http://www.datastax.com/support-forums/topic/quorum-write-failing-partially-and-no-rollback Software, Support, and Training for Apache Cassandra en-US Sun, 19 May 2013 06:04:39 +0000 http://bbpress.org/?v=1.0.3 q http://www.datastax.com/support-forums/search.php http://www.datastax.com/support-forums/topic/quorum-write-failing-partially-and-no-rollback#post-1427 Thu, 22 Mar 2012 21:16:45 +0000 Anonymous 1427@http://www.datastax.com/support-forums/ <p>That is correct. In addition, hinted handoff (<a href="http://www.datastax.com/dev/blog/understanding-hinted-handoff" rel="nofollow">http://www.datastax.com/dev/blog/understanding-hinted-handoff</a>) can also propagate the mutation to the node that failed to receive the write in the first place. </p> <p>Cassandra has no distributed transactions, and hence no distributed rollback. The error returned to the client only indicates that the contract/requirement (consistency level) that the client specified could not be fulfilled. That error doesn't make any claims about the actual state of the data from that write in the cluster.</p> <p>Best practices in that situation would be to do any of<br /> 1) Have your client retry the write<br /> 2) Have your client retry the write with a lower consistency level<br /> 3) Have your client send a delete operation to overwrite that previous mutation (assuming that the columns you are writing are new columns and can be safely deleted).</p> <p>-Tupshin </p> http://www.datastax.com/support-forums/topic/quorum-write-failing-partially-and-no-rollback#post-1426 Thu, 22 Mar 2012 20:55:18 +0000 Anonymous 1426@http://www.datastax.com/support-forums/ <p>Hello,</p> <p>Something in the doc is puzzling me ( <a href="http://www.datastax.com/docs/1.0/dml/about_writes" rel="nofollow">http://www.datastax.com/docs/1.0/dml/about_writes</a> ) :</p> <p>"For example, if using a write consistency level of QUORUM with a replication factor of 3, Cassandra will send the write to 2 replicas. If the write fails on one of the replicas but succeeds on the other, Cassandra will report a write failure to the client. However, the write is not automatically rolled back on the other replica."</p> <p>If it is not rolled back, does it means that upon a read repair or a node repair this data will be copied to other replicas ?</p> <p>Thanks in advance<br /> Nicolas. </p>