database design

Hi all, Just some thoughts and question I have about cassandra data modeling. If I understand well, cassandra is better on writing than on reading. So you have to think about your queries to design cassandra schema. We are doing incremental design, and already have our system in production and we

Renaming keyspace

Hi all, We are running .6.12, is there any particular precaution to rename the keyspace, is it enough to shutdown cassandra, update storag-conf.xml, rename data directory and start cassandra again. Thanks for your help. Jean-Yves

Re: Calculate memory used for keycache

One additionnal question, I don't really understand what is in the key cache. I have a column family with only one key, and the keycache size is 118 ... ? Any idea. Thks. Jean-Yves

Re: Out of Memory every 2 weeks

Thank you, I am going to try that.

Out of Memory every 2 weeks

Sorry to create a new thread about Out of Memory problem, but I checked all other threads and did not find the answer. We have a running cluster of 2 cassandra nodes replication factor = 2 on red hat 4.8 32 bits with 4 G of memory where we run periodicaly out of memory (every 2 weeks) and both n

Re: cassandra 0.6.11 binary package problem

On Thu, Feb 3, 2011 at 6:06 AM, Jean-Yves LEBLEU wrote: >> Hi all, >> >> Just for info, in apache-cassandra-0.6.11-bin.tar.gz there are both >> apache-cassandra-0.6.10.jar  and apache-cassandra-0.6.11.jar in the >> lib directory. >> >> Causing troubles to

cassandra 0.6.11 binary package problem

Hi all, Just for info, in apache-cassandra-0.6.11-bin.tar.gz there are both apache-cassandra-0.6.10.jar and apache-cassandra-0.6.11.jar in the lib directory. Causing troubles to my upgrade scripts which use this file to get installed version and check if upgrade needed . :( Thanks for the g

Re: Do you have a site in production environment with Cassandra? What client do you use?

Java + Pelops Cassandra 0.6.8

Re: Data management on a ring

though. > Adding all 8 at once is probably a bad idea. > > How about you make a new cluster of 8 nodes, manually assign tokens and > then copy the data from the 2 node ring to the 8 node. Then move the 2 > original nodes into the new cluster? > > Hope that helps. > Aaron &g

Data management on a ring

Hello all, We have an installation of 10 nodes, and we choose to deploy 5 rings of 2 nodes. We would like to change to a ring of 10 nodes. Some data have to be replicated on the 10 nodes, some should stay on 2 nodes. Do you have any idea or documentation pointer in order to have a ring of 10 nod

Re: Changing column families and drain

am assuming you are on 0.6*. > Hope that helps > Aaron > > > On 13 Oct 2010, at 21:00, Jean-Yves LEBLEU wrote: > > Hi all, > > When I look at the wiki the procedure to change the column family is : > > >1. Empty the commitlog with "nodetool drain." &g

Changing column families and drain

Hi all, When I look at the wiki the procedure to change the column family is : 1. Empty the commitlog with "nodetool drain." 2. Shutdown Cassandra and verify that there is no remaining data in the commitlog. 3. Delete the sstable files (-Data.db, -Index.db, and -Filter.db) for any

Re: Server takes a long time to answer

s a lot like it's running out of memory.  Check your logs for > GCInspector lines. > > Easiest solution: increase the argument to Xmx in cassandra.in.sh. > > On Mon, Aug 2, 2010 at 8:05 AM, Jean-Yves LEBLEU wrote: >> Hi all, >> >> We have a cassandra installat

Server takes a long time to answer

Hi all, We have a cassandra installation with two nodes in a ring, replication factor = 2, some times cassandra becomes non-responsive, it takes about three minutes before answering to a get. Do you have any idea of what we should check when it happens ? Or what could cause the problem. We are usi