[ https://issues.apache.org/jira/browse/CASSANDRA-2494?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13021242#comment-13021242 ]
Jeremiah Jordan commented on CASSANDRA-2494: -------------------------------------------- I would think that reads at QUORUM should never go backwards. Even if the Write was at ZERO. If there were writes to the cluster of a=1 time=5, a=2 time=10, a=3 time=15, and I do a read at QUORUM which tells me a=3 time=15, I should not be able to do another read at QUORUM and get a=2 time=10. > Quorum reads are not consistent > ------------------------------- > > Key: CASSANDRA-2494 > URL: https://issues.apache.org/jira/browse/CASSANDRA-2494 > Project: Cassandra > Issue Type: Bug > Reporter: Sean Bridges > > As discussed in this thread, > http://www.mail-archive.com/user@cassandra.apache.org/msg12421.html > Quorum reads should be consistent. Assume we have a cluster of 3 nodes > (X,Y,Z) and a replication factor of 3. If a write of N is committed to X, but > not Y and Z, then a read from X should not return N unless the read is > committed to at least two nodes. To ensure this, a read from X should wait > for an ack of the read repair write from either Y or Z before returning. > Are there system tests for cassandra? If so, there should be a test similar > to the original post in the email thread. One thread should write 1,2,3... > at consistency level ONE. Another thread should read at consistency level > QUORUM from a random host, and verify that each read is >= the last read. -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira