Service Guard cluster with two quorum servers

[Juan de Los Palotes]

Hi Guys.

I have to configurate a Service Guard Cluster with 6 nodes, I think to use two quorum servers in order to have some redundance in this area. Is this possible on MC/Service Guard??

Thanks in Advance.
JDP

[melvyn burnard]

Not currently. You could create the QS as a package on another SG cluster, or set up an alternate QS that could be fired up manualy in the event of a crisis

[freddy_21]

Hi JDP,

function from Quorum server is avoid split brain.

if your node up less or equal 50% ( in your case 3 servers down), your cluster will be panic. But if you have quorum server, your cluster will not panic.

Quorum server not in a member of cluster. you must have other server.

Regards
Freddy

[Wim Rombauts]

Where will these 6 servers physically be ?

In 1 data center ? The just make sure they are connected to at least 3 different power circuits so that a limited power failure only affects 2 servers maximum.
If the complete data center goes down, no server will be left and there is no need for a quorum server.

In 2 datacenters ? Then you can use a Quorum Server, but it will only function as designed when this QS is placed at a third, independent location, and the only moment that this QS will be needed is when 1 datacenter goes down suddenly, or communication between the datacenters is cut. At that time, the servers in the datacenter that can access the QS will survive. When servers go down one by one, the quorum server has nu purpose untill you shut don the fifth server and only 1 remains. You probably won't go that far.

In 3 datacenters : A quorum server is next to useless as there is no single point of failure that can bring half your cluster down. Only when 2 datacenters go down, a quorum server in a 4th location could be of any help.

[Emil Velez]

There can be only one..

You do not need a quorum server for a 6 node cluster.


if there is no way that you will loose 3 nodes at one time then do not configure it.