But it shouldn’t matter. I have missing data, and no errors, which shouldn’t be possible except with CL=ANY.
FWIW, I’m working on some sample code so I can post a Jira. Robert On Aug 21, 2015, at 5:04 AM, Robert Wille <rwi...@fold3.com<mailto:rwi...@fold3.com>> wrote: RF=1 with QUORUM consistency. I know QUORUM is weird with RF=1, but it should be the same as ONE. If’s QUORUM instead of ONE because production has RF=3, and I was running this against my test cluster with RF=1. On Aug 20, 2015, at 7:28 PM, Jason <jkushm...@rocketfuelinc.com<mailto:jkushm...@rocketfuelinc.com>> wrote: What consistency level were the writes? ________________________________ From: Robert Wille<mailto:rwi...@fold3.com> Sent: 8/20/2015 18:25 To: user@cassandra.apache.org<mailto:user@cassandra.apache.org> Subject: Written data is lost and no exception thrown back to the client I wrote a data migration application which I was testing, and I pushed it too hard and the FlushWriter thread pool blocked, and I ended up with dropped mutation messages. I compared the source data against what is in my cluster, and as expected I have missing records. The strange thing is that my application didn’t error out. I’ve been doing some forensics, and there’s a lot about this that makes no sense and makes me feel very uneasy. I use a lot of asynchronous queries, and I thought it was possible that I had bad error handling, so I checked for errors in other, independent ways. I have a retry policy that on the first failure logs the error and then requests a retry. On the second failure it logs the error and then rethrows. A few retryable errors appeared in my logs, but no fatal errors. In theory, I should have a fatal error in my logs for any error that gets reported back to the client. I wrap my Session object, and all queries go through this wrapper. This wrapper logs all query errors. Synchronous queries are wrapped in a try/catch which logs and rethrows. Asynchronous queries use a FutureCallback to log any onFailure invocations. My logs indicate that no errors whatsoever were reported back to me. I do not understand how I can get dropped mutation messages and not know about it. I am running 2.0.16 with datastax Java driver 2.0.8. Three node cluster with RF=1. If someone could help me understand how this can occur, I would greatly appreciate it. A database that errors out is one thing. A database that errors out and makes you think everything was fine is quite another. Thanks Robert
