Consistent copies of replicated cache?

[dnielben]

Hi,

How does jbosscache guarantees consistency of replicas?

Example: If I have one cache C1 on host H1 and I execute:

C1.put("/a/b", "Key1", "1");
C1.put("/a/b", "Key1", "2");

All the replicatec caches are going to see the two events in the same order or it could happen that some replicated caches will see the events in a different order and then I will have inconsistent replicated caches?

Do I have to change the stack of protocols in to have such guarantee? for example using a total order of events?

Thanks,
Daniel

[manik]

Depends on how you configure and use your cache. E.g., if you use synchronous replication or wrap the calls in a transaction (or both) you'd pretty much guarantee that the other instances see it in the same order.

[dnielben]

So, but in the case of synchronous communication if my two instructions arrive from different hosts Ex:

Host1:
C1.put("/a/b", "Key1", "1");

Host2:
C1.put("/a/b", "Key1", "2");

Can we guarantee that we are going to receive booth messages in the same order in all hosts?

Thanks,
Daniel

[manik]

If they are from different hosts, then no. We don't acquire a cluster-wide lock when you invoke the call.