rohara at redhat
Jan 23, 2012, 8:00 PM
Post #4 of 4
(350 views)
Permalink
|
|
Re: [lvs-users] Cannot figure out failover balancing
[In reply to]
|
|
On 01/23/2012 03:40 PM, Peter Scott wrote:
> Thanks! We're going to look at Pacemaker (which does seem to be
> supported on RHEL6 after all). Looks like what we want.
Pacemaker is not supported in RHEL6. It is considered Tech Preview.
Ryan
> 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 - lvs-users [at] LinuxVirtualServer
>>> Send requests to lvs-users-request [at] LinuxVirtualServer
>>> 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 - lvs-users [at] LinuxVirtualServer
> Send requests to lvs-users-request [at] LinuxVirtualServer
> 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 - lvs-users [at] LinuxVirtualServer
Send requests to lvs-users-request [at] LinuxVirtualServer
or go to http://lists.graemef.net/mailman/listinfo/lvs-users
|
