Merge pull request #86885 from mburke5678/nodes-eviction-pressure

OCPBUGS48047 As per the document it does not states that 'evictionPressureTransitionPeriod configuration' cannot be set to '0s'.

Author: mburke5678

modules/microshift-low-latency-config-yaml.adoc

@@ -44,7 +44,7 @@ kubelet: <1>
     memory.available: "100Mi" # <9>
     nodefs.available: "10%" # <10>
     nodefs.inodesFree: "5%" # <11>
-  evictionPressureTransitionPeriod: 0s
+  evictionPressureTransitionPeriod: 5m <12>
 # ...
 ----
 <1> If you change the CPU or memory managers in the kubelet configuration, you must remove files that cache the previous configuration. Restart the host to remove them automatically, or manually remove the `/var/lib/kubelet/cpu_manager_state` and `/var/lib/kubelet/memory_manager_state` files.
@@ -58,6 +58,7 @@ kubelet: <1>
 <9> In this example, the `evictionHard.memory.available` parameter means that the pods are evicted when the available memory of the node drops below 100MiB.
 <10> In this example, the `evictionHard.nodefs.available` parameter means that the pods are evicted when the main filesystem of the node has less than 10% available space.
 <11> In this example, the `evictionHard.nodefs.inodesFree` parameter means that the pods are evicted when more than 15% of the node's main filesystem's inodes are in use.
+<12> For container garbage collection: The duration to wait before transitioning out of an eviction pressure condition. Setting the `evictionPressureTransitionPeriod` parameter to `0` configures the default value of 5 minutes.
 
 .Verification
 
@@ -68,4 +69,4 @@ kubelet: <1>
 . Tune your operating system. For example, configure and activate a TuneD profile.
 . Optional: Configure automatic enablement of your TuneD profile.
 . Optional: If you are using the x86_64 architecture, you can install {op-system-rt-kernel}.
-. Prepare your {microshift-short} workloads for low latency.
+. Prepare your {microshift-short} workloads for low latency.

modules/microshift-low-latency-install-kernelrt-rhel-edge.adoc

@@ -60,7 +60,7 @@ kubelet:
     memory.available: 100Mi
     nodefs.available: 10%
     nodefs.inodesFree: 5%
-  evictionPressureTransitionPeriod: 0s
+  evictionPressureTransitionPeriod: 5m
 """
 
 [[customizations.files]]
@@ -88,4 +88,4 @@ reboot_after_apply: True
 . Complete the image building process.
 . If you have not completed the previous steps for enabling low latency for your {microshift-short} cluster, do so now. Update the blueprint with the information gathered in those steps.
 . If you have not configured workload partitioning, do so now.
-. Prepare your {microshift-short} workloads for low latency.
+. Prepare your {microshift-short} workloads for low latency.

modules/microshift-low-latency-rhel-edge-blueprint-rtk.adoc

@@ -79,7 +79,7 @@ kubelet:
     memory.available: 100Mi
     nodefs.available: 10%
     nodefs.inodesFree: 5%
-  evictionPressureTransitionPeriod: 0s
+  evictionPressureTransitionPeriod: 5m
 """
 
 [[customizations.files]]
@@ -101,4 +101,4 @@ data = """
 profile: microshift-baseline
 reboot_after_apply: True
 """
-----
+----

modules/nodes-nodes-garbage-collection-configuring.adoc

@@ -102,7 +102,7 @@ spec:
       nodefs.inodesFree: "4%"
       imagefs.available: "10%"
       imagefs.inodesFree: "5%"
-    evictionPressureTransitionPeriod: 0s <7>
+    evictionPressureTransitionPeriod: 3m <7>
     imageMinimumGCAge: 5m <8>
     imageGCHighThresholdPercent: 80 <9>
     imageGCLowThresholdPercent: 75 <10>
@@ -115,7 +115,7 @@ spec:
 <5> For container garbage collection: Grace periods for the soft eviction. This parameter does not apply to `eviction-hard`.
 <6> For container garbage collection: Eviction thresholds based on a specific eviction trigger signal.
 For `evictionHard` you must specify all of these parameters.  If you do not specify all parameters, only the specified parameters are applied and the garbage collection will not function properly.
-<7> For container garbage collection: The duration to wait before transitioning out of an eviction pressure condition.
+<7> For container garbage collection: The duration to wait before transitioning out of an eviction pressure condition. Setting the `evictionPressureTransitionPeriod` parameter to `0` configures the default value of 5 minutes.
 <8> For image garbage collection: The minimum age for an unused image before the image is removed by garbage collection.
 <9> For image garbage collection: The percent of disk usage (expressed as an integer) that triggers image garbage collection.
 <10> For image garbage collection: The percent of disk usage (expressed as an integer) that image garbage collection attempts to free.

modules/nodes-nodes-garbage-collection-containers.adoc

@@ -41,4 +41,9 @@ For `evictionHard` you must specify all of these parameters.  If you do not spec
 
 If a node is oscillating above and below a soft eviction threshold, but not exceeding its associated grace period, the corresponding node would constantly oscillate between `true` and `false`. As a consequence, the scheduler could make poor scheduling decisions.
 
-To protect against this oscillation, use the `eviction-pressure-transition-period` flag to control how long {product-title} must wait before transitioning out of a pressure condition. {product-title} will not set an eviction threshold as being met for the specified pressure condition for the period specified before toggling the condition back to false.
+To protect against this oscillation, use the `evictionpressure-transition-period` flag to control how long {product-title} must wait before transitioning out of a pressure condition. {product-title} will not set an eviction threshold as being met for the specified pressure condition for the period specified before toggling the condition back to false.
+
+[NOTE]
+====
+Setting the `evictionPressureTransitionPeriod` parameter to `0` configures the default value of 5 minutes. You cannot set an eviction pressure transition period to zero seconds. 
+====