Thanks! We're going to look at Pacemaker (which does seem to be supported on RHEL6 after all). Looks like what we want.
On 1/20/2012 5:43 PM, David Coulson wrote: > Why not just setup a resource in rgmanager (I'd say use pacemaker, but > RedHat doesn't support that yet), and move the MySQL IP between the > hosts, rather than messing around with IPVS? > > David > > On 1/20/12 8:13 PM, Peter Scott wrote: >> Hello. We are using the Redhat load balancing add-on that comes on RHEL >> 6. We want to have highly available MySQL; we have two co-master MySQL >> servers that replicate to each other. MySQL says that that updates >> should only come in to one of these at a time because of the possibility >> that conflicting updates arrive at each server simultaneously. So we >> want to use LVS to direct all traffic to one of the co-masters (call it >> mysql01) except when it is down, in which case to direct all traffic to >> the other one (call it mysql02). >> >> We thought this requirement would be common enough to be addressable via >> stock LVS capability. Our initial thought was to set the weight of >> mysql01 to 1 and mysql02 to 0. However, new connections still went to >> mysql02. We discovered >> http://archive.linuxvirtualserver.org/html/lvs-users/2008-10/msg00101.html >> >> and set the /etc/sysctl.conf parameters, also tried setting them via the >> equivalent files in /proc/sys/net/ipv4/vs/, still connections went to >> both servers even when we waited beyond the persistence timeout of 600s. >> >> Because of this behavior, we are not able to test whether our approach >> is sound to begin with; i.e., if mysql01 goes down will traffic be >> redirected to mysql02 even though its weight is 0? We thought that if >> it was the only machine up in its group the weight would not matter. >> But would like to know if that assumption was accurate also. >> >> Here's that section of our lvs.cf: >> >> virtual MySQL { >> active = 1 >> address = 192.168.185.115 eth0:6 >> vip_nmask = 255.255.255.0 >> fwmark = 3306 >> port = 3306 >> persistent = 600 >> use_regex = 0 >> load_monitor = none >> scheduler = wlc >> protocol = tcp >> timeout = 6 >> reentry = 15 >> quiesce_server = 0 >> server MySQL01 { >> address = 192.168.185.51 >> active = 1 >> port = 3306 >> weight = 1 >> } >> server MySQL02 { >> address = 192.168.185.52 >> active = 1 >> port = 3306 >> weight = 0 >> } >> } >> >> Would appreciate any advice. Thanks. >> >> _______________________________________________ >> Please read the documentation before posting - it's available at: >> http://www.linuxvirtualserver.org/ >> >> LinuxVirtualServer.org mailing list - [email protected] >> Send requests to [email protected] >> or go to http://lists.graemef.net/mailman/listinfo/lvs-users _______________________________________________ Please read the documentation before posting - it's available at: http://www.linuxvirtualserver.org/ LinuxVirtualServer.org mailing list - [email protected] Send requests to [email protected] or go to http://lists.graemef.net/mailman/listinfo/lvs-users
