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Dinky
Starting Member
37 Posts |
 Posted - 2009-09-10 : 00:28:29
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| Env: Windows Server 2003SQL Server 2005 - 2 node clusterDell SANI have 2 filegroups (100 gb and 200 GB) for the db and need to setup Active Active Cluster. If Active Active is not really buying anything extra (load balacing, high availablity), Active/Passive should be fine too.I have gone through few links on web, will prefer direct answers. Thanks.Questions:1. In one line. What is the difference between SQL Active/Passive and Active/Active Cluster2. Do both type of clusters automatically/transparently take over in case of one node failure.3. Is Active/Active Cluster is actually a set of 2 Active/Passive Cluster databases with some kind of SQL replication between 2 databases.4. Do I need 4 seperate disks/paths for file groups - 2 100 gb and 2 200 gb disks - one set each for 2 node instances. OR both instances are going to be reading writing to same 1 physical set of SAN disks |
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stevechristin
Starting Member
2 Posts |
Posted - 2009-09-10 : 03:49:20
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| 1. In one line. What is the difference between SQL Active/Passive and Active/Active ClusterIn Active/Active both servers handles requests. You have to pay for 2 servers.2. Do both type of clusters automatically/transparently take over in case of one node failure.Yes. That is the essence of clustering. 3. Is Active/Active Cluster is actually a set of 2 Active/Passive Cluster databases with some kind of SQL replication between 2 databases.No. They share the same storage.4. Do I need 4 seperate disks/paths for file groups - 2 100 gb and 2 200 gb disks - one set each for 2 node instances. OR both instances are going to be reading writing to same 1 physical set of SAN disks There should be a common/shared storage. www.branegy.com |
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Dinky
Starting Member
37 Posts |
Posted - 2009-09-10 : 21:09:03
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| So is it that:Active Active are 2 instances of the same db connected to same physical storage drives. So when 2 drives (2 filegroups for the db instance) are D and E and failover happens, 2nd node will also see the same 2 drives (D and E). Active/Passive : At anytime time only active node (machine) will have 2 drive visible. On Passive node, 2 drives will not be even visible.Active/Active : At anytime time both/all active nodes (machine) will have both drive (D & E) visible and accessible read write. So Active Active is transparently doing the load balacing without any additional setup? DB Calls automatically get routed to one and only of the nodes.Is it not that the Active/Active configuration is similar to two SQL server instances running independently.There will be two seperate databases and on failure of one instance other instance wont be able to cater to the requests designed for first instance, Thus providing no extra benefits from cluster.The question is how to take benefits of the load balancing features in Active/Active configuration. |
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kenchee
Starting Member
49 Posts |
Posted - 2009-10-15 : 18:21:17
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| Hi Dinky, With an Active/Active config, you are right in terms of it being two SQL Server Instances running independently, however if one of the node fails, the sql instance that is on that failed node will be moved to the other node. This will mean that the node that is still running will be handling two sql instances instead of one. Bear in mind that when the SQL instance is failing over to the other node, it's basically a stop the sql instance, then move the sql instance to the other node and then starting up the sql instance again. There is no load balancing feature as such in the any sql cluster configuration. it's use basically as a redundancy option. |
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SQL Server 2005 Cluster setup questions