Scaling Server Performance
An anonymous reader writes "When Ace's Hardware's article Hitchhiker's Guide to the Mainframe was posted on Slashdot, they got 590,000 hits and over 250,000 page requests during one day. This kind of traffic caused only a 21% average CPU load to their Java-based web server, which is powered by a single 550MHz UltraSparc-II CPU. In their newest article, Scaling Server Performance, Ace's Hardware explains how this was possible."
Are we supposed to be impressed with a computer that can serve 8 hits and 4 pages per second?
Which is very funny: this is an article explaining how a web site survived the /. effect, thus trying to catch the /. readers back for a second round, and getting lots of advertising hits at the same time. If only that server could keep up. /. I saw a report about a 200Mhz (?) PC running Windows 95 and with about 30 hard disks, that also seemed to do very well under the /. effect.
Now, a while back on
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I never really thought that the problem lied with the server's hardware, but in the bandwidth to the host. Shouldn't an article be written about how to conserve bandwidth during a slashdot effect? Even older servers should be able to handle 100 requests per second. I think most FPS's are alot more taxing than that.
In 1994 websites were nothing more than text documents with perhaps a handful of small .gifs in them. They werent plastered with media-intensive-ads, java applets and shockwave whizbangers, background music, video clips streaming off the same server and blah blah blah innovation.
/. links to are personal sites run off of a DSL line. I think the effect has more to do with bandwidth than server load.
The web-design and server world seems to be focused on quantity, not quality.
And frankly, much of what
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Some static story pages? Who cares?
It all depends if you are actually doing something of interest.
Like the comments in Slashcode, most apps go from static, to dynamic, to static caching of dynamic pages.
At DTN we served up customized portal pages to people with commodity and equity quotes, news, graphs, etc. Since they didn't have any money we had to use a load balanced Pentium Pro and a Pentium II. The app had no problem serving the load, and it was fast.
Now that I work for companies that have money, our apps run really slow. Developers get expensive machines and don't know how to optimize any more.
As a bunch of people have pointed out, it is unlikely that the /. effect is a matter of "crashing" servers. It is much more likely that most of the "slashdotted" sites on the front page on a given day involve a server which is doing just fine and a bandwidth pipe which is seriously about to burst.
You can saturate most any small-business-affordable pipe with a Pentium classic machine as a Web server. Or to put it another way, there's no point sticking a dual-P4-Xeon Web server with 4GB memory and a RAID-5 on a DSL line.
The computer I'm using right now (a PIII system) could run Apache very nicely in the background and would likely survive quite a hitrate without too much trouble. But if even just a few thousand people were to hit it all at once, there would be a traffic jam, some people wouldn't get served, and the ISP would probably close me down, because I'm only sitting on a 256k pipe.
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I hate to do this, and get into some kind of "look at my l33t skills" type thing...but seriously, those numbers are just nothing to be impressed with. As several people have pointed out, usually the limitation on a well configured server is the bandwidth available. I have a buddy who runs a few adult sites, and I go ahead and keep his machines updated, optimized, etc, etc. On one web server alone, with simply rebuild Apache with a higher HSL and streamlining only essential services this *one* server is handling an average of 16,000,000 hits per day. (avg approx. 16,000,000 hits, 5,000,000 pageviews, 450,000 unique visitors per day). In fact, only last month did we set up a separate database server in anticipation of him getting even more traffic (I wanted to separate the web server from the db server esp. if we were gonna move to load balancing)...even still the cpu load was consistently low and the site was/is serving dynamically generated content (php) and is all driven by a mysql content management system. I have yet to even max out the usage of the server and do some ulimit type stuff or hard adjustments via kernel changes.... so what is the big deal about this article. I think it would be good to put up an article about how to optimize your web servers both in layout and actual configurations to allow for Slashdot levels of traffic. I doubt this will happen, just as the mirroring content on featured stories to help ease bandwidth or other similar suggestions. The saddest part is that once you spend the time to really optimize a machine or machines...it takes far less time to maintain them.