Please advise on best setup for multi-server web application.

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Posted by trfl, 05-28-2012, 09:28 PM
Hi Everyone, I asked this question on another forum and they were not very nice. I am just seeking a general answer from a professional. I am a developer, not a network admin in any way, shape or form. I am currently developing an application that a niche market will use to run their business. My main concern is stability and fail over. There will not be enough requests at the beginning to overload even a small server. This will be a .net 4.0 application running SQL Server 2008. Basically my question is, what is going to be my best setup? It is important to note that my host will be doing a colo for my servers. I will also be paying them an additional monthly fee to manage my servers and also to use some of their equipment such as their firewalls, backups and shared mail servers. My initial thought is that I may need two small web servers and two small database servers. I thought two of each because if one went down, the other could carry the load until fixed. I believe I will also need a load balancer for this. Is this the best solution? If so, how will my storage work? Could there be a RAID10 central storage point that all servers could read from? Coming from a programming background, it doesn't seem to make sense the application files and database files would be duplicated across servers. I will be having discussions with my host within the next week or so and they will be providing their recommendations. I just wanted to get another opinion prior to discussing with them. Also I want to keep the initial setup for this under $10k, does that sound feasible? Any input is greatly appreciated and if there is any additional information needed, please let me know. Thanks!
Posted by sbradk, 05-29-2012, 09:56 AM
The first thing I'd consider for a start is a Cloud Server. A well architected cloud solution will already have redundancy and scalability (for *at least* small bursts) built-in to the solution. Beyond that, I'd look at a front-end web farm for the content nodes. Either replicating with something like DFS, or using a centralized content storage location. For the back-end databases you could either cluster them or use another solution like DB mirroring... both having some pros and cons so the best solution would depend on your needs. Hope this helps.
Posted by Tomcatf14, 05-29-2012, 11:58 AM
Well, you could start with 2 x cloud nodes with a subscription to Load Balance services. To sync the data on both servers, you could use Windows clustering and MSSQL replication. The least complicated way would be deploying fast backup s/w on the primary node and keep backing it up to the secondary node. Of course, this would depend on your tolerance on data lost. A good backup/imaging s/w could run an image of your server every 10-15 mins w/o sweat. If you have the budget, a dedicated server as the primary node with a cloud node as the secondary/backup node sounds like a better idea.
Posted by trfl, 05-29-2012, 01:29 PM
Thanks to both of your for you fast responses. Please forgive my ignorance as I am not real knowledgeable in this field, especially cloud computing. You both have mentioned getting a cloud server. What is the difference between a cloud server and a standard dedicated server? Would this setup be my own cloud network or would I just be a part of my provider's cloud network that the rest of their clients are on? Tomcat: Where you mentioned that I could start with 2 cloud nodes, is that two cloud servers? You also mentioned syncing the data, to me that means having a copy on both nodes. Is it possible to have a central location that they both can read/write to rather than duplication? You also mentioned load balancing services, is that a service provided from an outside source or are you referring to buying the physical load balancer? The max budget I would have for getting everything setup and in place would be about $10k, does that sound like enough to do the latter solution you mentioned? Finally, from what I have read about cloud computing, it seems it is great for handling spikes in traffic, which is good. However, isn't it also true that if the primary node's motherboard or power source goes out, or the primary node is restarted, the application will still go down. Basically my question is does a cloud provide redundancy if the primary node goes down? Again, thank you for all your help.
Posted by Tomcatf14, 05-29-2012, 03:32 PM
Yes, you could get a cloud hosting from your favorite provider. Usually, the bigger provider do provide load balance service as well. If you want both nodes to read/write from the same location, the setup will be more complicated and usually require a SAN which would add up to the cost. A dedicated SAN could be very costly and you will definitely break the $10k budget.
Posted by sbradk, 05-29-2012, 03:38 PM
A cloud server is a virtualized server instance running on a cluster of hardware. You can run your own dedicated (private) cloud or run on another host's public cloud infrastructure. Even on public cloud space the network is VLAN'd and the infrastructure is (or at least should-be when done right) segregated and isolated for security purposes. When you run two nodes (physical dedicated or cloud dedicated) you need to deal with the content. You can synchronize with something like DFS, or you can use a centralized content store (then though you also need to make that redundant). For load-balancing, if you go that route, you can use either hardware load balancing like F5 or Foundry, or you could go with software options, like Microsoft's ARR (free, and surprisingly it scales well). $10k... per month? Annually? If a cloud node goes down, and your cloud server happens to be tied to that node at the time, then yes you will see downtime. But the downtime is limited to approximately the time it takes to reboot because the cloud server will automatically power-on to another node. So if you can tolerate perhaps a couple of minutes downtime in an emergency, this is fine. If not, then you are more likely looking for a web farm of multiple notes (again, physical or cloud - doesn't matter much). HTH
Posted by Collabora, 05-29-2012, 03:44 PM
Forget about "Cloud." Stay in the direction of OP. Get a couple of servers and create a cluster using NLB.
Posted by sbradk, 05-29-2012, 03:47 PM
Thumbs down on NLB. Way too many issues with it.