I have 72 nodes in the cluster, across 8 datacenters.. the moment I try to increase the node above 84 or so, the issue starts.
I am still using CMS Heap, assuming it will create more harm if I increase the heap size beyond 8G(recommended). On Wed, Aug 29, 2018 at 6:53 PM Jeff Jirsa <jji...@gmail.com> wrote: > Given the size of your schema, you’re probably getting flooded with a > bunch of huge schema mutations as it hops into gossip and tries to pull the > schema from every host it sees. You say 8 DCs but you don’t say how many > nodes - I’m guessing it’s a lot? > > This is something that’s incrementally better in 3.0, but a real proper > fix has been talked about a few times - > https://issues.apache.org/jira/browse/CASSANDRA-11748 and > https://issues.apache.org/jira/browse/CASSANDRA-13569 for example > > In the short term, you may be able to work around this by increasing your > heap size. If that doesn’t work, there’s an ugly ugly hack that’ll work on > 2.1: limiting the number of schema blobs you can get at a time - in this > case, that means firewall off all but a few nodes in your cluster for 10-30 > seconds, make sure it gets the schema (watch the logs or file system for > the tables to be created), then remove the firewall so it can start the > bootstrap process (it needs the schema to setup the streaming plan, and it > needs all the hosts up in gossip to stream successfully, so this is an ugly > hack to give you time to get the schema and then heal the cluster so it can > bootstrap). > > Yea that’s awful. Hopefully either of the two above JIRAs lands to make > this less awful. > > > > -- > Jeff Jirsa > > > On Aug 29, 2018, at 6:29 PM, Jai Bheemsen Rao Dhanwada < > jaibheem...@gmail.com> wrote: > > It fails before bootstrap > > streaming throughpu on the nodes is set to 400Mb/ps > > On Wednesday, August 29, 2018, Jeff Jirsa <jji...@gmail.com> wrote: > >> Is the bootstrap plan succeeding (does streaming start or does it crash >> before it logs messages about streaming starting)? >> >> Have you capped the stream throughput on the existing hosts? >> >> -- >> Jeff Jirsa >> >> >> On Aug 29, 2018, at 5:02 PM, Jai Bheemsen Rao Dhanwada < >> jaibheem...@gmail.com> wrote: >> >> Hello All, >> >> We are seeing some issue when we add more nodes to the cluster, where new >> node bootstrap is not able to stream the entire metadata and fails to >> bootstrap. Finally the process dies with OOM (java.lang.OutOfMemoryError: >> Java heap space) >> >> But if I remove few nodes from the cluster we don't see this issue. >> >> Cassandra Version: 2.1.16 >> # of KS and CF : 100, 3000 (approx) >> # of DC: 8 >> # of Vnodes per node: 256 >> >> Not sure what is causing this behavior, has any one come across this >> scenario? >> thanks in advance. >> >>
