CF app JVM memory stress

Last updated on Jun 25, 2026

CF app JVM memory stress is a Cloud Foundry chaos fault that drives sustained memory pressure inside the JVM of one or more instances of a Java-based app. You choose whether the pressure targets the heap or non-heap (metaspace, code cache) via the memoryType tunable. The fault runs for duration seconds and then releases the pressure.

Use this fault to validate the application's behavior near the memory limit: garbage-collection pause times, OutOfMemoryError handling, autoscaling decisions, and downstream consumer experience while the JVM is constrained.

Run your first experiment

If you have not configured the chaos infrastructure yet, go to Quickstart to install the Linux chaos infrastructure and run an experiment end to end.

Use cases

Heap saturation: Test the app's reaction to a near-full heap (latency spikes, GC pressure, OOM events).
Non-heap saturation: Surface class-loading bugs or runaway metaspace consumption.
Autoscaler validation: Confirm memory-based scaling rules trigger correctly.
GC tuning: Identify GC settings that cause excessive pause times under pressure.

Before you begin

Chaos infrastructure: A Linux chaos infrastructure (LCI) installed in one of the supported deployment models.
CF and BOSH credentials: The LCI host has CF_*, UAA_SERVER_ENDPOINT, and BOSH_* credentials configured.
Target identifiers: You know the organization, space, app, and the boshDeployment that manages the cluster.
Java app: The target app is a Java workload exposing a JVM debug agent on port (default 9091).
javaHome: Either JAVA_HOME is set on the container, or you provide javaHome explicitly.

Supported environments

Platform	Support status
Java apps deployed to Cloud Foundry	Supported
Non-Java workloads	Not supported

Permissions required

Action	Requirement
List apps the CF user can access	`SpaceDeveloper`, `SpaceAuditor`, `OrgManager`, or `OrgAuditor`; scopes `cloud_controller.read` or `cloud_controller.admin`
List BOSH deployments	BOSH user with `bosh.read` scope
SSH to a Diego cell via BOSH	BOSH UAA token with `bosh.ssh` or `bosh.admin` scope
Attach the JVM agent to the target container	Operator with `sudo` or root on the cell host

Authentication

Layer	Where to provide	Tunables
Cloud Foundry API + BOSH director	`/etc/linux-chaos-infrastructure/cf.env` on the LCI host	`CF_API_ENDPOINT`, `CF_USERNAME`, `CF_PASSWORD`, `UAA_SERVER_ENDPOINT`, `BOSH_CLIENT`, `BOSH_CLIENT_SECRET`, `BOSH_CA_CERT`, `BOSH_ENVIRONMENT`
vSphere (only when `faultInjectorLocation: vSphere`)	`/etc/linux-chaos-infrastructure/vsphere.env`	`GOVC_URL`, `GOVC_USERNAME`, `GOVC_PASSWORD`, `GOVC_INSECURE`, `VM_NAME`, `VM_USERNAME`, `VM_PASSWORD`

Fault tunables

Required parameters

Tunable	Description	Default
`deploymentModel`	LCI placement model. One of `model-1` or `model-2`.	(required)
`organization`	CF organization that owns the app.	(required)
`space`	CF space within the organization.	(required)
`app`	Java app to stress.	(required)

Chaos parameters

Tunable	Description	Default
`memoryType`	Memory region to fill. One of `heap` or `non-heap`.	`heap`
`port`	JVM agent port inside the container.	`9091`
`javaHome`	Value of `JAVA_HOME`. Not required if the Java binary is on the container's `PATH`.	`""`
`instanceAffectedPercentage`	Percentage of instances to target. `0` targets exactly one.	`0`
`boshDeployment`	BOSH deployment name. Required for `deploymentModel: model-2`.	`""`
`faultInjectorLocation`	`local` or `vSphere`. Required for `deploymentModel: model-2`.	`local`
`faultInjectorPort`	Local port used by the fault-injector.	`50320`
`duration`	Total chaos duration.	`30s`
`skipSSLValidation`	Skip SSL validation when calling CF APIs.	`false`
`rampTime`	Wait period in seconds before and after the fault.	`0`

Tunables that apply to every fault are documented in common tunables for all faults.

