Tuesday, November 12, 2013

SCOM 2012 Management Servers: Better One Or Two Too Many…

When the dino’s ruled the world
Back in the old days of SCOM 2007x one really had to consider how many SCOM 2007x Management Servers to roll out, mostly based on these two facts:
  1. Every single SCOM 2007x Management Server required a special SCOM license;
  2. Many environments were using physical hardware for their servers.

So any additional SCOM 2007x Management Server was an extra burden to the (many times already loaded) IT budgets. On top of these costs one had to consider the extra costs of the Server OS license as well.

In situations like these many times the minimum amount of required SCOM 2007x Management Servers was rolled out, never the optimum amount, resulting in an underperforming SCOM 2007x Management Group.

Back to the current situation
With the roll out of the System Center 2012 Product, Microsoft revamped the license model accordingly. This resulted in the related System Center 2012 Management Servers becoming free of System Center 2012 licenses since only the managed end points require a SC 2012 license.

So in the case of the SCOM 2012 Management Servers, these servers became free of the SC 2012 license (of course, when these servers are ‘touched’ by Orchestrator for instance, these servers do require a SC 2012 license…).

On top of it, virtualization of workloads had become default as well. So instead of rolling out physical hardware for servers, VMs were spawned as required. And when the underlying virtualization hosts are covered by a Data Center license for the Windows Server OS, the VMs running on top of those same virtualization hosts are covered as well by a Windows Server OS license. So no hidden costs!

Good to know, the SC 2012 license comes in two flavors: Standard and Data Center. Only difference is virtualization density. All components found in the System Center 2012 Product are covered by both licenses. Many times the SC 2012 Data Center license is the best solution since many virtualization hosts do run many VMs.

And now a second nice thing kicks in: with the Data Center flavor of the SC 2012 license, all VMs running on that same virtualization host are covered automatically with a SC 2012 license, no matter what SC 2012 based workload you run on them.

SQL for free?
And yes, SQL Server comes for free for the System Center 2012 Product when those SQL Servers only run SC 2012 based workloads AND the Standard edition of SQL Server is used.

So what?
The nice thing here is that you don’t have to be lean & mean anymore when rolling out SCOM 2012 Management Servers. So when your design tells you to roll out 3 of them, add an additional one. Yes, it will take resources like disk IO, CPU and RAM. But that goes for any other VM as well of which many new ones are deployed on a weekly basis.

But why? Because we can?
No. There is more to it. Now with SCOM 2012 you can monitor network devices way much better compared to SCOM 2007x. However, other MPs require SNMP to be present on at least one of the SCOM 2012 Management Servers.

For network monitoring SCOM 2012 uses a SNMP trap module of it’s own. And yes, the SNMP feature of Windows Server 2008 R2/2012 and that particular SCOM 2012 module don’t work well together.

In cases like these it’s better to use at least one dedicated SCOM 2012 Management Server, exclude it from network monitoring, and install the SNMP service on that server for those special MPs, like the SAN MP of HP for instance.

This way you know for sure these two components won’t bite each other, enabling you a more stable SCOM 2012 environment.

When designing a SCOM 2012 environment I use this new rule of thumb for the quantity of needed SCOM 2012 Management Servers:

(Required SCOM 2012 Management Servers based on quantity of monitored objects + future growth) + 1 additional SCOM 2012 Management Server = Total amount of SCOM 2012 Management Servers to be rolled out.

This way you know you have a SCOM 2012 environment in place which can be used in a smart manner with per Management Server a dedicated additional role, like communicating with the framework used by HP for monitoring their SAN solutions for instance.

For more information about the System Center 2012 Product license model, check out this series of postings I wrote about it.


Jonathan said...

Can you provide more context and/or resource links around your statement:

"For network monitoring SCOM 2012 uses a SNMP trap module of it’s own. And yes, the SNMP feature of Windows Server 2008 R2/2012 and that particular SCOM 2012 module don’t work well together."

Marnix Wolf said...

Hi Jonathan.

Yes I can. For instance the HP Storage MP requires the SNMP service to be installed on one of the SCOM Management Servers. But as stated here http://technet.microsoft.com/en-us/library/jj656656.aspx this might cause issues.

I have seen issues where network monitoring and discovery turned sour because of the SNMP service being installed on a SCOM Management Server.

After removal of this Management Server from the Resource Pool responsible for network monitoring and not using this server any more for the discovery of network devices, all was okay again.

Therefore I Always excluded those Management Servers from network device discovery and monitoring.