Re: Expanding Cassandra on EC2 with consistency

2012-07-04 Thread Alex Major
Hi Dan, We run RF 2 on RAID0 EBS drives. The reason we use EBS over on-instance storage is two fold; Firstly we have a relatively small cluster ( 4 nodes ), so we're quite sensitive to any AWS issues (at the region level). If we had a larger cluster then we would definitely use ephemeral storage

Re: Expanding Cassandra on EC2 with consistency

2012-07-03 Thread Robin Verlangen
Hi Mike, I'm not sure about all your questions, however you should take a look at LOCAL_QUORUM for your question about consistency level reads/writes. 2012/7/3 Michael Theroux mthero...@yahoo.com Hello, We are currently running a web application utilizing Cassandra on EC2. Given the recent

Re: Expanding Cassandra on EC2 with consistency

2012-07-03 Thread Michael Theroux
Yes, I saw LOCAL_QUORUM. The definition I saw was: Ensure that the write has been written to ReplicationFactor / 2 + 1 nodes, within the local datacenter (requiresNetworkTopologyStrategy) This will allow a quorum within a datacenter. However, I think this means that if availability zones

Re: Expanding Cassandra on EC2 with consistency

2012-07-03 Thread Alex Major
Hi Mike, We've run a small (4 node) cluster in the EU region since September last year. We run across all 3 availability zones in the EU region, with 2 nodes in one AZ and then a further node in each AZ. The latency difference between running inside of and between AZ's has been minimal in our