You have a Standard Tier Memorystore for Redis instance deployed in a production environment. You need to simulate a Redis instance failover in the most accurate disaster recovery situation, and ensure that the failover has no impact on production data. What should you do?
To simulate a Redis instance failover accurately and ensure it has no impact on production data, the best approach is to create a Standard Tier Memorystore for Redis instance in a development environment and initiate a manual failover using the force-data-loss data protection mode. Testing in a development environment ensures that any potential data loss or service interruption does not affect the production environment. The force-data-loss mode provides a rigorous test by not checking the synchronization state between the primary and replicas, thereby simulating a more comprehensive failover scenario.
The best option is B - Create a Standard Tier Memorystore for Redis instance in a development environment. Initiate a manual failover by using the force-data-loss data protection mode. The key points are: • The failover should be tested in a separate development environment, not production, to avoid impacting real data. • The force-data-loss mode will simulate a full failover and restart, which is the most accurate test of disaster recovery. • Limited-data-loss mode only fails over reads which does not fully test write capabilities. • Increasing replicas in production and failing over (C) risks losing real production data. • Failing over production (D) also risks impacting real data and traffic. So option B isolates the test from production and uses the most rigorous failover mode to fully validate disaster recovery capabilities.
Separate Development Environment: Isolates testing from production, preventing any impact on live data or services. Provides a safe and controlled environment for simulating failover scenarios.
Increasing the number of replicas in a Redis instance in a production environment means that we will have additional copies of the same data and thats why failover will not impact the production data
"no impact on production data" - not C nor D
Best option is B - no impact on production env and forces a full failover
B. Create a Standard Tier Memorystore for Redis instance in a development environment. Initiate a manual failover by using the force-data-loss data protection mode
https://cloud.google.com/memorystore/docs/redis/about-manual-failover
D seems correct. We are required to simulate and not test in a different environment. "How data protection modes work The limited-data-loss mode minimizes data loss by verifying that the difference in data between the primary and replica is below 30 MB before initiating the failover. The offset on the primary is incremented for each byte of data that must be synchronized to its replicas. In the limited-data-loss mode, the failover will abort if the greatest offset delta between the primary and each replica is 30MB or greater. If you can tolerate more data loss and want to aggressively execute the failover, try setting the data protection mode to force-data-loss. The force-data-loss mode employs a chain of failover strategies to aggressively execute the failover. It does not check the offset delta between the primary and replicas before initiating the failover; you can potentially lose more than 30MB of data changes."