/tasks/configure-pod-container/assign-memory-resource/[Assign Memory Resources to Containers and Pods].
-
-=== CPU requests
-
-Similarly to memory resources, you can also configure CPU limits, as shown below:
+If no resource requests are configured explicitly, the ZooKeeper operator uses the following defaults:
 
 [source,yaml]
 ----
@@ -210,9 +194,12 @@ servers:
     default:
       config:
         resources:
+          memory:
+            limit: '512Mi'
           cpu:
-            max: '500m'
-            min: '250m'
+            max: '4'
+            min: '500m'
+          storage:
+            data:
+              capacity: '1Gi'
 ----
-
-For more details regarding Kubernetes CPU limits see: https://kubernetes.io/docs/tasks/configure-pod-container/assign-cpu-resource/[Assign CPU Resources to Containers and Pods].

rust/crd/src/lib.rs

@@ -485,11 +485,11 @@ impl ZookeeperCluster {
     fn default_resources() -> Resources<Storage, NoRuntimeLimits> {
         Resources {
             cpu: CpuLimits {
-                min: None,
-                max: None,
+                min: Some(Quantity("500m".to_owned())),
+                max: Some(Quantity("4".to_owned())),
             },
             memory: MemoryLimits {
-                limit: None,
+                limit: Some(Quantity("512Mi".to_owned())),
                 runtime_limits: NoRuntimeLimits {},
             },
             storage: Storage {