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Why does digg need so many servers?
- jgrahamc 16y agoNon-linearity.
- nkassis 16y agoEven then, 500 servers? That's an incredible amount. EDIT: Then again Facebook is using 60000 servers at the moment.
- ceejayoz 16y agoFacebook has a lot more than 100 times digg's registered users, though.
- dasil003 16y agoNot to mention a basically non-existent cachability profile, and an order of magnitude more functionality.
- nkassis 16y agoI'm assuming you mean Facebook has more functionality and no cachebility. That might be true but I wonder how expensive getting a Digg discussion(with 100-200 posts) page compared to say a 5 answer SO question or even just a simple Facebook profile.
- ceejayoz 16y agoAs I understand it, a Facebook profile is anything but simple.
- tibbon 16y agoJust as perplexing, why do they need ~68 employees (http://about.digg.com/team http://about.digg.com/team). My counting may be off by 1-2, but last I checked Reddit is coming up on them traffic-wise (http://siteanalytics.compete.com/reddit.com+digg.com/ http://siteanalytics.compete.com/reddit.com+digg.com/), and only has 7 employees? And I'm pretty sure Reddit doesn't have 500 servers either, although I could be wrong. Both sites offer very similar functionality. While past its peak, Slashdot only has 18 servers. (http://slashdot.org/faq/tech.shtml#te050 http://slashdot.org/faq/tech.shtml#te050)
- noodle 16y agoreddit uses something like 250-300 EC2 nodes.
- tibbon 16y agoUnless they are using the really big instances though, I find that EC2 nodes are generally lower in power compared to what most people are using for their servers. I remember not too long ago before they moved to EC2 everything fit in just a few racks. Of course, their traffic has expanded significantly recently.
- ergo98 16y agoEC2 nodes are terribly underpowered, particularly in the I/O realm (the biggest weakness of virtually every site) where a standard desktop absolutely annihilates the I/O performance of an S3 connection (where you have to perform software RAID to get anywhere near the performance of a single magnetic low-end SATA drive, which is absolutely terrible). A lot of the "web scale" noise has come from dealing with these gerbil sized instances.
- deleted 16y ago[deleted]
- Lewisham 16y agoMy understanding (which is, to say, belief built up over watching the companies from outside) is that Reddit is currently running what could best be described as a skeleton crew: Conde Nast won't fund them, so they're just trying to keep the ship afloat and don't have time for anything else. Digg has scaled to the size of a company that, for a couple of years now, has considered itself just on the tipping point of "something big happening." As in there being a sea change in the way everyone consumes their news, and Digg is at the center. You'll need lots of employees when that happens, right? I think Digg has partly grown fat due to non-existent leadership; the struggle between Jay Adelson and Kevin Rose was been well-documented, and having your two lead guys check out for at least a year is not a good way to run a business. A lot of the people there are "sales", which I guess helps Digg stay profitable, but I don't really think you need as many as they have. Five community managers on a community that is supposed to manage itself is also excessive. I expect the truth of the matter lies somewhere in the middle of Reddit and Digg. More than Reddit so you're not stagnant, less than Digg so you're not fat.
- jswinghammer 16y agoMy last job served around 30-40 million pages a month on 4 servers that used ASP.Net and SQL Server 2000. The only server whose CPU utilization was over 20% was the database server. I'm not sure the CPU utilization on the web servers ever went above 10%. A friend of mine's company has a tough time keeping up with 500,000 page views a month using more equipment. They're using PHP and MySQL.
- thirsteh 16y agoSo, do you get free coffee in the cantina at Microsoft?
- jswinghammer 16y agoI'm not sure what you are suggesting? Free coffee would be enough to get me to say something nice about Microsoft products? I work at Microsoft?
- alecco 16y agoAnd Michael Schumacher with a compact can beat you on a sports car.
- hkuo 16y agoNot in a drag race where he's driving a Yugo and you're driving a Ford GT. Unless you crash of course.
- rythie 16y agoApple and Oranges comparison really. - What do the sites do? - How optimised are they? - How much static/cachable content is there? Really there is too little data for this comparison.
- jswinghammer 16y agoBoth are simple sites by any definition. The database queries for almost all the pages views are clustered index seeks (on SQL server) and in MySQL they are mostly looking up on the primary keys for the tables used (these are MyISAM tables so no clustered indexes here). Both are equally unoptimized outside of the database queries which I believe are fairly well optimized. No real cacheble content on either outside of the usual suspects (JS, CSS, some images)
- robryan 16y agoDepends on the servers to, I'm sure it would take more than 5 servers that Google run to run SO.
