Re: [infinispan-dev] rehashing hazard

On 22 Oct 2010, at 12:07, Manik Surtani wrote: > > On 21 Oct 2010, at 22:54, Mircea Markus wrote: > >> Hi, >> >> ISPN-180 requires some significant code changes around re-hashing, so I've decided to make the rehashing-related test suite more stable before changing the code. >> I've fixed some, but transactional rehash tests are still failing. Here is why: >> >> {A,B,C, D}, num owners= 2. A's state is {(k,v)} and a transactions is prepared with {(k, otherValue)} on A. >> B crashes. >> two things happen with A's state: >> 1. on C an thread pulls state from A >> 2. A sends transaction state to C on another thread >> >> Whit the right timing: >> - 2 executes first (tx log is drained) >> - tx commits - this applies the changes on C as well >> - 1 executes last >> Data ends up inconsistent: >> A's states is {(k, otherValue)} while C's state is {(k,v)} >> >> State transfer and tx log needs to be sequential (not parallel). > > But it is sequential. > > http://fisheye.jboss.org/browse/Infinispan/branches/4.2.x/core/src/main/j... no :) The operations that need to be sequential are state transfer and tx log transfer. State is being *pulled* by C (thread running on C) and tx log is *pushed* by A (thread running on A). Two threads running in different VMs.