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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.
>
> _______________________________________________
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> http://www.linuxvirtualserver.org/
>
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_______________________________________________
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http://www.linuxvirtualserver.org/
LinuxVirtualServer.org mailing list - lvs-users@xxxxxxxxxxxxxxxxxxxxxx
Send requests to lvs-users-request@xxxxxxxxxxxxxxxxxxxxxx
or go to http://lists.graemef.net/mailman/listinfo/lvs-users
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