- marcrosoft 16y agoOne thing is for sure, Spolsky sure knows how to scale his ego.
- jswinghammer 16y agoI'm not sure what that's supposed to mean.
- jbail 16y agoMaybe Digg uses small servers whereas StackOverflow uses big servers?
- fauigerzigerk 16y agoUsing big servers would be what Microsoft's licensing model makes you want to do.
- mrtron 16y agoWhy does it take 20 feet of land to grow a gallon of orange juice and 200 feet of land to grow a gallon of apple juice?
- njharman 16y agoA site that posts links, has voting and comments vs a site that posts questions has voting and comments is hardly apples vs oranges.
- deleted 16y ago[deleted]
- Goladus 16y agoWhere does the "500 servers" number come from? Are they compute nodes? Are they webservers(5)? Webservers and appservers(10)? Web, app, database(12)? Web, app, database, back-end processing(15)? How much redundancy is built in(30)? Staging environments(60)? Development environments(120)? Standard IT infrastructure like DNS and email(125)? "We run over 500 servers" sounds a lot like "we have 500 servers in our datacenters" not "it takes 500 servers to handle 200MM page views."
- jasonlotito 16y agoPretty sure those numbers discount serving up Digg information out to every blog that includes a Digg button as well. Pretty sure if SO adding something like it, they'd be running on more than 5 servers.
- sfrench 16y agoI used to work at digg as a engineer. I won't say your distribution numbers are correct, but you've got the gist. There are multiple environments, reserved capacity, research and testing machines, etc.
- ojbyrne 16y agoWhere does the "500" come from?
- sfrench 16y agoKevin mentioned it somewhere a few weeks ago. I forget where though.
- eogas 16y agoDigg is using Eee PCs as servers?
- benologist 16y agoDigg must be pluggr's biggest customer... http://pluggr.info/ http://pluggr.info/
- schulz 16y agoThe difference is that digg has network information (IE: Followers). Stack overflow doesn't. Think through the ramifications of each of these page flows: 1. Give me this question and everybody who commented on it. 2. Give me every post that this user is following has made over the last n days. That's why.
- nkassis 16y agoI think this is exactly it. You can't compare a comment thread on Digg to a Question on SO.
- mhill 16y agoThat would increase the load on the database. Why does that increase the load on the webservers?
- schulz 16y agoIt depends how you approach the problem. I'm guessing here, from my own experience implementing social graph features, but here goes: There are a couple of ways you can go about this, the first is the database: Join the network of people against the land of content and bring it back. This doesn't work (as an aside this is what people mean when they say web scale, it has nothing to do with web traffic, it's social graphs) your database will cry. All though not at first, in development it works fine, and you feel fine, and for a while you're ok, but you start growing.... Another way you can go about it is by denormalizing. In this world you store a pointer to each content item for each user. So anytime I do something all the people [following|watch|connected|friended] to me get a record indicating I did this. This works, but now you have lots of data (lots and lots of data!) spread all crazy around. You need some kind of system to push that data out to everybody. It's those last two that drive up your hardware usage, it's not necessarily web boxes, but it's boxes in the background broadcasting the events out to the world, and the datastores to hold it all. Depending on how your web code works you could also have a lot of overhead on the webservers putting all that stuff together. My experience here comes from building the social features into toolbox.com. A good example is this page http://it.toolbox.com/people/george_krautzel/posts-connections http://it.toolbox.com/people/george_krautzel/posts-connectio... That's all the posts from users connected to our CEO (all 750k of them). Getting that to return in near real time is super fun (and you can probably tell that I went down the DB join path before it all fell apart).
- mhill 16y ago[Sunglasses On] Sounds like the .Net stack performs much better than the LAMP stack.
- mhill 16y agoI thought people on HN are more open to technology discussion. It seems people can't handle their bubble being pierced when presented with facts. It would be more interesting you have facts to refute my statement than downvotes.
- fauigerzigerk 16y agoWhat's the cost per page view in each case?
- nozepas 16y agobad server administrators? no optimization? no cache? static content served from apache servers instead of, for example lighttpd? there could be many reasons
- wanderr 16y agoI mentioned this to Spolsky already but depending how you want to count servers (web servers or all front facing servers or all servers in your infrastructure?), we have 10-20 servers servicing 350 million page views per month. That is of course not counting all the ajax requests that we also service, which don't count as page views. So we service 17-35 million page views per server, compared to StackExchange's 12 million page views per server. We use PHP and Apache, so the gloating about ASP being way more efficient than PHP seems to be unfounded.