Hi Everyone, I've seen several posts outlining ways of aiding in over stressed servers on this forum and wondered if I could get some possible options of action for the setup I'm currently working under. We have 3 Windows Servers, 1 SQL Server Database, 1 Server for hosting web services on, and 1 for our website. However we've been experiencing a huge traffic increase recently with our Web Service. My initial temporary fix with my hosting provider was to make an additional A record and point this additional A record to the web server (which isnt overloaded) to handle 50% of the calls for the time being. Without buying another server (ukfast seem to be so over priced), what other options do I have? How much of a bad idea would buying another server from elsewhere (cheaper), and adding a further A record for the 3rd location, spreading the traffic over 3 servers. They're quite high spec servers so its bewildering me the slow speed occuring. If you guys want to know any details about the setup I'll happily try and get them to you.
More details would be helpful to readers. The minimum would be: 1. High spec servers. Please define. What is high spec to you, may not be high spec to others. 2. Where in the chain of web->services->db do *you* think the whole thing is falling down and why? Real observed performance data would be helpful. 3. How do you think running a round robin record is going to help you? And what does this record point to? A com+ server?
The web server is an Intel Xeon 3.0GHz with Windows Server 2003, 2GB Ram, the XML/Web Services server is a Dual Xeon 2.8 Ghz 2GB running Windows 2003 also. The SQL Server is same spec. They all share a managed firewall at the Hosting Location, so I'm unable to give any specifics on that. However, the web server wasn't suffering any load issues so we setup an instance of the web services on the Web Server and did the round robin record to point between the XML server and the Web Server, so it spread the requests between the 2 servers. (I'm aiming to keep the SQL Server secluded from outside). I believe that the weak point seems to be the XML Server being overloaded with requests. http://www.robertharvey.co.uk/aa/241.gif http://www.robertharvey.co.uk/aa/242.gif http://www.robertharvey.co.uk/aa/243.gif (As I haven't posted much yet it wont allow me to post these as proper links) If you want to see specific data. Hope that's enough data to help.
Do you have any bandwith limitations between your servers ? I am suprised that the bandwith between SQL and XML is not higher...
I believe the .243 has a 1MB limitation, and the others both have 3MB limitation. The web server itself has some hard drive issues from discussing it with my IP, bad clusters etc. So I believe its going to be cloned and replaced in the next few days which I'm hoping will help.
Well, I can't make head nor tails out of the bandwidth graphs. I was hoping for performance monitor data. However, I believe Thomas the thread of something there. If it were me, I would turn two of the servers into web+xml leaving sql alone. You might want to investigate the builtin WLBS. This would require 3 public ip's. Then, I would run the xml->sql connection over a backend network on a private switch using private ip space, ie. 192.168.x.x. Any recent 8 port switch should do the trick. The point being to eliminate the bandwidth restrictions on that path and to eliminate any delays from the firewalling burden. The firewalling is not necessary provided the public facing nics are secure. The only connections on the private network are between your machines. Your hardware cost would be a three nics, three cables and a switch. You can eliminate the switch if your host will configure a private vlan for you on their switch. If you do this, be *very* sure that the vlan is indeed private and not accessible from the internet. Also make sure that it is unthrottled or it is a useless exercise. It should also not be chargeable bandwidth as it is only flowing between your machines. You still need to look at performance monitor logs. BTW, a failing hard drive can also cause slowdowns.
Hi Plum, I have already made the web/xml servers both handle the web services via a round robin method, getting the hosting company to put a private switch in seems to result in them quoting stupid cost figures at me. I may need to post a new thread asking about the best way to implement web services as it seems to keep coming back to speed issues with that over anything else.
Take a look at the cpu usage. If it is low at the time of congestion, then it is likely bandwidth for the xml->sql connection. If the host is giving you fits about the switch, then try for the private unthrottled vlan. Do they even know how to do this? I keep on forgetting that not everyone gets to walk into the data center and just sling equipment around as they please Oh, about web services. I have no use for three tier architectures. Xml is a solution looking for a problem. Sql gives you the data, iis serves the data. At the most, I transform to csv's.
I will ask them the question, I wouldn't know myself! I will check everything out and let you know what I find. Thanks for all the help/advice.