As a test, adding a 7th node in the first AZ will stream from both the two existing nodes in the same AZ.
Aggregate streaming bandwidth at the 7th node is approximately 12 MB/sec when all limits are set at 800 MB/sec, or about double what I saw streaming from a single node. This would seem to indicate that the sending node is limiting our streaming rate. Mike On Tue, Jul 2, 2013 at 3:00 PM, Mike Heffner <m...@librato.com> wrote: > Sankalp, > > Parallel sstableloader streaming would definitely be valuable. > > However, this ring is currently using vnodes and I was surprised to see > that a bootstrapping node only streamed from one node in the ring. My > understanding was that a bootstrapping node would stream from multiple > nodes in the ring. > > We started with a 3 node/3 AZ, RF=3 ring. We then increased that to 6 > nodes, adding one per AZ. The 4th, 5th and 6th nodes only streamed from the > node in their own AZ/rack which led to the serial sstable streaming. Is > this the correct behavior for the snitch? Is there an option to stream from > multiple replicas across the az/rack configuration? > > Mike > > > On Tue, Jul 2, 2013 at 1:53 PM, sankalp kohli <kohlisank...@gmail.com>wrote: > >> This was a problem pre vnodes. I had several JIRA for that but some of >> them were voted down saying the performance will improve with vnodes. >> The main problem is that it streams one sstable at a time and not in >> parallel. >> >> Jira 4784 can speed up the bootstrap performance. You can also do a zero >> copy and not touch the caches of the nodes which are contributing in the >> build. >> >> >> https://issues.apache.org/jira/browse/CASSANDRA-4663 >> https://issues.apache.org/jira/browse/CASSANDRA-4784 >> >> >> On Tue, Jul 2, 2013 at 7:35 AM, Mike Heffner <m...@librato.com> wrote: >> >>> >>> On Mon, Jul 1, 2013 at 10:06 PM, Mike Heffner <m...@librato.com> wrote: >>> >>>> >>>> The only changes we've made to the config (aside from dirs/hosts) are: >>>> >>> >>> Forgot to include we've changed this as well: >>> >>> -partitioner: org.apache.cassandra.dht.Murmur3Partitioner >>> +partitioner: org.apache.cassandra.dht.RandomPartitioner >>> >>> >>> Cheers, >>> >>> Mike >>> -- >>> >>> Mike Heffner <m...@librato.com> >>> Librato, Inc. >>> >>> >> > > > -- > > Mike Heffner <m...@librato.com> > Librato, Inc. > > -- Mike Heffner <m...@librato.com> Librato, Inc.
