Re: [infinispan-dev] Write skew check implementation

Hi, I am progressing with my implementation of total-order-based commit protocol for the partial replication mode, and I would be grateful if you could help me understanding how the write skew check is implemented in ISPN. Assume the scenario in which a node, say n1, that owns a data item d receives a prepare message for a transaction, say T, originated on different replica n2. Of course write skew check is enabled. After n1 acquiring the lock on d, it should check whether the value of d read during T's execution is still the most recently committed one. I may be missing something here, but looking at [1] (lines 160 to 168) and [2] at copyForUpdate method, n1 is reading twice the value of d that is locally stored (once in line 160([1]) to create the RepeatableReadEntry and a second time in line 52([2]) to do the write skew check). I would have expected that the node that originated the transaction would send the values that it read (before writing them) in piggyback with the prepare message, in order to allow the "owners" to perform the write skew. Thanks Pedro [1] https://github.com/infinispan/infinispan/blob/master/core/src/main/java/o... [2] https://github.com/infinispan/infinispan/blob/master/core/src/main/java/o... -- INESC-ID Lisboa, sala 511 gsd.inesc-id.pt/~pruivo _______________________________________________ infinispan-dev mailing list infinispan-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev