how many number of nodes

Hi,
I am a newbie to Clustering. I dont know how to decide how many number
of nodes I need to install. For example, if I have 4 SQL database servers
and all 4 servers should be highly availabe and automatically failover. In
this case how can I configure clustering?
Up to 5 or 6. If you want one instance per server - due to load, then 4 is
the min. 1 or 2 boxes for failover, depending on your needs.
Cheers,
Rodney R. Fournier
MVP - Windows Server - Clustering
http://www.nw-america.com - Clustering Website
http://www.msmvps.com/clustering - Blog
http://www.clusterhelp.com - Cluster Training
ClusterHelp.com is a Microsoft Certified Gold Partner
"Bharathi" <NoSpam_BB@.hotmail.com> wrote in message
news:OWOGrVtXHHA.3952@.TK2MSFTNGP04.phx.gbl...
> Hi,
> I am a newbie to Clustering. I dont know how to decide how many
> number of nodes I need to install. For example, if I have 4 SQL database
> servers and all 4 servers should be highly availabe and automatically
> failover. In this case how can I configure clustering?
>
>
|||There are two general configurations: N + I and failover pairs.
For N + I, you would have N active nodes and I inactive. Each of the active
nodes would be paired with one or more of the inactive nodes. If you had
multiple active node failures then the inactive node(s) would have to have
enough processing power to host each of the failed configurations.
For the failover pairs, say you had, in your case, servers A, B, C, and D.
Then you would install each of the instances to a pair: Instance 1 to A and
B, Instance 2 to B and C, Instance 3 to C and D, and Instance 4 to D and A.
All would be active, each capable of running at least 2 instances for
maintenance or due to failure.
I prefer the N + I model because it is easier to manage, but the other works
well too.
Sincerely,
Anthony Thomas

"Bharathi" <NoSpam_BB@.hotmail.com> wrote in message
news:OWOGrVtXHHA.3952@.TK2MSFTNGP04.phx.gbl...
> Hi,
> I am a newbie to Clustering. I dont know how to decide how many
number
> of nodes I need to install. For example, if I have 4 SQL database servers
> and all 4 servers should be highly availabe and automatically failover. In
> this case how can I configure clustering?
>
>
|||For N+I, N+1 is a common practice with a single node acting as the failover
for all the N active nodes. In this case, you basically design to protect
again a single node failure and consider two or more nodes failed at the same
time as not in scope or as a low probability scenario in which multiple
instances will be running on the same failover node with degraded
performance. The main advanatge of N+1 (as opposed to multiple pairs of
tw-node clusters) is the cost saving in hardware (i.e. fewer servers).
We don't configure N+2 or N+3 and so on. But somebody else may chime to
share their experience on having two or more spare nodes.
Linchi
"Anthony Thomas" wrote:

> There are two general configurations: N + I and failover pairs.
> For N + I, you would have N active nodes and I inactive. Each of the active
> nodes would be paired with one or more of the inactive nodes. If you had
> multiple active node failures then the inactive node(s) would have to have
> enough processing power to host each of the failed configurations.
> For the failover pairs, say you had, in your case, servers A, B, C, and D.
> Then you would install each of the instances to a pair: Instance 1 to A and
> B, Instance 2 to B and C, Instance 3 to C and D, and Instance 4 to D and A.
> All would be active, each capable of running at least 2 instances for
> maintenance or due to failure.
> I prefer the N + I model because it is easier to manage, but the other works
> well too.
> Sincerely,
>
> Anthony Thomas
>
> --
> "Bharathi" <NoSpam_BB@.hotmail.com> wrote in message
> news:OWOGrVtXHHA.3952@.TK2MSFTNGP04.phx.gbl...
> number
>
>
|||I need to setup up N+1 cluster.
We have 4 win2003 Enterprise servers: A, B, C, D. I need to install one
instance of sql2000 onto each machine except D which will be the passive
node. My questions:
1. What are the steps to setup a 4-node cluster? (I have done 2-node
cluster.)
2. If each active node uses 4 letters for shared drives, the total number of
active nodes is limited to < = 6, correct?
Thanks a lot.
Jin
"Linchi Shea" wrote:
[vbcol=seagreen]
> For N+I, N+1 is a common practice with a single node acting as the failover
> for all the N active nodes. In this case, you basically design to protect
> again a single node failure and consider two or more nodes failed at the same
> time as not in scope or as a low probability scenario in which multiple
> instances will be running on the same failover node with degraded
> performance. The main advanatge of N+1 (as opposed to multiple pairs of
> tw-node clusters) is the cost saving in hardware (i.e. fewer servers).
> We don't configure N+2 or N+3 and so on. But somebody else may chime to
> share their experience on having two or more spare nodes.
> Linchi
> "Anthony Thomas" wrote:

How limiting is MS SQL?

I'm trying to decide whether MS SQL will allow me to accomplish the following objectives at no cost, or whether I'd eventually have to pay for an MS SQL upgrade to accompish my objectives.

I have big, unrealistic dreams. I want to create a humorous newsblog into which I would post more than a dozen times a day. Most of the posts would have large photographs. Presumably, I'd archive the posts by subject and ranking and 'most viewed," etc., using a database.

1) Will the space limitations of the MS SQL Express edition be an issue after a while?

2) Could I hire a web developer to help me from a remote location, once the website is large enough to warrant expansion? Or does the MS SQL Express edition allow only one user? I read something I didn't understand about CPU restrictions.

3) I'm confused because web hosts advertise the availability of MS SQL databases on their server...so does that mean I wouldn't have to buy an upgrade if it became neccessary? (I know, I'm shockingly uneducated.)

4) I'm going to buy Office 2007. Is it important to purchase a package that includes Microsoft Access, given my goals?

5) Any other thoughts in plain english on how the MS SQL express edition imposes limitations....basically, I don't understand how MS SQL Express might limit me down the road if the site were actually a success. What would have to happen before I would be forced to spend a lot of money on an upgrade later?

I'm almost completely new to computing. I've read a bunch of criticisms of MS SQL Express on internet forums that I didn't understand, but that really made me worried about my decision to go with Microsoft Products and Asp.net web hosts. (I understand some people have an irrational dislike of Microsoft, but there was A LOT of bashing.)Hi.

1. 4 GB is quite a lot of data but large photographs can quickly eat up database space. One option you might have if you're working with a web developer is to instead use disk space for the actual image rather than stuffing it into the database. You'd want to give each a random name and just store that name in the database.

2. Yes you could hire a web developer to work on it from a remote location. SQL Server 2005 Express is not limited in the amount of users that can interact with it. In fact for most things it differs very little from the full Enterprise edition. It does limit you to a single CPU instead of being able to utilize multiple CPUs. For a little more information on what you can do with this edition checkout:
http://www.sqlmag.com/Article/ArticleID/49736/49736.html

and

http://technet.microsoft.com/en-us/library/ms345154.aspx

3. If you're hosting somewhere that offers to host your SQL Server database that means you don't need to worry about SQL Server 2005 Express at all. You'll develop with that locally and then provide them with the database files. It will instead run on their shared server along side other customer databases.

4. As far as Access is concerned, if you're using SQL Server Express 2005 you really wouldn't have much use for Access at all. It certainly isn't something you'd want to build this site upon...

5. Like I said before SQL Server Express doesn't differ significantly from the full Enterprise product. There are some additional features missing that most non-Enterprise uses probably won't miss like Analysis, Notification, and Integration services. If you checkout SQL Server 2005 Express with Advanced Services (http://msdn2.microsoft.com/en-us/express/bb410792.aspx) you even get Reporting Services (which is cool). Other than that it is limited to a single CPU rather than multiple and yes the database size can only be a maximum of 4GB and it can only use 1 GB of ram for some things but overall it comes down to usage. Aside from storage space nothing you've described would seem to push Express beyond its limits.

Hope this helps you with your decision!
|||Wow! A lightening quick response on a holiday. Thanks!

I'm not as lightening quick as your response. I'd like to put your response in my own words, to see if I got it right.

1. Rather than storing the photo in the database, I could store a link to the photo. If I understand you correctly, that should allay my concerns regarding disk space.

2. I read the links you provided, and I understand that I could have a web developer work on the website from a different location. I wasn't sure I understood the following, however:

"It does limit you to a single CPU instead of being able to utilize multiple CPUs."

--How does this limit me as a practical matter? I looked at the resource you provided, and it said:

"SQL Server Express can install and run on multiprocessor machines, but only a single CPU is used at any time. Internally, the engine limits the number of user scheduler threads to 1 so that only 1 CPU is used at a time. Features such as parallel query execution are not supported because of the single CPU limit."

I take it that the CPU limitation means that the web developer and I couldn't work on the database at the same time. But, umm..."user scheduler threads"... I'm not sure I've understood this correctly. Do I have it right?

3.1 So, here's a few excerpts from a web host service ad. I substituted the name WebHost.net in place of the actual host name.

"WebHost.NET offers Microsoft SQL Server 2005 database hosting, the next-generation of robust enterprise level database as an optional addon to our base hosting plan."

I understand that you don't represent the web host, but from what you can see, am I correct in understanding that if I were to buy the above package, I wouldn't have to worry about keeping within the 4 GB and 1 CPU limits? Or any other of the (relatively modest) MS SQL Express limitations?

3.2 Here's another excerpt:

"Connect to your MSSQL database with your choice of tools including Enterprise Manager, Query Analyzer, or Visual Studio.NET, directly through ASP or ASP.NET applications."

So, given the above, do some web host allow people to use Visual Web Developer's "Solutions Explorer" feature to make use of the MS SQL database stored on the Web Hosts' computer?

3.3 Is it reasonable to say that I could use the MS SQL Express edition for now, and then buy the MS SQL through my web host for a few extra bucks a month if the (relatively minor) limitations of MS SQL Express start to bother me? I wouldn't have to shell out $1000+ to buy a non-Express version of MS SQL?

I'm definitely willing to pay a little extra to be able to use Microsoft products front to back, since the idea seems to be that they're easy for a novice to use, stable, and integrated with one another.

4. The only answer my tiny little mind allowed me to grasp. Thanks!

5. "It can only use 1 GB of ram for some things but overall it comes down to usage."

5.1: I think I understand that the 1GB of ram limitation is not serious, but I don't understand why. I read in the material you referenced:

"The 1 GB RAM limit is the memory limit available for the buffer pool. The buffer pool is used to store data pages and other information. However, memory needed to keep track of connections, locks, and so on is not counted toward the buffer pool limit."

Buffer pool? Connections? Locks?... Wookies? Chewbacca? Endor?

As a practical matter, does the 1GB limitation mean that I can't use all of my computer's RAM to work on the database with MS SQL? I obviously just don't grasp the significance of the 1GB ram limitation.

5.2: you wrote: "Overall it just comes down to usage."

I assume you meant that I can't use more than 4 GB of storage space? I just don't get what you meant. (My fault, not yours.)

6. Additional question: I (attempt) to use the 2008 Visual Web Developer Express edition, because somebody told me it writes far better code than the 2005 edition. Does the fact that I'm using the 2008 edition of VWD mean I can't download and use the MS SQ Express 2005 edition, since they are from different years? I haven't downloaded the database yet.

Thanks so much for your patience!

--Tim (randomasdfguy)
(in the preview pane, I saw that part of my answer was in a very small font, and I don't know why, and I couldn't manage to fix it. Sorry.)
|||Hello again Tim.

1: Yes storing the photo locally and including just a link in the database will not only save you space but can also improve overall performance of your site.

2: CPU Limitations: Well only using a single CPU basically limits performance but from the usage you described I seriously doubt this will impact the usability of your site. This CPU limitation really only relates to the processor installed on the server and in no way impacts how many users can connect to it so you and your web developer can definitely connect simultaneously along with all of your users.

3.1: Yes generally when a website says it offers SQL Hosting that means they own the license to the SQL Server and it is probably going to be Standard edition so the limitations imposed on the Express editions would not apply whatsoever. I would call their sales department to make sure but I've hosted several places and that was the case...

3.2: Yes thats what that means...that you can connect to your databases in Visual Studio or a variety of other host applications.

3.3: Absolutely. That is exactly how I would do it. Use the freebie for now and when and if performance degrades or you start running out of space upgrade. I doubt you'll hit either of those scenarios for a long time.

5.1: The 1 GB RAM limitation really just impacts some portions of performance and again given your usage I doubt you'll ever notice.

5.2: Ummm...by usage I mean how you intend to construct your website and how it is going to utilize SQL Server. A lot of it is up to the skill of the developer to make his site more efficient. There are tons of great techniques in ASP.NET to help you run in a very efficient manner. Here are a few performance related links to get you started:

http://msdn.microsoft.com/msdnmag/issues/05/01/ASPNETPerformance/
http://msdn2.microsoft.com/en-us/library/ms998549.aspx

6: Oh you can definitely use SQL Server 2005 Express Edition with 2008 Visual Web Developer Express Edition no question about it.

Please let me know if you have any other questions and I'll do my best to answer them...

Christopher
|||Christopher,

Thanks a million for your help! It is sincerely appreciated!