Fault execution in brief

Authenticates to Cloud Foundry and BOSH, locates the target app instance(s), attaches an agent to the JVM via the debug port, and allocates memory in the region selected by memoryType until the configured pressure is reached. The pressure is held for duration seconds and released on completion.

Expected behavior during fault execution

JVM heap (or non-heap) utilization climbs toward its limit.
Garbage collection runs more frequently and pause times typically rise.
The app may experience OutOfMemoryError if the configured workload exceeds the limit; the platform may restart the instance.
After the fault ends, memory utilization returns to baseline.

Signals to watch

GC behavior: Inspect JVM GC metrics (pause time, frequency).
Latency: Use an HTTP probe and assert P95 latency stays within SLO.
Instance health: Watch cf app <name> for CRASHED instances during heavy heap pressure.

Recovery and cleanup

The JVM agent is detached when duration elapses, releasing memory.
If the JVM crashed with OutOfMemoryError, Cloud Foundry restarts the instance automatically.

Limitations

Targets the JVM process inside the container, not the host.
Requires the JVM debug port (port) to be reachable inside the container.
non-heap pressure may not always trigger expected behavior if your JVM has high non-heap limits.

Troubleshooting

CF app JVM memory stress fails with 'JAVA_HOME not found' in Harness Chaos Engineering

Set the javaHome tunable to the absolute path of the JDK on the container (for example, /usr/lib/jvm/openjdk). Confirm with cf ssh <app> -c 'echo $JAVA_HOME'.

App keeps crashing during heap stress

If the app crashes repeatedly with OutOfMemoryError, the configured pressure exceeds the heap limit. Reduce duration, decrease the targeted region's size, or increase the app's memory quota with cf scale -m.

Memory does not return to baseline after the experiment

Trigger a full GC with the CF app JVM trigger GC fault, or restage the app: cf restage <app>.

Common configurations

Pressure on non-heap

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-jvm-memory-stress
  labels:
    name: app-jvm-memory-stress
spec:
  cfAppJVMChaos/inputs:
    duration: 60s
    deploymentModel: model-2
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    boshDeployment: cf
    memoryType: non-heap

Stress multiple instances

apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: cf-app-jvm-memory-stress
  labels:
    name: app-jvm-memory-stress
spec:
  cfAppJVMChaos/inputs:
    duration: 30s
    deploymentModel: model-2
    faultInjectorLocation: vSphere
    app: cf-app
    organization: dev-org
    space: dev-space
    boshDeployment: cf
    memoryType: heap
    instanceAffectedPercentage: 50

CF secrets

The following Cloud Foundry secrets reside on the same machine where the chaos infrastructure is executed. These secrets are provided in the /etc/linux-chaos-infrastructure/cf.env file in the following format:

CF_API_ENDPOINT=XXXXXXXXXXXXXXXXXXX
CF_USERNAME=XXXXXXXXXXXXXXXXXXXXXXX
CF_PASSWORD=XXXXXXXXXXXXXXXXXXXXXXX
UAA_SERVER_ENDPOINT=XXXXXXXXXXXXXXX
BOSH_CLIENT=XXXXXXXXXXXXXXXXXXXXXXX
BOSH_CLIENT_SECRET=XXXXXXXXXXXXXXXX
BOSH_CA_CERT=XXXXXXXXXXXXXXXXXXXXXX
BOSH_ENVIRONMENT=XXXXXXXXXXXXXXXXXX

info

If the secrets file is not provided, the secrets are attempted to be derived from environment variables and the config file by the fault-injector.

