The Slashdot Effect from the Other Side | Hacker News Reader

The Slashdot Effect from the Other Side

cmdrtaco.net

163 pointsCmdrTacoMalda41 comments

I'm amazed he didn't have any data prior to this.

We used to ask people all the time if the would send us their sanitized logs so we could see the "reddit effect", or at least give us the aggregate data.

I've noticed that it really depends on what subreddit your link gets featured in on Reddit.

I still get a lot of traffic from r/food, but it was relatively miniscule compared to the traffic I got from a post in r/reddit.com (which no longer has any incoming traffic).

I had some estimates, but this was the first time that I was ever 100% completely on the outside looking in.

You two should set up a website. Allow voting on comments, or something.. :)

Fair enough. :)

I should see if I can get one of my posts to the top of reddit. So far all my best submissions were on the reddit blog.

For a number of years, I worked for technology news sites. The Slashdot effect frequently brought sites down, particularly in the earlier years when /. seemed to have more influence (this was before HN, Stack Overflow, TC and a number of other blogs) and load-balancing, cache and other elements were not optimally configured on our end. Breaking news or particularly controversial topics could bring upwards of 50,000 uniques/hour. This was a big deal for us.

Global news sites can experience far bigger surges when a major story breaks. Around 10 years ago CNN started switching out its regular home page for a version that stripped out video and most images when major stories broke. Not sure if CDNs and better Internet video technologies have reduced the need for this ...

"Around 10 years ago"

or in other words after 9/11 melted servers everywhere.

Did you create an HN account and submit this so that you could measure the HN effect? :-)

I created the account yesterday simply to share the story that Slashdot actually picked up. Then I emailed info@ here to try to get 'CmdrTaco' back. It sucks that someone is squatting my nick here!

Sorry, was actually holding it for you since I saw you resign from slashdot. Email the address in the profile and I'll turn it over to you.

Honourable cyber squatting? What is the world coming to?

It'd be interesting to get an idea of how the "HN affect" compares to slashdot. Followup article by chance?

I'm not sure how it compares to slashdot, but I have had some of blogs on thingist at the top of HN, reddit/r/programming, getting tweeted by lots of my heros, on adafruit (which was really cool, since I really look up to Limor Fried, a lot).

That is one of the coolest feelings in the entire world for a little nerd like myself. Usually

    tail -f /var/log/apache2/access log

is running on one of my monitors all the time, so I can pretty much watch visitors as they come into the site (I don't even see the code, I just see blonde, brunette, redhead). When I've gotten that sort of traffic, I can't make sense anymore. It's the difference between taking a drink from a fountain, and sticking your face down a geyser.

Not only that, but to then watch your code stand up to the traffic is cool :).

Like a webdev version of your first kiss, I suppose :)

It's a bit surreal. I once posted a picture on my petty little website, and posted a single link somewhere. The link ended up on DrudgeReport.com. Soon couldn't even FTP the site for some vital maintenance[1]. Had to call the ISP:

"Hello, Foobar ISP, can I help you?"

"Hi, I'm the reason your servers are melting down right now."

"Ah. Let me connect you to the company president..."

Told him the detailed story, he got a kick out of it, and deleted the attracting file.

([1] - AP took issue with what I thought "fair use" of the Elian Gonzales pictures the day they were published. No argument; I didn't expect concocting them into an animated time-lapse sequence would get _that_ popular.)

Is anyone else surprised the EC2 Micro did so well?

If you read the EC2 forums[1] for any amount of time you get used to seeing post after post of "hung sites" running on the Micros when a constant level of demand is made on them (not the intended usage model[2])

Under load the Micros frequently go into a catatonic state with %st ('top') climbing to the moon as the VM environment provisions the brunt of the server's resources to the other VMs on the machine and starves out any hungry Micro instances (as designed).

I didn't think you could host anything on them with regularity. Maybe a swarm of them behind an ELB, not not a single one... anyone else had the same experience that Malda had?

[1] https://forums.aws.amazon.com/thread.jspa?threadID=58323

[2] http://docs.amazonwebservices.com/AWSEC2/latest/UserGuide/in...

Last time I tried the micro's they were mostly starving on I/O. Quite possibly his webserver wasn't doing much of that?

Also "tens of thousands" of requests is not really a big number anymore. Nginx will happily serve a couple thousand per second even from a micro (until it gets choked by the EC2 resource beancounting).

moe that's a good point, if he's got all the pages statically cached and all the graphical assets on S3, all nginx would need to do is serve back relatively small TXT files which even on the micro would be trivial.

On micros, if the load is CPU intensive, the vCPU gets throttled pretty quickly for sustained loads (say over 10 - 15 seconds) and your Steal Time CPU percentage goes up -the hypervisor will give someone else real CPU cycles before coming back to serve you. So, they are good for low traffic sites with bursty loads but not good for sustained traffic/loads.

Traffic on an EC2 micro instance for a website I run: http://i.imgur.com/bR6I8.png

That is a higher traffic site than I expected a Micro to be able to handle.

