Pod JVM trigger gc

Pod JVM trigger gc triggers the garbage collector for a Java process executing in a Kubernetes pod. This causes unused (or out of scope) objects and variables to be garbage collected and recycled, thereby freeing up memory space.

tip

JVM chaos faults use the Byteman utility to inject chaos faults into the JVM.

Use cases

Pod JVM trigger gc:

• Determines how the application behaves when memory space is freed up randomly for a brief period.
• Determines how efficiently an application recovers and returns to normalcy.

Optional tunables

Tunable	Description	Notes
TOTAL_CHAOS_DURATION	Duration through which chaos is injected into the target resource. Should be provided in [numeric-hours]h[numeric-minutes]m[numeric-seconds]s format.	Default: 30s. Examples: 1m25s, 1h3m2s, 1h3s. For more information, go to duration of the chaos.
POD_AFFECTED_PERC	Percentage of total pods to target. Provide numeric values.	Default: 0 (corresponds to 1 replica). For more information, go to pods affected percentage
JAVA_HOME	Path to the Java installation directory.	For example, /tmp/dir/jdk.
BYTEMAN_PORT	Port used by the Byteman agent.	Default: 9091.
CONTAINER_RUNTIME	Container runtime interface for the cluster	Default: containerd. Support values: docker, containerd and crio. For more information, go to container runtime.
SOCKET_PATH	Path of the containerd or crio or docker socket file.	Default: /run/containerd/containerd.sock. For more information, go to socket path.
RAMP_TIME	Period to wait before and after injecting chaos. Should be provided in [numeric-hours]h[numeric-minutes]m[numeric-seconds]s format.	Default: 0s. Examples: 1m25s, 1h3m2s, 1h3s. For more information, go to ramp time.
SEQUENCE	Sequence of chaos execution for multiple target pods.	Default: parallel. Supports serial and parallel. For more information, go to sequence of chaos execution.
TARGET_CONTAINER	Name of the container subject to API header modification.	None. For more information, go to target specific container
TARGET_PODS	Comma-separated list of application pod names subject to pod HTTP modify body.	If not provided, the fault selects target pods randomly based on provided appLabels. For more information, go to target specific pods.
NODE_LABEL	Node label used to filter the target node if TARGET_NODE environment variable is not set.	It is mutually exclusive with the TARGET_NODE environment variable. If both are provided, the fault uses TARGET_NODE. For more information, go to node label.
LIB_IMAGE	Image used to inject chaos.	Default: harness/chaos-go-runner:main-latest. For more information, go to image used by the helper pod.

Parameters

The following YAML snippet illustrates the use of these tunables:

apiVersion: litmuschaos.io/v1alpha1
kind: KubernetesChaosExperiment
metadata:
  name: pod-jvm-trigger-gc
  namespace: hce
          env:
            - name: TOTAL_CHAOS_DURATION
              value: "60"
            - name: POD_AFFECTED_PERCENTAGE
              value: ""
            - name: BYTEMAN_PORT
              value: "9091"
            - name: JAVA_HOME
              value: ""
            - name: CONTAINER_RUNTIME
              value: containerd
            - name: SOCKET_PATH
              value: /run/containerd/containerd.sock
            - name: LIB_IMAGE
              value: docker.io/harness/chaos-ddcr-faults:1.49.2
            - name: RAMP_TIME
              value: ""
            - name: SEQUENCE
              value: parallel
            - name: TARGET_CONTAINER
              value: ""
            - name: TARGET_PODS
              value: ""
            - name: NODE_LABEL
              value: ""