After further discussions on IRC, we have concluded the following: In shared mode only the primary owner of a key writes to the shared store, therefore there is no obvious use-case for having a singleton mode which delegates all writes to a single node.
With this in mind, I propose that the singleton option and associated writers be deprecated [1]. If anybody has any objections, please speak up. [1] https://issues.jboss.org/browse/ISPN-6748 Cheers Ryan ----- Original Message ----- From: "William Burns" <mudokon...@gmail.com> To: "infinispan -Dev List" <infinispan-dev@lists.jboss.org> Cc: d...@infinispan.org, remer...@redhat.com Sent: Wednesday, 1 June, 2016 2:54:13 PM Subject: Singleton Cache Stores with Shared Cache Stores Recently there was a start of a discussion regarding singleton cache stores and how they behave. Interestingly according to our documentation [1] and verification code [2] a singleton store cannot be used with a shared cache store. This makes no sense to me as this means you would have a single point of failure for your data. And also as Dan pointed out [3] there is no Singleton cache loader to make sure all the loads are from the coordinator either, which means you could have a read that returns null despite it being in the store/loader. And even looking at [4] it talks about singleton being used so not every node writes to the underlying store, which implies it being shared. I think we have enough proof to update this so a singleton store requires a shared store, but I wanted to make sure we weren't missing something here. Thanks, - Will [1] http://infinispan.org/docs/9.0.x/user_guide/user_guide.html#_configuration_2 [2] https://github.com/infinispan/infinispan/blob/master/core/src/main/java/org/infinispan/configuration/cache/PersistenceConfigurationBuilder.java#L108 [3] https://github.com/infinispan/infinispan/pull/4382#discussion_r65360312 [4] https://github.com/infinispan/infinispan/blob/master/core/src/main/java/org/infinispan/persistence/support/SingletonCacheWriter.java#L40 _______________________________________________ infinispan-dev mailing list infinispan-dev@lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev
