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Michael Valentine Jones
Yak DBA Kernel (pronounced Colonel)
7020 Posts |
 Posted - 2009-05-20 : 17:05:50
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| I am considering setting up an active\active cluster with a SQL Server instance assigned to each node, with the other node as the failover node for each instance. I am looking at running 64-bit SQL Server 2008 Enterprise Edition on 64-bit Windows 2003 Enterprise Edition.Will the two SQL Server instances dynamically adjust their memory usage if they are both running on the same node, or would I need to do this manually in a failover situation?Any good reasons not to do the active\active cluster or problems I should watch out for?CODO ERGO SUM |
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tkizer
Almighty SQL Goddess
38200 Posts |
Posted - 2009-05-20 : 17:09:23
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| It isn't done dynamically. It is recommended that you configure each instance so that if all of the instances are running on the same node that you aren't over the memory limits of that node. So in a 64GB memory environment with two instances (one on each node), you'd perhaps configure each instance to use a max of 30GB (to give the OS some memory).Tara KizerMicrosoft MVP for Windows Server System - SQL Serverhttp://weblogs.sqlteam.com/tarad/Subscribe to my blog"Let's begin with the premise that everything you've done up until this point is wrong." |
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TRACEYSQL
Aged Yak Warrior
594 Posts |
Posted - 2009-05-20 : 18:17:24
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| I would go directly to WINDOWS 2008 for SQL 2008 as the cluster setup is easier with new wizards.Wouldn't run two instances on same box - just one box for each instance if you can. |
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dinakar
Master Smack Fu Yak Hacker
2507 Posts |
Posted - 2009-05-20 : 22:13:32
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| SQL 2008 handles to OS memory pressure much better than SQL 2000. Earlier SQL Server did not release memory until the OS was really really dying.. but in SQL 2008, if you had 2 instances running on same machine and if the MAX server memory was set SQL will still release some memory if the instance isnt using all the memory it acquired. Bottomline, you are good MVJ.Dinakar Nethi************************Life is short. Enjoy it.************************http://weblogs.sqlteam.com/dinakar/ |
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TRACEYSQL
Aged Yak Warrior
594 Posts |
Posted - 2009-05-29 : 22:33:30
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| Do you still need to do the lock in memory for SQL 2008 and set up the max memory setting. SQL 2008 on Windows 2008 . |
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flotsam7jetsam
Starting Member
1 Post |
Posted - 2009-10-19 : 16:52:46
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| Dinakar Nethi's finding's are what I've heard as well and even seen demoed to some degree at TechEd. Problem is I cannot find any supporting documentation for this other than blogs and I'm trying to prove my case to upper management for our High Availablity solution. In fact there's lots of documentation for older versions of SQL that say you must set hard max memory limits for SQL Servers in an Active/Active cluster. Might you have any documentation for SQL 2008 that supports your findings Dinakar? |
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tkizer
Almighty SQL Goddess
38200 Posts |
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SQL 2008 Active\Active Cluster