Are you hosting dynamic content (PHP, Java, etc.) or is everything really heavily cached in static files/varnish and hosted out by nginx quickly so as to avoid saturating CPU or I/O?

Static. On this site I host mostly huge-ass html files (about 1 MB per request) with apache 2 and mod_deflate :-)

There is also a wordpress site and another database-request-heavy site with 500 requests a day.

The problems I had was that the access.log and error.log quickly ate up the 5GB space of the micro instance :-) Causing mysql to stop operating and me to scratch my head for a few minutes.

5GB is not a lot .. you want ruby1.9 with the default setup? That will be 180MB, and so on :-)

I understand that Amazon's S3 CDN is pay for what you use. If anyone here has had a traffic spike using Amazon's CDN, what amount did you owe Mr. Bezos? I would hate to have to tell my wife that we are buying groceries with the credit card for a while because my little website was on slashdot.

You can use the APIs to spin up more instances when traffic goes up (and then close them down when you're not using them), but that doesn't happen automatically. Other than that, bandwidth costs are very high at Amazon compared most places, but it's still only $120/TB. https://aws.amazon.com/ec2/pricing/

The question was about S3, which can be used to host static content. S3 has the same data transfer prices as EC2, but you pay for storage and requests instead of keeping instances running.

https://aws.amazon.com/s3/pricing/

Is this math correct? 400k of images, 1 million requests

400 * 1 million / 1024 / 1024 = 381.5 GB

381.5 * .14 = $53.41

Use CloudFlare[0] with your site. They cache your static content for free and estimate a 60% bandwidth savings as a result. Apparently you can continue to S3 host your content and they'll cache that too.

Disclaimer: I haven't used them, but I've heard good things about the service.[1]

[0] https://www.cloudflare.com/

[1] http://news.ycombinator.com/item?id=2631019 http://news.ycombinator.com/item?id=2561341

Technically S3 is not Amazon's CDN (CloudFront is) it just behaves like one and a lot of people use it like one.

For a localized readership, it is fine since all the data will be coming out of a single regional location. If you have global readership and need locality, that is where CloudFront comes in handy with 20 POPs around the globe that data is distributed to.

Serving off of S3 is not that expensive, even if your site goes gangbusters.

Serving off of CloudFront can surprise you because of the sometimes unexpected number of origin pulls that can occur as your data is expired from the edge locations.

You are sharing cache space on each edge node with every other CloudFront user, if your content is red hot it stays in the cache, but if it is low-volume (which is a relative term to the other traffic coming out of the node) it gets expired much faster, sometimes hours so any future hits for it will pull (download) it again from S3 to CloudFront, then back out from CloudFront to the client.

The performance implications aren't horrific (they can be for video) but the cost can double what you are paying with enough origin pulls occuring requiring redownload over and over and over again for the same files from the edge locations.

I have seen this catch a handful of people offguard to the tune of $100s of dollars or thousands on the forums over the last few years because they didn't realize this could happen... they just looked at the bandwidth rates on the site, multiplied by their payload sizes and thought that was the fixed rate.

Welcome to Hacker News CmdrTaco, assuming it's you.

I'm pretty sure he used a different account to reply to the comments here on the story about him retiring, so it's probably not him.

Looking at the original thread ( https://news.ycombinator.com/item?id=2924731 ) I don't see anything like that. Can you help me understand what comment you're referring to?

He might be mixing him up with hemos, who did post in that thread (but is a different person from cmdrtaco).

I created this account recently. I never posted during the original story that got picked up here (although I did read the comments). And yes, it's me. But you have no proof of that fact.

I find it interesting how I'm now reading cmdrtaco.net more than I'm reading slashdot.

My ad blocking project was slashdotted years ago. I remember looking at the apache logs in analog and going "Holy shit." Not only was the traffic huge but it lasted a few days. I just assumed that it would die off at 5pm.

My cheap webhost managed to handle it pretty well. No issues. Then again it was static HTML.

I just read taco's site. He doesn't mention what CMS he is using, but its Wordpress. I wonder what cache plugin he's using. That's pretty important stuff, just as important as what instance of EC2 he is using.

W3 Total Cache, from his page source.

I got slashdotted today (albeit by Slashdot Japan), and hit by Hacker News yesterday.

I will put up some stats later, but HN brought in 10,000 hits, Slashdot brought in about 600 people. I think the English vs. Japanese thing scared away quite a few people (ironic considering the content of the article..)

(As an odd note, I did panic after hearing about Slashdot but not after seeing people from HN - go figure)

In some verticals Slashdot can still bring more traffic than other tech sites. It all depends on the topic, and how well the write up of the story is.

/. still relevant..!

It varies widely I imagine- you can see it on Slashdot very obviously: some stories get 1k comments, others get 50. There is a HUGE variance in interest on stories- and it's not always predictable. But when the planets align, I bet the traffic generated could easily be low 6 figures to a single site, and that would be over 3-6 hours.

"Used to" for him/Slashdot would have been a loooong time ago.

How does it compare to the HN effect? :)

I'll probably write about that on monday!

Reply on news.ycombinator.com