I was using a Amazon Elasticache
cache.t2.medium Redis instance as a cache store for one of the Rails application. Over the time I observed that connections to Redis instance are increasing day by day and once it hit ~1500, the Rails application started throwing connection timeout exceptions:
Error connecting to Redis on redis-host:6379 (Redis::TimeoutError)
On searching over internet, I found that the default parameter group has
timeout value set to 0 which means, any connection that has been initialized to redis will be kept by redis even if the connection initialized by the client is down. Well the first thing I did was to create a new parameter group and set its value to a non-zero integer. However I couldn’t apply the parameter group changes to live production application and hence started looking for alternatives.