We want to switch from memcachedb to redis. As the site has very high usage and the caching is kind of critical, we wanted to see if it is possible to make a test-deploy with both memcachedb and redis running. Only once we confirmed that all keys are created correctly (and the data matches) we want to kill of the memcachedb and fully switch to redis.
so basicly the key should be set on both memcachedb and redis, but get operations should only get from memcachedb until we switch over. does anybody has experience with some scenario like that and can suggest a possible configuration?
Yes this is an admirable step switching to redis rather than memcached.
It is not just because redis is newer and its development is catching up very fast but because of the features that it offers.Redis has many advantageous features like replication, persistence storage and sentinel for auto-failover & moreover extensive commands set it provides.This is why most users prefer using it over Memcached which is just a key value cache.
In my experience I have seen few use cases when, Redis is typically used for solving complex problems using its extensive commands set, e.g. UNION and INTERSECT between sets/sorted-set, and Memcached is used for storing raw data in a scaling manner.
For your test running purposes you can try the similar configuration.
It will always be my pleasure to clarify your concern till the best I can.
Please comment for more explanations in case you need.
cheers :-)