> We've learned that compaction strategy would be an important point cause > we've ran into 'no space' trouble because of the 'sized tiered' compaction > strategy. If you want to get the most out of the raw disk space LCS is the way to go, remember it uses approximately twice the disk IO.
> From our experience changing any settings/schema during a large cluster is on > line and has been running for some time is really really a pain. Which parts in particular ? Updating the schema or config ? OpsCentre has a rolling restart feature which can be handy when chef / puppet is deploying the config changes. Schema / gossip can take a little to propagate with high number of nodes. On a modern version you should be able to run 2 to 3 TB per node, maybe higher. The biggest concerns are going to be repair (the changes in 2.1 will help) and bootstrapping. I’d recommend testing a smaller cluster, say 12 nodes, with a high load per node 3TB. cheers Aaron ----------------- Aaron Morton New Zealand @aaronmorton Co-Founder & Principal Consultant Apache Cassandra Consulting http://www.thelastpickle.com On 9/05/2014, at 12:09 pm, Yatong Zhang <bluefl...@gmail.com> wrote: > Hi, > > We're going to deploy a large Cassandra cluster in PB level. Our scenario > would be: > > 1. Lots of writes, about 150 writes/second at average, and about 300K size > per write. > 2. Relatively very small reads > 3. Our data will be never updated > 4. But we will delete old data periodically to free space for new data > > We've learned that compaction strategy would be an important point cause > we've ran into 'no space' trouble because of the 'sized tiered' compaction > strategy. > > We've read http://wiki.apache.org/cassandra/LargeDataSetConsiderations and is > this enough or update-to-date? From our experience changing any > settings/schema during a large cluster is on line and has been running for > some time is really really a pain. So we're gathering more info and expecting > some more practical suggestions before we set up the cassandra cluster. > > Thanks and any help is of great appreciation
