November 11, 2011 at 3:16 am
Hi, Im a DBA at a new company and have been charged with the task of setting up High Availability. We currently lease one SQL Server box (dedicated physical machine running 2008 web edition), and have 3 VM's running our web sites.
With our current setup and version (web edition) I could simply lease another box, create a private lan between the two and set up log shipping. Unfortunately our requirements are for automatic failover with (zero to no downtime) and more specifically - clustering.
I've never set up a 2 node cluster (Windows, SQL) and am trying to get to grips with the kit I need. Im quite confident that once the windows cluster is in place; I can deploy SQL on to it.
Could somebody give me some pointers as to what I should be asking for (very general I know 🙂 ) in terms of:
How many boxes in total (2 for each node, do I need a witness and a DNS box too [4 in total])?
SQL Version (I think standard would be suffice)
Thanks in advance
November 11, 2011 at 3:26 am
Before Installing Failover Clustering
November 11, 2011 at 3:31 am
SQL Version (I think standard would be suffice)
Failover clustering is supported in SQL Server Enterprise and SQL Server Developer, and, with some restrictions, in SQL Server Standard.
November 11, 2011 at 3:46 am
How many boxes in total (2 for each node, do I need a witness and a DNS box too [4 in total])?
Each node is a "box", so for a two-node cluster, you need two (identical) servers. Witness servers are for (some implementations of) mirroring, so you don't need one here. You can use the same DNS server that every other server in your domain does.
Dev (11/11/2011)
Failover clustering is supported in SQL Server Enterprise and SQL Server Developer, and, with some restrictions, in SQL Server Standard.
I'm not aware of any restrictions in Standard Edition specific to clustering (maybe the number of nodes you can have in the cluster?). I'm not saying there aren't any, but if there are, they haven't stopped my organisation implementing multi-instance clusters on Standard Edition.
John
November 11, 2011 at 3:47 am
NickBalaam (11/11/2011)
With our current setup and version (web edition) I could simply lease another box, create a private lan between the two and set up log shipping. Unfortunately our requirements are for automatic failover with (zero to no downtime) and more specifically - clustering.
Zero downtime and clustering don't usually go together. There will be downtime during a cluster failover. May not be much (minute or 2) but it will be there. Also, clustering has a single point of failure - the storage. So for true 0 downtime no matter what (which is actually near-impossible), you're going to need more than just clustering.
How serious is that 'zero downtime' requirement? To give you an idea, the 5 'nines' (99.999% uptime, 5 minutes or so downtime a year) is extraordinarily expensive to actually pull off.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
November 11, 2011 at 3:48 am
John Mitchell-245523 (11/11/2011)
I'm not aware of any restrictions in Standard Edition specific to clustering (maybe the number of nodes you can have in the cluster?).
Exactly that. Standard limits to 2-node clusters. (which honestly isn't that much of a problem unless you're doing a large multi-instance cluster) whereas Enterprise supports OS maximum.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
November 11, 2011 at 4:38 am
Thanks for the comments.
2 mins (roughly) downtime is acceptable, we currently have no High Availability, and with our current set up (web edition) im limited to logshipping (better than nothing but more manual failover)
The restriction of 2 node support in SQL Standard does not pose a problem.
In short, I don't need a witness box, but I do need to get some cluster compatable shared storage, and two identical boxes to form the 2 node cluster.
Thanks very much for advising on what is a general question.
November 16, 2011 at 2:44 am
NickBalaam (11/11/2011)
Hi, Im a DBA at a new company and have been charged with the task of setting up High Availability. We currently lease one SQL Server box (dedicated physical machine running 2008 web edition), and have 3 VM's running our web sites.With our current setup and version (web edition) I could simply lease another box, create a private lan between the two and set up log shipping. Unfortunately our requirements are for automatic failover with (zero to no downtime) and more specifically - clustering.
I've never set up a 2 node cluster (Windows, SQL) and am trying to get to grips with the kit I need. Im quite confident that once the windows cluster is in place; I can deploy SQL on to it.
Could somebody give me some pointers as to what I should be asking for (very general I know 🙂 ) in terms of:
How many boxes in total (2 for each node, do I need a witness and a DNS box too [4 in total])?
SQL Version (I think standard would be suffice)
Thanks in advance
See my 3 part guide at this link[/url] to help you understand what is required. If you have any further questions post back.
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