How partitioning works in Hazelcast?

Question

From what I have seen the applications of Hazelcast are most commonly found in architectures with more than 50 nodes. Does it makes sense to use Hazelcast on a 1 up to a 4 node architecture? If yes what is the best strategy that I should follow regarding the partitions and the hazelcast instances.

Let's say that I am using Hazelcast on only one node! How many hazelcast instances should I use? and should I let the partitions default number as it is (271) ,or if it is better to change it what are the factors that I need to consider for taking my decision.

Please someone enlighten me on this one.

Answer 1

It depends your needs :)

What hazelcast does for e.g. a map is the calculate the hash of a key, do a mod partition count on it and that determines the partition the key will be stored on.

For a single node setup Hazelcast could make sense because the map provides more than a regular map, but its true value is with a multinode (2 or more).

We have customers that run with smaller clusters e.g. 5/6 nodes. Even with 2 nodes you still get certain features.

About the partition count: we aim that the partition size should be max 50/100 mb. So with 271 partitions you get +/13 gigs of data (50mb). If you would have 26 gigs of data, double the number of partitions.