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VMware HTTP reset peer

VMware HTTP reset peer injects HTTP reset chaos that stops the outgoing HTTP requests by resetting the TCP connection for the requests.

  • The service whose port is affected is specified using the TARGET_SERVICE_PORT environment variable.
  • It tests the application's resilience to lossy (or flaky) HTTP connections.

VMware HTTP Reset Peer

Usage​

View the uses of the fault
This fault helps determine how resilient an application is when outgoing HTTP requests are halted unexpectly. It determines how quickly and efficiently an application recovers from these unexpected halts. It simulates premature connection loss (firewall issues or other issues) between microservices (verify connection timeout), and connection resets due to resource limitations on the server side like out of memory server (or process killed or overload on the server due to a high amount of traffic).

Prerequisites​

  • Kubernetes >= 1.17
  • Vcenter access to stop and start the VM.
  • Kubernetes secret that has the Vcenter credentials in the CHAOS_NAMESPACE. Below is a sample secret file:
apiVersion: v1
kind: Secret
metadata:
    name: vcenter-secret
    namespace: litmus
type: Opaque
stringData:
    VCENTERSERVER: XXXXXXXXXXX
    VCENTERUSER: XXXXXXXXXXXXX
    VCENTERPASS: XXXXXXXXXXXXX

Note​

You can pass the VM credentials as secrets or as a ChaosEngine environment variable.

Default validations​

The VM should be in a healthy state.

Fault tunables​

Fault tunables

Mandatory fields

Variables Description Notes
VM_NAME Name of the VMware VM. For example, test-vm.
VM_USER_NAME Username with sudo privileges. For example, vm-user.
VM_PASSWORD User password. For example, 1234.
RESET_TIMEOUT It specifies the duration after which the connect is reset. Defaults to 0.
TARGET_SERVICE_PORT Service port to target Defaults to port 80.

Optional Fields

Variables Description Notes
TOTAL_CHAOS_DURATION Duration that you specify, through which chaos is injected into the target resource (in seconds). Defaults to 30s.
CHAOS_INTERVAL Time interval between two successive instance terminations (in seconds). Defaults to 30s.
SEQUENCE Sequence of chaos execution for multiple instances. Defaults to parallel. Supports serial sequence as well.
RAMP_TIME Period to wait before and after injecting chaos (in seconds). For example, 30s.
INSTALL_DEPENDENCY Specify whether you wish to install the dependency to run the experiment. Defaults to true. If the dependency already exists, you can turn it off.
PROXY_PORT Port where the proxy listens for requests. Defaults to 20000.
TOXICITY Percentage of HTTP requests that are affected. Defaults to 100.
NETWORK_INTERFACE Network interface used for the proxy. Defaults to eth0.

Fault examples​

Common fault tunables​

Refer to the common attributes to tune the common tunables for all the faults.

Target service port​

It defines the port of the target service. You can tune it using the TARGET_SERVICE_PORT environment variable.

Use the following example to tune it:

## provide the port of the targeted service
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: VMware-http-reset-peer
    spec:
      components:
        env:
        # provide the port of the targeted service
        - name: TARGET_SERVICE_PORT
          value: "80"

Proxy port​

It defines the port where proxy server listens for requests. You can tune it using the PROXY_PORT environment variable.

Use the following example to tune it:

# provide the port for proxy server
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: VMware-http-reset-peer
    spec:
      components:
        env:
        # provide the port for proxy server
        - name: PROXY_PORT
          value: '8080'
        # provide the port of the targeted service
        - name: TARGET_SERVICE_PORT
          value: "80"

Reset timeout​

It defines the reset timeout value that is added to the HTTP request. You can tune it using the RESET_TIMEOUT environment variable.

Use the following example to tune it:

## provide the reset timeout value
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: VMware-http-reset-peer
    spec:
      components:
        env:
        # reset timeout specifies after how much duration to reset the connection
        - name: RESET_TIMEOUT #in ms
          value: '2000'
        # provide the port of the targeted service
        - name: TARGET_SERVICE_PORT
          value: "80"

Toxicity​

It defines the toxicity value, i.e the percentage of the total number of HTTP requests that are affected. You can tune it using the TOXICITY environment variable.

Use the following example to tune it:

## provide the toxicity
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: VMware-http-reset-peer
    spec:
      components:
        env:
        # toxicity is the probability of the request to be affected
        # provide the percentage value in the range of 0-100
        # 0 means no request will be affected and 100 means all request will be affected
        - name: TOXICITY
          value: "100"
        # provide the port of the targeted service
        - name: TARGET_SERVICE_PORT
          value: "80"

Network interface​

It defines the network interface that is used for the proxy. You can tune it using the NETWORK_INTERFACE environment variable.

Use the following example to tune it:

## provide the network interface for proxy
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: VMware-http-reset-peer
    spec:
      components:
        env:
        # provide the network interface for proxy
        - name: NETWORK_INTERFACE
          value: "eth0"
        # provide the port of the targeted service
        - name: TARGET_SERVICE_PORT
          value: '80'