What is causing our ecommerce server downtime?

  • upwordz
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Post 3+ Months Ago

We are running IIS 5.0 with Windows 2000 server on dual 2.4 GHz Xeon Processors with 1 GB of RAM and a 10 Mbit half duplex network connection on a dedicated box hosted with Verio Hosting.

Over the past year we upgraded to this machine because about once a month we would encounter down time and severe lag for a period of minutes and or hours on and off. Verio confirmed that traffic / bandwith was not the problem.

We were able to see in the task manager that our ecommerce application Softcart (from Mercantec) was eating up all the available RAM. The program runs on demand when a visitor uses the navigation on our site, starts a shopping cart or checks out. However, the application usually processes each request and then closes. It appeared during times of severe lag that the processes were not closing. Since we rewrote our URLS about two years ago which removed the application out of the URL, we now use Perl scripts to talk to the Softcart application. So, for each instance of the softcart application that we saw in the task manager, we also saw an instance of Perl. One of the theories that has some evidence to support it is that we have noticed search engine bots present during several of the lag periods. Since our site is dynamic and relies on Softcart to access the flat file database of more than 6,000 products, we thought it was possible that the bots were overwhelming our server. Whether it was Softcart, Perl or the processor we didnt know. So we upgraded to the server as described above and the problem has not gone away (though it is still possible that we need a faster server). We did have Verio test opening our connection to 100 Mbit full duplex, but the problem did not go away. We have since instituted a robots.txt file to keep the robots from visiting our site and for the past two days that has appeared to work. However, we obviously want to be a bot friendly site and Google has indexed most of our pages at this point so at least they have found a way to not take our site down.

We are currently trying to find some process management software that will allow us to track memory allocation and running time to all the processes on our server. If anyone has any software suggestions or suggestions of any other kind please let us know.
  • Anonymous
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Post 3+ Months Ago

  • ATNO/TW
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Post 3+ Months Ago

I guess my question would be why are you running 10Mbps half duplex instead of 100Mbps full duplex?

I would see that as a potential cause for slowing things down, although don't know why it would affect your RAM like that.
  • upwordz
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Post 3+ Months Ago

Thanks for your post! Well, while I do not remember the difference in price, I believe it was substantial and according to the information we had at the time (this was about 6 months ago), we didnt use enough bandwidth to justify the larger pipe, it would largely go unused. On top of that, when the site is not lagging, it runs quite quickly. We have had customers tell us in surveys that one of the things that stood out to them was the speed of the site. This problem only comes once in a while. We are currently looking at purchasing some performance monitoring software such as http://www.hyperic.net/products/manager ... gement.htm and http://www.sentry-go.com/qm-iis-web-monitoring.htm in the hope that we can pinpoint if our ecommerce application is choking on a request, or if Perl may be doing so etc. Once we have something set up, we plan to remove a robots.txt file we put in place this weekend to keep bots out (thinking that perhaps a bot was putting our system under a crush). Hopefully then we can get more information the next time this happens and confirm that it was a bot or what process was failing...
  • Ragnar78
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Post 3+ Months Ago

Its probably a relation between DB that cause this traffic Jam...

Actually, i was working on PeopleSoft, and sometimes while i tried to retreive Data with unions and selects in selects, the request never retreived info...or more acurate...it retreived info in a REAAALLLL slow way.
So what i think you should do is change the architecture of the DB like inserting new indexes or so...
That's my opinion, though i'm not sure i'm totaly correct...
As for what we did, we made a copy of a table from one server to another update regularily, that faicilitated the transfer of data...plus the queries has been tuned...
  • UNFLUX
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Post 3+ Months Ago

this is better suited in hosting :)
  • Carnix
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Post 3+ Months Ago

This doesn't sound like a bandwidth issue. If IIS is getting crammed, it will slow down significantly... Eventually, sessions time out as users are dropped, and it is able to recover itself and release memory that expired sessions have freed up.

Sounds like a memory leak to me. You probably can't hack the ecommerce software to check, but are you sure that the database connections are being closed properly? A sure fire way to smack down IIS is to not close recordsets and database connections, and set them = nothing. I mean really... IIS is pretty good at garbage collection, but not when it comes to databases.

That's the first thing I would check. There are some other memory leak possiblities in ASP code, but db connection is the #1 culprit.

.c
  • rDolay
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Post 3+ Months Ago

If your servers going to down without any error at the same times period, it the meaning of that one of the CRON JOBS makes the server overload and hangs at those times., so search your automated cron jobs for your server and sure that your frontpage + logalizers wont suck on the updates via cronjobs by manipulating entries without deleting old files and if you have this kind of problem its hard to fix little bit and i cant tell anything more about the Windows Servers.
  • ATNO/TW
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Post 3+ Months Ago

I still go back to my original question. 10 Mbps half duplex vs. 100Mbps full duplex is going to slow you down. Period.

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