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Redis cache expire

Redis cache expire expires a given key (or all keys) for a specified duration. During this period of chaos, you can't access the keys associated with the cache.

Pod Redis cache expire

Use cases​

Redis cache expire determines the resilience of Redis-dependant applications against frequent cache expiry.

Redis authentication​

note

If your Redis server doesn't require authentication, you can directly provide the ADDRESS tunable, that refers to the Redis server address. Refer here.

If your application requires a secret or authentication, provide the ADDRESS, PASSWORD and the TLS authentication certificate. Create a Kubernetes secret (say redis-secret) in the namespace where the fault executes. A sample is shown below.

apiVersion: v1
kind: Secret
metadata:
  name: redis-secret  # Name of the Secret
type: Opaque       # Default Secret type
stringData:
  redis-secret.yaml: |-
    address: 34.136.111.6:6379
    password: mypass
    tlsCertFile: <cert>

After creating the secret, mount the secret into the experiment, and reference the mounted file path using the SECRET_FILE_PATH environment variable in the experiment manifest. A sample is shown below.

apiVersion: litmuschaos.io/v1alpha1
kind: K8sFault
metadata:
  name: redis-cache-penetration
spec:
  definition:
    chaos:
      env:
        ...  # other env
        ...  # other env
        - name: SECRET_FILE_PATH
          value: "/tmp/redis-secret.yaml"
      components:
        secrets:   # Kubernetes secret mounted
          - name: redis-secret
            mountPath: /tmp/

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.
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.
ADDRESS The address of the Redis server. If your Redis server doesn't require authentication, directly provide the address.
KEY The key to expire in the Redis cache. For empty value, all the keys are expired. For more information, go to key.
DATABASE Redis database where the key exists. Default: 0.
EXPIRATION The duration after which the key expires. Default: 0.
EXPIRY_OPTION The options to expire a Redis key. Refer here for more information. Supports one of: NX, XX, GT and LT.
SECRET_FILE_PATH Path to the file that contains the secret. If a password or certificate is required alongside the address, use the secret file approach.

Parameters​

The following YAML snippet illustrates the use of these tunables:

apiVersion: litmuchaos.io/v1alpha1
kind: K8sFault
metadata:
  name: redis-cache-expire
      env:
        - name: TOTAL_CHAOS_DURATION
          value: "60" # in seconds
        - name: RAMP_TIME
          value: ""
        - name: ADDRESS
          value: ""
        - name: KEY
          value: ""
        - name: DATABASE
          value: "0"
        - name: EXPIRATION
          value: ""
        - name: EXPIRY_OPTION
          value: ""
        - name: SECRET_FILE_PATH  # optional- required only for authentication
          value: /tmp/redis-secret.yaml