Memcache vs Java Memory
Simple, probably dumb question: Suppose I have a Java server that stores in memory commonly used keys and values which I can query (let's say in a HashMap)
What's the difference between that and using Memcache (or even Redis)? They both store things in memory. Is there a benefit to one or the other? Does Memcache leaves less of a memory footprint? Can store more in less memory? Faster to query? No difference?
Answer
Advantages of Java memory over memcache:
- Java memory is faster (no network).
- Java memory won't require serialization, you have Java objects available to you.
Advantages of memcache over Java memory:
- It can be accessed by more than one application server, so your cache will be shared among all your app servers.
- It can be accessed by a variety of different servers, so long as they all agree on the key scheme and the serialization.
- It will discard expired cache values, so you get time-based invalidation.