Increasing the number of threads alone won't help, because you need to add connectionsPerHost-awareness to StreamPlan.requestRanges (otherwise only a single connection per host is created) similar to what was done to StreamPlan.transferFiles by CASSANDRA-3668, but maybe bit trickier. There's an open ticket to support that on CASSANDRA-4663
There's also another discussion on improving rebuild parallelism on CASSANDRA-12015. 2016-06-16 14:43 GMT-03:00 Anubhav Kale <anubhav.k...@microsoft.com>: > Hello, > > > > I noticed that StreamCoordinator.ConnectionsPerHost is always set to 1 > (Cassandra 2.1.13). If I am reading the code correctly, this means there > will always be just one socket (well, 2 technically for each direction) > between nodes when rebuilding thus the data will always be serialized. > > > > Have folks experimented with increasing this ? It appears that some > parallelism here might help rebuilds in a significant way assuming we > aren’t hitting bandwidth caps (it’s a pain for us at the moment to rebuild > nodes holding 500GB). > > > > I’m going to try to patch our cluster with a change to test this out, but > wanted to hear from experts as well. > > > > Thanks ! >
