[infinispan-dev] query npe

[Emmanuel Bernard]

Dan worked to understand the problem, here is where we stand without
Sanne's additional knowledge.

The test failing is the following:

    tx1.start();
    cache.remove(key);
    tx1.commit();
    assert queryDeletedKey.getResults().size() == 0;

Surprisingly, the entity is still found in the query and Infinispan
Query returns `null`.

The reason we suspect is the following. While pushing the index changes
is done in sync with the transaction commit (tx sync), the backend is
JGroups and returns right after it has sent the message to the master
node without waiting for the index ack.
This is a good thing as it scales much better but has the nice
side effect of returning incorrect query results right after a change
set is applied (indexing window + index propagation).

My recommendation is to make sure Infinispan Query removes entities
found by the query engine but not present in the grid like we do in
Hibernate Search for the ORM case. Note that this does not solve the
case were you add a new entity and expect to query it *right after the
commit*. There is a similar issue around entity changes. If CapeDwarf
can live with it it will be better off.

An alternative solution would be to create a JGroups backend that waits
for an execution ACK before giving back the had to the client but that
will have scalability problems.

Emmanuel

On Tue 2013-04-09 23:41, Ales Justin wrote:
> Chasing down today's NPE: http://pastie.org/7382216
> 
> I've added this test:
> * https://github.com/capedwarf/capedwarf-blue/commit/d416d5358
> 
> The test fails. ;-)
> 
> deleteAndQueryInA(org.jboss.test.capedwarf.cluster.test.QueryTest): Should not be here: null
> 
> This is the "null" that is the cause of top NPE.
> 
> -Ales
> 

> _______________________________________________
> infinispan-dev mailing list
> infinispan-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/infinispan-dev