Re: Memory overhead of vector clocks…. how often are they pruned?

2011-08-27 Thread Kevin Burton
Yeah… I gathered that this was a memory for availability tradeoff… I was just curious how much memory was involved. It seems a shame to waste so much memory and I can't help shake the feeling that a lot of this is unnecessary. In some situations I could see Cassandra using up to 4x more memory th

Talking at Stack Overflow Dev Days - Sydney

2011-08-27 Thread aaron morton
Hi folks, I'm talking about Cassandra at the first ever Stack Overflow Dev Days conference in Sydney on October 26 http://devdays.stackoverflow.com/sydney/ . I've only got 45 minutes but I'm going to storm through as much as I can about how things work at the cluster level and the read

Re: mmap segment underflow

2011-08-27 Thread Jonathan Ellis
My guess would be CASSANDRA-2675. Upgrade to the latest version in your release series, if you haven't. On Sat, Aug 27, 2011 at 9:53 AM, Chad Johnson wrote: > Hi, > > We periodically get the following exception in our Cassandra cluster. What I > mean by periodically is once or twice a week. It

Re: Repairing lost data

2011-08-27 Thread Anthony Molinaro
I'm pretty sure that was a bug fixed in a later 0.6.x release so you might be able to upgrade and the exceptions might go away. We run 0.6.13 with a minor mod to support data expiration and will probably do so indefinitely since there no way to upgrade without shutting our site down :( -Anthon

mmap segment underflow

2011-08-27 Thread Chad Johnson
Hi, We periodically get the following exception in our Cassandra cluster. What I mean by periodically is once or twice a week. It always affects the same column family ( containing super columns). The frequency of the problems seems to center on the same couple nodes, but not always. I've been

Re: Repairing lost data

2011-08-27 Thread Peter Schuller
> Is it possible to use nodetool repair to fix this with the current data set? > > I issued a repair command and the other nodes seem to be doing the > correct things but I concerned  by this: "Uncaught exception in thread > Thread[ROW-READ-STAGE:4327,5,main]" > > Will the affect node ever be able

Repairing lost data

2011-08-27 Thread Jake Maizel
Hello, In a cluster running 0.6.6 one node lost part of a data file due to an operator error. An older file was moved in place to bring cassandra up again. Now we get lots of these in the log: 2011-08-27_10:30:55.26219 'ERROR [ROW-READ-STAGE:4327] 10:30:55,258 CassandraDaemon.java:87 Uncaught