Re: New thread for : How does Cassandra handle failure during synchronous writes

2011-02-24 Thread Ritesh Tijoriwala
thanks Narendra. I read again the wiki quote you pasted below and now it does make sense. Cassandra's design behavior is to propagate the failed write if it was ever written successfully to atleast one server. I was having hard time trying to work around this but I guess I am starting to think the

Re: New thread for : How does Cassandra handle failure during synchronous writes

2011-02-24 Thread Narendra Sharma
You are missing the point. The coordinator node that is handling the request won't wait for all the nodes to return their copy/digest of data. It just wait for Q (RF/2+1) nodes to return. This is the reason I explained two possible scenarios. Further, on what basis Cassandra will know that the dat

New thread for : How does Cassandra handle failure during synchronous writes

2011-02-24 Thread Anthony John
>>c. Read with CL = QUORUM. If read hits node1 and node2/node3, new data that was written to node1 will be returned. >>In this case - N1 will be identified as a discrepancy and the change will be discarded via read repair >>[Naren] How will Cassandra know this is a discrepancy? Because at Q - on