(we plan on running similar performance tests on cassandra but wanted to understand the raw foot print first)…..
Someone in ops was doing a test transferring 1T of data from one node to another. I had a huge concern I emailed him that this could end up being a completely sequential write not testing random access speeds. He has twenty 1T drives on each machine and I think he also tried with one 1T drive seeing the same performance which makes sense if writing sequentially. Does anyone know of something that could generate a random access pattern such that we could time that? Right now, he was measuring 253MB / second from the time it took and the 1T of data. I would like to find the much worse case of course. If not, maybe I just generate the same 1,000,000 files on each machine, then randomly delete 1/2 the files and stream them from the other machine as writing those files would all be in random locations again forcing a much worse measurement of MB/sec I would think. Thoughts? Thanks, Dean
