Done: https://issues.apache.org/jira/browse/CASSANDRA-2490
-Jeffrey
-Original Message-
From: Jonathan Ellis [mailto:jbel...@gmail.com]
Sent: Friday, April 15, 2011 7:39 PM
To: user@cassandra.apache.org
Cc: Jeffrey Wang
Subject: Re: DatabaseDescriptor.defsVersion
I think you found a bug; it should be volatile. (Cassandra does
already make sure that only one change runs internally at a time.)
Can you create a ticket?
On Fri, Apr 15, 2011 at 6:04 PM, Jeffrey Wang jw...@palantir.com wrote:
Hey all,
I've been seeing a very rare issue with schema change conflicts on 0.7.3 (I
am serializing all schema changes to a single Cassandra node and waiting for
them to finish before continuing). Occasionally a node in the cluster will
never report the correct schema, and I think it may have to do with
synchronization on DatabaseDescriptor.defsVersion.
As far as I can tell, it is a static variable accessed by multiple threads
but is not protected by synchronized/volatile. I was able to write a test in
which one thread never reads the modification done by another thread (as is
expected by an unsynchronized variable). Should this be fixed or is there a
higher level reason this does not need to be synchronized (in which case I
should continue looking for the reason why my schemas don't agree)? Thanks.
-Jeffrey
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com
