Is there any guidance table for window_size and max_messages with different node configuration. Or do I have to experiment each time to get the correct values.
On Mon, Jan 2, 2017 at 5:35 PM, Jan Friesse <[email protected]> wrote: > Hello, >> >> I have a four node cluster. Each node connected with a centralized switch. >> MTU size is default, 1500. On each node, a program continuously tries to >> multi-cast as many messages as possible. With the default settings >> (corosync.conf), buffer overflow does *not* occur till program runs on >> three nodes. However as soon as fourth node start multi-casting, overflow >> occur and significantly reduce the performance. >> >> Why buffer overflow with just four nodes? >> >> Is hardware topology, centralized switch, is not correct? >> > > Centralized switch is ok. > > >> Later, I reduced window_size and max_messages to 20 and 5 respectively. No >> overflow but not sure whether performance is as expected. >> >> I would like to better understand these two parameters. Lets say in a >> cluster of four nodes, I have window_size 50 and max_messages also set to >> 50. Does that mean only one node will be able to multi-cast in a single >> token rotation? If one node was not able to multi-cast because window_size >> > > Not exactly. Token contains "backlog" field which is updated by all > members. This backlog is then used to find out if there is not a member who > wasn't able to send messages (whose backlog is too big). So let's say one > node sent a lot messages in one round, and second node sent no messages. In > next round, first node finds out this information and its number of allowed > messages to sent is lowered (or in extreme case goes > to zero) so second node can send some messages. > > Regards, > Honza > > is reached, when and how this node will get opportunity to send message? >> >> Thanks, >> Satish >> >> >> >> _______________________________________________ >> Users mailing list: [email protected] >> http://lists.clusterlabs.org/mailman/listinfo/users >> >> Project Home: http://www.clusterlabs.org >> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf >> Bugs: http://bugs.clusterlabs.org >> >> > > _______________________________________________ > Users mailing list: [email protected] > http://lists.clusterlabs.org/mailman/listinfo/users > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org >
_______________________________________________ Users mailing list: [email protected] http://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
