Hello Honza, 在 2014-07-15二的 15:59 +0200，Jan Friesse写道： > Junliang, > > > Hi all, > > From this mail list , I found some guys had done many latency tests > > with totem protocol. And in corosync configuration file , all parameters > > are set in millisecond's(ms) level. I just wonder if it could be > > It's impossible directly from configuration file. And in a code such > change would be quite difficult. If you want to try, take a look to > qb_loop_timer_add calls (and specially QB_TIME_NS_IN_MSEC constant). > Yes, it is quite difficult to change source code. What I really want to do is finding out how to tune corosync in a small cluster (right now no more than four nodes). > > possible for us to tune corosync in microsecond's(1/1000 ms) level, of > > course, only for two nodes' case(connect two nodes directly without > > switches or routers). Maybe it doesn't make sense to use corosync in > > such "real time" case. > > Honestly, I don't think corosync will work with such a small timeouts. > From time to time it's even problematic to create membership with > default 1sec timeout. Also Linux is not very real time, and (for > example) IO can kill "realtime" behavior. > > Just for curiosity, what are you trying to achieve? Having shorter then > minimal 30 ms for failure detection or something else? > Yeah, a shorter failure detection is my goal. Now we have a two-node cluster, running same application with same inputs, and then produce same output. Finally, we choose an output of one node to use and drop another node's output. It takes about 20ms to do HA switch (just tell which node's output to use) while failures happen. Now, we try to replace this mechanism with corosync and cluster resource manager like pacemaker. Maybe it is a wrong way, but we want to have a try. By the way, what would you do while in such a low switch time situation? Thanks, Junliang Li > Regards, > Honza > > > > > Thanks, > > Junliang Li > > > > _______________________________________________ > > discuss mailing list > > discuss@xxxxxxxxxxxx > > http://lists.corosync.org/mailman/listinfo/discuss > > > _______________________________________________ discuss mailing list discuss@xxxxxxxxxxxx http://lists.corosync.org/mailman/listinfo/discuss
