RDS instance delete

Introduction

RDS instance delete removes an instances from AWS RDS cluster. This makes the cluster unavailable for a specific duration.

Use cases

RDS instance delete determines how quickly an application can recover from an unexpected RDS cluster deletion.

note

• Kubernetes version 1.17 or later is required to execute this fault.
• AWS access to delete RDS instances.
• The RDS instance must be in a healthy state.
• Kubernetes secret must have the AWS access configuration(key) in the CHAOS_NAMESPACE. A sample secret file looks like:

  apiVersion: v1
  kind: Secret
  metadata:
    name: cloud-secret
  type: Opaque
  stringData:
    cloud_config.yml: |-
      # Add the cloud AWS credentials respectively
      [default]
      aws_access_key_id = XXXXXXXXXXXXXXXXXXX
      aws_secret_access_key = XXXXXXXXXXXXXXX
• Harness recommends using the same secret name, that is, cloud-secret. Otherwise, you must update the AWS_SHARED_CREDENTIALS_FILE environment variable in the fault template and you won't be able to use the default health check probes.
• Go to superset permission/policy to execute all AWS faults.
• Go to the common tunables and AWS-specific tunables to tune the common tunables for all faults and AWS-specific tunables.
• Go to AWS named profile for chaos to use a different profile for AWS faults.

Below is an example AWS policy to execute the fault.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeInstanceStatus",
                "ec2:DescribeInstances",
                "rds:DescribeDBClusters",
                "rds:DescribeDBInstances",
                "rds:DeleteDBInstance"
            ],
            "Resource": "*"
        }
    ]
}

Fault tunables

Mandatory tunables

Tunable	Description	Notes
CLUSTER_NAME	Name of the target RDS cluster	For example, rds-cluster-1
RDS_INSTANCE_IDENTIFIER	Name of the target RDS Instances	For example, rds-cluster-1-instance
REGION	The region name of the target RDS cluster	For example, us-east-1

Optional tunables

Tunable	Description	Notes
TOTAL_CHAOS_DURATION	Duration that you specify, through which chaos is injected into the target resource (in seconds).	Default: 30 s
INSTANCE_AFFECTED_PERC	The Percentage of total RDS instance that are part of RDS cluster to target	Default: 0 (corresponds to 1 instance). Provide numeric values only.
SEQUENCE	It defines sequence of chaos execution for multiple instance	Default value: parallel. Supported: serial, parallel
AWS_SHARED_CREDENTIALS_FILE	Provide the path for AWS secret credentials	Default: /tmp/cloud_config.yml
RAMP_TIME	Period to wait before and after injection of chaos in sec	For example, 30 s

RDS cluster name

Cluster name of the target RDS cluster. Tune it by using the CLUSTER_NAME environment variable. If this variable is not provided, the fault selects the Instance Identifier.

The following YAML snippet illustrates the use of this environment variable:

# delete the RDS instance
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: rds-instance-delete
    spec:
      components:
        env:
        # provide the name of RDS cluster
        - name: CLUSTER_NAME
          value: 'rds-demo-cluster'
        - name: REGION
          value: 'us-east-2'
        - name: TOTAL_CHAOS_DURATION
          value: '60'

RDS instance identifier

RDS instance name. Tune it by using the RDS_INSTANCE_IDENTIFIER environment variable.

The following YAML snippet illustrates the use of this environment variable:

# delete the RDS instance
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: rds-instance-delete
    spec:
      components:
        env:
        # provide the RDS instance identifier 
        - name: RDS_INSTANCE_IDENTIFIER
          value: 'rds-demo-instance-1,rds-demo-instance-2'
        - name: INSTANCE_AFFECTED_PERC
          value: '100'
        - name: REGION
          value: 'us-east-2'
        - name: TOTAL_CHAOS_DURATION
          value: '60'