[infinispan-dev] DeltaAware: different local/remote behaviour

Hi, I was trying to implement an effective atomic counters [1] in Infinispan using the DeltaAware interface, but trying to use DeltaAware I've spotted an unexpected behaviour; I wanted to have a Delta for getAndIncrement() method, that would simply increment the value without knowing the previous value ahead, and return this previous value. Therefore, I was inserting a fake DeltaAware object into the cache that generates this relative Delta. This works as long as the originator != primary owner, as the delta is generated during marshalling. However, if I store that object locally, the fake object is not used to generate the delta and reapply it on current instance in data container, but it is stored directly. Is such difference in local/remote behaviour bug or feature? (this is the main question in this mail) It seems to me that there are two reasons to use deltas: reducing size of RPCs and reduce their total number. So the design should optimize both. I have another doubts about DeltaAware interface usefulness, tracked in ISPN-5035 [2] - while it reduces bandwith from originator to primary owner, the response from primary owner to originator carries the full value. I also find quite inconvenient that only PutKeyValueCommand somehow works with deltas, but ReplaceCommand does not. I've also noticed that the backup carries the full value [3], not quite a good idea when we're trying to reduce bandwith. Generally, I think that EntryProcessor-like interface would be more useful than DeltaAware. Radim [1] https://github.com/rvansa/infinispan/tree/t_objects [2] https://issues.jboss.org/browse/ISPN-5035 [3] https://issues.jboss.org/browse/ISPN-5037 -- Radim Vansa <rvansa(a)redhat.com&gt; JBoss DataGrid QA