[infinispan-dev] rehashing hazard

[Manik Surtani]

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/java/org/infinispan/distribution/InvertedLeaveTask.java?r=2351#l83

Or is this not the case anymore, since Vladimir inverted the LeaveTask?  Vladimir, can you confirm that these 2 actions (providing state and flushing/tx logs) happen in the same thread?

> The easy way to achieve this is  to only do push, i.e. A sends the state and then drains tx log.
> This can be reproduce by running ConcurrentNonOverlappingLeaveTest.testTransactional (fails aprox 1/5)
> 
> Cheers,
> Mircea
> 
> 
> _______________________________________________
> infinispan-dev mailing list
> infinispan-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/infinispan-dev

--
Manik Surtani
manik at jboss.org
Lead, Infinispan
Lead, JBoss Cache
http://www.infinispan.org
http://www.jbosscache.org