Merge pull request #7921 from mosbahmajed/workitem-85945

AB#3203: Workitem 85945 - AKS DocReview: Increased memory usage reported in Kubernetes 1.25 or later versions

Author: AmandaAZ

support/azure/azure-kubernetes/create-upgrade-delete/aks-increased-memory-usage-cgroup-v2.md

@@ -1,8 +1,8 @@
 ---
 title: Increased memory usage reported in Kubernetes 1.25 or later versions
 description: Resolve an increase in memory usage that's reported after you upgrade an Azure Kubernetes Service (AKS) cluster to Kubernetes 1.25.x.
-ms.date: 07/13/2023
-editor: v-jsitser
+ms.date: 03/03/2025
+editor: momajed
 ms.reviewer: aritraghosh, cssakscic, v-leedennis
 ms.service: azure-kubernetes-service
 ms.custom: sap:Create, Upgrade, Scale and Delete operations (cluster or nodepool)
@@ -23,23 +23,49 @@ You experience one or more of the following symptoms:
 
 ## Cause
 
-This increase is caused by a change in memory accounting within version 2 of the Linux control group (cgroup) API. [Cgroup v2](https://kubernetes.io/docs/concepts/architecture/cgroups/) is now the default cgroup version for Kubernetes 1.25 on AKS.
+This increase is caused by a change in memory accounting within version 2 of the Linux control group (`cgroup`) API. [Cgroup v2](https://kubernetes.io/docs/concepts/architecture/cgroups/) is now the default `cgroup` version for Kubernetes 1.25 on AKS.
 
 > [!NOTE]  
-> This issue is distinct from the memory saturation in nodes that's caused by applications or frameworks that aren't aware of cgroup v2. For more information, see [Memory saturation occurs in pods after cluster upgrade to Kubernetes 1.25](./aks-memory-saturation-after-upgrade.md).
+> This issue is distinct from the memory saturation in nodes that's caused by applications or frameworks that aren't aware of `cgroup` v2. For more information, see [Memory saturation occurs in pods after cluster upgrade to Kubernetes 1.25](./aks-memory-saturation-after-upgrade.md).
 
 ## Solution
 
 - If you observe frequent memory pressure on the nodes, upgrade your subscription to increase the amount of memory that's available to your virtual machines (VMs).
 
 - If you see a higher eviction rate on the pods, [use higher limits and requests for pods](/azure/aks/developer-best-practices-resource-management#define-pod-resource-requests-and-limits).
 
+- `cgroup` v2 uses a different API than `cgroup` v1. If there are any applications that directly access the `cgroup` file system, update them to later versions that support `cgroup` v2. For example:
+
+  - **Third-party monitoring and security agents**:
+
+     Some monitoring and security agents depend on the `cgroup` file system. Update these agents to versions that support `cgroup` v2.
+
+  - **Java applications**:
+
+     Use versions that fully support `cgroup` v2:
+    - OpenJDK/HotSpot: `jdk8u372`, `11.0.16`, `15`, and later versions.
+    - IBM Semeru Runtimes: `8.0.382.0`, `11.0.20.0`, `17.0.8.0`, and later versions.
+    - IBM Java: `8.0.8.6` and later versions.
+
+  - **uber-go/automaxprocs**:  
+    If you're using the `uber-go/automaxprocs` package, ensure the version is `v1.5.1` or later.
+
+- An alternative temporary solution is to revert the `cgroup` version on your nodes by using the DaemonSet. For more information, see [Revert to cgroup v1 DaemonSet](https://github.com/Azure/AKS/blob/master/examples/cgroups/revert-cgroup-v1.yaml).
+
+> [!IMPORTANT]
+> - Use the DaemonSet cautiously. Test it in a lower environment before applying to production to ensure compatibility and prevent disruptions.
+> - By default, the DaemonSet applies to all nodes in the cluster and reboots them to implement the `cgroup` change.  
+> - To control how the DaemonSet is applied, configure a `nodeSelector` to target specific nodes.
+
+
 > [!NOTE]  
 > If you experience only an increase in memory use without any of the other symptoms that are mentioned in the "Symptoms" section, you don't have to take any action.
 
 ## Status
 
-We're actively working with the Kubernetes community to fix the underlying issue, and we'll keep you updated on our progress. We also plan to change the eviction thresholds or [resource reservations](/azure/aks/concepts-clusters-workloads#resource-reservations), depending on the outcome of the fix.
+We're actively working with the Kubernetes community to resolve the underlying issue. Progress on this effort can be tracked at [Azure/AKS Issue #3443](https://github.com/kubernetes/kubernetes/issues/118916). 
+
+As part of the resolution, we plan to adjust the eviction thresholds or update [resource reservations](/azure/aks/concepts-clusters-workloads#resource-reservations), depending on the outcome of the fix.
 
 ## Reference