ENV name	Description	Example
CF_API_ENDPOINT	API endpoint for the CF setup	`https://api.system.cf-setup.com`
CF_USERNAME	Username for the CF user	`username`
CF_PASSWORD	Password for the CF user	`password`
UAA_SERVER_ENDPOINT	API endpoint for the UAA server for the CF setup	`https://uaa.system.cf-setup.com`
BOSH_CLIENT	Used by the `bosh` CLI, the BOSH client	`admin`
BOSH_CLIENT_SECRET	Used by the `bosh` CLI, the BOSH client secret	`UBu9Fu3oW35sO6fw12auPH76gsRTy7`
BOSH_CA_CERT	Used by the `bosh` CLI, the file path for BOSH CA certificate	`/root/root_ca_certificate`
BOSH_ENVIRONMENT	Used by the `bosh` CLI, the BOSH environment	`bosh.corp.local`

Fault injector ENVs and config file

If /etc/linux-chaos-infrastructure/cf.env file is not provided, fault-injector attempts to derive the secrets from environment variables or a configuration file. Any secret that is re-declared will be overridden in the following order of decreasing precedence:

/etc/linux-chaos-infrastructure/cf.env file
Environment variables
Configuration file

The configuration file should be provided at /etc/linux-chaos-infrastructure/cf-fault-injector.yaml:

cf-api-endpoint: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
username: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
password: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
uaa-server-endpoint: XXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-client: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-client-secret: XXXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-ca-cert: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
bosh-environment: XXXXXXXXXXXXXXXXXXXXXXXXXXXXX

A mapping between all the three formats for providing the secrets is as follows:

cf.env	ENV	cf-fault-injector.yaml
CF_API_ENDPOINT	CF_API_ENDPOINT	cf-api-endpoint
CF_USERNAME	USERNAME	username
CF_PASSWORD	PASSWORD	password
UAA_SERVER_ENDPOINT	UAA_SERVER_ENDPOINT	uaa-server-endpoint
BOSH_CLIENT	BOSH_CLIENT	bosh-client
BOSH_CLIENT_SECRET	BOSH_CLIENT_SECRET	bosh-client-secret
BOSH_CA_CERT	BOSH_CA_CERT	bosh-ca-cert
BOSH_ENVIRONMENT	BOSH_ENVIRONMENT	bosh-environment

vSphere secrets

These secrets are provided only if vSphere is used as the deployment platform for CF.

The following vSphere secrets reside on the same machine where the chaos infrastructure is executed. These secrets are provided in the /etc/linux-chaos-infrastructure/vsphere.env file in the following format:

GOVC_URL=XXXXXXXXXXXXXXXXXXXXXX
GOVC_USERNAME=XXXXXXXXXXXXXXXXX
GOVC_PASSWORD=XXXXXXXXXXXXXXXXX
GOVC_INSECURE=XXXXXXXXXXXXXXXXX
VM_NAME=XXXXXXXXXXXXXXXXXXXXXXX
VM_USERNAME=XXXXXXXXXXXXXXXXXXX
VM_PASSWORD=XXXXXXXXXXXXXXXXXXX

ENV Name	Description	Notes
GOVC_URL	Endpoint for vSphere	For example, `192.168.214.244`
GOVC_USERNAME	Username for the vSphere user	For example, `username`
GOVC_PASSWORD	Password for the vSphere user	For example, `password`
GOVC_INSECURE	Skip SSL validation for govc commands	For example, `true`
VM_NAME	Name of the vSphere VM where the fault-injector utility is installed	For example, `cf-vm`
VM_USERNAME	Username for the VM guest user	For example, `root`
VM_PASSWORD	Password for the VM guest user	For example, `password`

CF app JVM CPU stress: Apply CPU pressure instead of memory pressure.
CF app JVM trigger GC: Force a GC cycle to test pause-time behavior.

Use cases​

Before you begin​

Supported environments​

Permissions required​

Authentication​

Fault tunables​

Fault execution in brief​

Expected behavior during fault execution​

Signals to watch​

Recovery and cleanup​

Limitations​

Troubleshooting​

Common configurations​

Pressure on non-heap​

Stress multiple instances​

CF secrets​

Fault injector ENVs and config file​

vSphere secrets​

Related faults​