ServiceGuard - Number of Nodes in Cluster

[Kevin Liquori_1]

I'm new to ServiceGuard and I'm working on the design of a cluster for our datacenter. For this initial exercise I need to configure failover for servers within a single datacenter. Consider this scenario:

node1 fails to node2
node3 fails to node4

In such a situation is it better to put all four nodes into a single cluster or create two clusters since the node pairs are independent? Are there management complexity issues after reaching a certain number of nodes in a cluster? I'll end up with approximately 12 nodes.

Thanks is advance.
Kevin

[Uday_S_Ankolekar · Accepted solution]

You can design two node cluster or may be four node cluster, active/active or active /passive.
All depends on capacity of your servers. In the event of failover can your server mange to take the load of application/database from other node(s)?
Two node clusters are easy to manage.

-USA..

[Masud Parvez]

Based upon your application requirement you have to choose 2 node or 4 node cluster.

2 node cluster is easy to manage. But if you are looking for more redundancy and load balance then you can choose 4 node.

It is all about package (application) which you need to run on your node. When you are looking for package failover your hardware have to capable to handle this.

[Deepak Kr]

Hi Kevin,

You can choose either choose manageability or high availablilty criteria.

For a 2 nodes cluster confguration and management is easy but flip side is you will have less number of failover nodes in case some thing goes wrong with package.

Same this is advantage in case of 4 Nodes clsuter but management tasks are little more as compared to 2 nodes SG Cluster.

So you can decide depending upon the application/database you will run in this setup.

You can refer to following helpful links:

http://www.pearsonhighered.com/samplechapter/0131463969.pdf
http://www.eventoshp.com/SolucionesHP/Documentos/Serviceguard.pdf
Answer to your second question is: Yes

12 nodes will work in SG Cluster.

[Kevin Liquori_1]

I appreciate everyones advice. Administration versus Redundancy makes sense to me in planning my approach. I wanted to verify theres more than one way to do it.

Thanks,
Kevin

[Deepak Kr]

Hi Kevin,

I would suggest to do planning based on application manageability after all it is the application that needs to made highly available.

Making large node cluster will increase your administrative work but same time you will have higher level of redundancy.

Regds.
Deepak