Correct, replication factor of 1. I've been reading and researching as fast as possible so I'm also starting to realize what some of the configurations actually mean and getting a clearer picture. My request to the Cassandra community was a desperate, "Oh man! I F'd up!" moment, and didn't have the time to Google it myself :-)
-----Original Message----- From: Jonathan Ellis [mailto:jbel...@gmail.com] Sent: Thursday, March 24, 2011 9:49 PM To: user@cassandra.apache.org Cc: Jared Laprise; aaron morton Subject: Re: URGENT HELP PLEASE! Each row is replicated to replication_factor nodes, not the entire cluster (or you couldn't scale writes by adding machines). Sounds like you're running with RF=1. On Thu, Mar 24, 2011 at 10:44 PM, Jared Laprise <ja...@webonyx.com> wrote: > Thanks for the responses. I got everything working again, and have some ideas > on why but am not completely sure. > > How I got it working again was simply bring the second node back online. I > was under the assumption that all data is replicated between nodes > (eventually). Am I incorrect? It would seem that each node stores different > data and delegates the read request to whichever node holds the data. > Although I've spent a lot of time with Cassandra in a single node environment > I think I may be lacking a bit of understanding on how Cassandra behaves in a > clustered environment. > > > -----Original Message----- > From: Jonathan Ellis [mailto:jbel...@gmail.com] > Sent: Thursday, March 24, 2011 8:22 PM > To: user@cassandra.apache.org > Cc: aaron morton > Subject: Re: URGENT HELP PLEASE! > > Right, Cassandra doesn't keep old versions around so to see an old version > you have to have uncompacted data and whack the new data -- either by blowing > away sstables or not replaying the commitlog. > > Snapshots flush before creating their hard links, which rules out any > commitlog problems. > > If you ran out of disk space you wouldn't get past the commitlog append, so > you'd never get new data in at all after that. > > Sounds like an environmental problem, not Cassandra specific. > > On Thu, Mar 24, 2011 at 9:10 PM, aaron morton <aa...@thelastpickle.com> wrote: >> Was there anything in the server logs during startup ? >> I've not heard of this happening before and it's hard think of how / >> why cassandra could revert it's data. Other than something external >> playing with the files on disk Aaron On 25 Mar 2011, at 13:49, Jared >> Laprise wrote: >> >> Hello all, I'm running 2 Cassandra 6.5 nodes and I brought down the >> secondary node and restarted the primary node. After Cassandra came >> back up all data has been reverted to several months ago. >> >> I could really use some incite here, this is a production website and >> I need to act quickly. I have a cron job that takes a snapshot every >> night, but even with that I tried to restore a snapshot on my local >> development environment and it was also missing a ton of data. >> >> Any help will be so appreciated. >> >> >> > > > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder of DataStax, the source for professional Cassandra support > http://www.datastax.com > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com
