The 'elasticache memcached failover' error occurs when there is a failure in the Elasticache Memcached cluster. Elasticache is AWS's fully-managed in-memory data store, and Memcached is one of the available caching engines for it. Failover happens when the primary node of a Memcached cluster fails, and the secondary (replica) node automatically takes over. During the failover process, there might be a temporary unavailability of the cache service, which can cause the 'elasticache memcached failover' error.
To resolve the 'elasticache memcached failover' error, you can take several steps:
Increase the number of replicas: In a Memcached cluster with multiple replicas, if the primary node fails, one of the replica nodes can take over without causing downtime or data loss. So, if your cluster has only one replica, consider adding more to increase fault tolerance.
Use a different caching engine: If you're experiencing frequent failovers with Memcached, consider switching to a different caching engine like Redis, which uses a different replication mechanism that provides better availability during failovers.
Implement retry logic: When a failover occurs, your application should be designed to retry the request after a certain interval. The application should also be able to handle the case where both the primary and replica nodes fail simultaneously.
Monitor the cluster health: You can set up cloudwatch alarms to monitor the health of your Memcached cluster and get notified when a failover occurs. This will help you take proactive measures to resolve the issue before it affects your application.