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Solutions to Ease the DDOS Trickle-Down Effect?

Posted by Cliff on from the snowballing-traffic dept.

dealsites asks: "Recently, The Electorial Vote website run by Andrew Tanenbaum was hit with a triple-threat. Not only was it Slashdotted, it was hit with a DDOS attack in conjunction with the busiest normal traffic day, due to the election. Netcraft has an article detailing the steps taken to mitigate the traffic. Andrew's host provider is also the provider of my site. I'm sure were are on separate servers, him a dedicated server and semi-dedicated hardware for myself, but I noticed dramatic slowdowns of my site during this triple-threat traffic onslaught to Andrew's site. Are there any techniques other than throwing more CPUs and bandwidth at the problem to remedy this type of situation? I'm sure I can't be the only one that has noticed this. Any comments on other similar stories?"

8 of 15 comments (clear)

  1. Nice. by Dibblah · · Score: 3, Funny

    "Not only was it Slashdotted"... Twice. You evil, evil submitter.

  2. Not to advertise by ebrandsberg · · Score: 4, Informative

    But the company I work for provides products that help in situations like this, although pre-planning for such events is critical for surges like this to be handled cleanly. For anybody interested, check out http://www.netscaler.com/ for information. Some key things to look for:

    1) That your upstream provider has sufficient capacity to handle large surges in traffic to one part of their infrastructure
    2) If you expect to receive a large surge, to overprovision your upstream links
    3) Make sure to have a front-end device that can determine "legitimate" traffic from bad traffic such as syn floods, and deal with the capacity of the upstream links.
    4) Make sure you have the ability to cache hot content in case you max out your servers if you need too. You don't need to regenerate a page of voting information with every request if it only changes ever few minutes, cache it to reduce the server load.

    In many cases, people fail to insure they have enough bandwidth on their upstream connections, and then put firewalls on the other side of the connection. Firewalls will tend to die under a heavy syn flood, and if they don't if you don't have enough capacity, it won't help anyway.

  3. Site is under attack currently... by stienman · · Score: 2, Informative

    From the main page of electoralvote2.com:

    All the servers appear to be under attack now, also DNS. I added another large multiprocessor but it doesn't seem to help much. I don't this is going to work. Sorry.

    The remainder have older messages on them - not sure how or if they are being automatically synced.

    Bummer, but kindof expected. Seems that he's using only one provider...

    -Adam

  4. coral by comwiz56 · · Score: 4, Insightful

    auto redirect all hits to a coral cache

    and maybe slashdot could post coralized links the in the articles

  5. File size by jm92956n · · Score: 5, Informative

    If you know you're about to get hit, minimize the graphics and streamline the code; this guy's got a page that's just over 30 kb (including graphics). Provided the page isn't generated dynamically, it shouldn't be too tough for a decent server to handle.

    Throw in some flash and a bunch of fancy images and you've got a recipe for disaster.

    --
    An effective signature identifies a particular user amongst a base of thousands.
    1. Re:File size by Kris_J · · Score: 3, Insightful

      That PNG map is two thirds larger than it needs to be. Less than a minute with pngout reduces it from 14,632 to 8,839. Also, it doesn't look like the page is being served gzipped. This can be done by creating a .gz copy and having the web server software hand out whatever the browser can handle, little or no cost to the CPU. All up, the site is probably serving 50% more traffic than it need serve.

  6. Re:Deliberate troll... by Morosoph · · Score: 2, Insightful
    Maybe Non-Partisan means just that. He also clearly links to a pro-Bush site. From this page:
    I am a Kerry supporter. I am open about that. Despite my political preference, I have bent over backwards to be scrupulously honest about all the numbers, and have carefully designed the main page to be strictly nonpartisan. Only the third row of menu items below the map contains material that could be considered pro-Kerry (e.g., jokes about George Bush). If you are a Kerry supporter, an independent, a moderate Republican who is fed up with the President's fiscal and other policies or even a conservative Republican who feels betrayed and who has a sense of humor, you will probably enjoy them. If you want an election site that has a pro-Bush bias from beginning to end, including all over the main page, try www.electionprojection.com.
    --
    Wikileaks, no DNS
  7. Re:Deliberate troll... by dubl-u · · Score: 3, Insightful

    It's just as well that his site is knocked off.

    Yeah, that democracy stuff lets the wrong people have a say. Thank goodness there are script kiddies to prevent that. We should get together and buy a gift for them. How about some nice brown shirts?

    I realize that he's got just as much of a right to say whatever he wants, but it troubles me that some people are looking to this as an authoritative source of information. IOW, he's biased.

    Having an opinion doesn't mean that he's biased. Some people can separate the two. And he pretty clearly has.

    He's honest about his opinions, makes clear where he gets his data, and has a simple formula that he used to do the totals and the map. Out of the history I have in my RSS reader, his tally had Bush leading 14 times, Kerry leading 13 times, and them tieing once. As far as I can tell it's an honest effort to present the poll results in a useful format. He even provides the data as a CSV, so you can run the numbers as you please.

    So unless you have some proof that he's fudging the numbers, maybe you can lay off your apparently biased accusations of bias?