[infinispan-dev] Doubts about TxDistributionInterceptor and possible break in transaction isolation

[Mircea Markus]

On 17 Jun 2013, at 16:11, Dan Berindei <dan.berindei at gmail.com> wrote:

> > I think that, given that the local node is not owner, the lock acquisition is redundant even for pessimistic caches.
> > Mind creating a test to check if dropping that lock acquisition doesn't break things?
> 
> I created a JIRA with low priority since it does not affect the
> transaction outcome/isolation and I believe the performance impact
> should be lower (you can increase the priority if you want).
> 
> https://issues.jboss.org/browse/ISPN-3237
> 
> If we don't lock the L1 entry, I think something like this could happen:

There is a lock happening *without* L1 enabled.

> 
> tx1 at A: remote get(k1) from B - stores k1=v1 in invocation context
> tx2 at A: write(k1, v2)
> tx2 at A: commit - writes k1=v2 in L1
> tx1 at A: commit - overwrites k1=v1 in L1
> 
> 

Cheers,
-- 
Mircea Markus
Infinispan lead (www.infinispan.org)