hello, we are quite inexperienced with cassandra at the moment and are playing around with a new cluster we built up for getting familiar with cassandra and its possibilites.
while getting familiar with that topic we recognized that repairs in our cluster take a long time. To get an idea of our current setup here are some numbers: our cluster currently consists of 4 nodes (replication factor 3). these nodes are all on dedicated physical hardware in our own datacenter. all of the nodes have 32 cores @2,9Ghz 64 GB ram 2 ssds (raid0) 900 GB each for data 1 seperate hdd for OS + commitlogs current dataset: approx 530 GB per node 21 tables (biggest one has more than 200 GB / node) i already tried setting compactionthroughput + streamingthroughput to unlimited for testing purposes ... but that did not change anything. when checking system resources i cannot see any bottleneck (cpus are pretty idle and we have no iowaits). when issuing a repair via nodetool repair -local on a node the repair takes longer than a day. is this normal or could we normally expect a faster repair? i also recognized that initalizing of new nodes in the datacenter was really slow (approx 50 mbit/s). also here i expected a much better performance - could those 2 problems be somehow related? br// roland
