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Cachefly Content Delivery Network

by | Nov 2, 2006 | Usefull Things

Further to my previous post about webservers for data delivery I’ve been investigating some content delivery networks.
One that’s been getting a bit of bloggers love recently is Cachefly, on paper and on their pretty flash movies it seems pretty awesome. However when it comes time to deliver it falls pretty short.
From their site a few bits from their blurbs:

While traditional (or ‘first-generation’) CDN’s have used ‘DNS tricks’ to circumvent BGP (the internet’s core protocol), BestHop™ instead harnesses the power of BGP to determine how content can be delivered in the most efficient manner over CacheFly’s global CDN footprint. BestHop™ uses Anycast to instruct carriers routers to make connections to the best available point-of-presence for the end user. By combining anycast with our unprecidented international footprint, CacheFly has built the next-generation in Content Delivery Network.

So by using anycast they route you to a static ip – always the same one – and your ISPs routing tables figure out the nearest POP where your files live, this sounds great I had some doubts about Anycast but I’ve been informed that it does in fact work well even for TCP traffic.
Their network seems pretty extensive at the moment, they have a link on their site called “Out Network” that opens a popup, this shows an impressive world view of servers in San Jose, Phoenix, Chicago, Toronto, Ashburn, London, Amsterdam, Stockholm and finally Tokyo. These locations are a good footprint for my needs.
Some more blurps from their site:

Speed counts on the web, and by using CacheFly for your website you can deliver your website up to 10x faster than traditional hosting.

CacheFly makes it faster:

  • CacheFly’s BestHop™ traffic management system delivers your content at blazing speeds by delivering your content from the ‘edge’ of the internet, placing it closer to your visitors.
  • Your content is always available. Guaranteed. So there is no need to worry about losing customers because of an ineffective server or network issues.
  • CacheFly provides you with instant scalability – Our technology means you’re website’s effectiveness will not be impaired by increased traffic. *Embrace* flash crowds. They mean more $$ now, not more headaches.

The load-time of your website affects your bottom line, period.

This sounds great, so I want to host my site furniture on it, buttons, logos and also user profile photos etc. I want the furnishings to load as fast as possible so that there are no perceived delay in the page drawing due to photos loading slowly one by one, and this seems to match my needs perfectly.
Finally some other claims from their site:

  • No changes to your existing hosting solution
  • Easy to implement, be live less than 10 minutes

So what’s the problem then? I signed up for their biggest account since I have about 1GB of jpg’s to host, the account lists 24 hour support, SCP, SFTP and rsync uploads as features along with some other stuff.
Once I opened the account and logged into the control panel I was immediately presented with only FTP upload details, no rsync or ssh based system. Turns out for this you have to open a support ticket which the auto reply claims will be actioned within a day, thats great, 10 minutes indeed.
As for delivery to nearest to your clients, well thats just bullshit to say the least, the way they do it is by hosting all your files in the states by default. If a file gets a lot of hits from a specific region they’ll then wait for some threshold to be reached then they’ll propagate your files internationally, in the words of their support people:

“in order for files to cached internationally, they need to be considered ‘hot’; which will take more than several requests”

I’ve now hit a specific file over 150 times from the UK and it is still being served from the states. So how do they serve it from a specific location given its anycast? Well I hit a webserver in the netherlands, this server then responds with a 302 and redirects me to another server – a non Anycast IP – in the states. So in effect every hit I take on my servers gets translated into 2 hits until they decide a file has hit some magic threshold, and its a varying threshold since a large file (512Kb) hit it early on after only 20 or so hits, a much smaller test file is still being served from the states after 300 UK based hits.
As for their network map showing servers in the UK? Not true at all. From their sales people:

Also, you should note that we are turning up our London POP next week, this will significantly increase the already superb performance of our product.

And another response after I queried some more:

We have routers in london now, however, they deliver traffic to our amsterdam location. Next week we’ll be adding delivery infrastructure, as well as deploying our 10G port to the LINX peering fabric.

So not even close to as advertised, I’ve had hits to files from South Africa, China, Korea, UK, US and AU and only 5 out of 351 were served from Amsterdam, UK traffic though accounted for 337 of the 351 hits.
Cachefly looks good on paper, this is only day 2 of my trial with them and even if they get my rsync access sorted out I can’t see how I can possibly go to phase 2 – actually sending traffic their way – if they can’t get my files actually served globally. I’ve asked them about this and am waiting on a response, it might still turn around and be a winner for now though I think Cachefly is ok for a reasonably popular podcast or a big RSS feed, but not for serving 6 million files per day as quick as possible which is what I need it for.
UPDATE: After waiting 2.5 days for their support to even respond to my request to enable rsync, I’m now closing my account. My recommendation is to avoid Cachefly as far as possible.

Webserver Performance

by | Oct 31, 2006 | Usefull Things

I look after a site that serves up a lot of static content, early on already I ran into issues with Apache coping on one machine, also my bandwidth at my main site is pretty expensive so I started farming off my static content to a number of machines hosted at other ISPs, typically paying around 100 pounds per machine per month, as long as I push out less than around 100Gb/month it’s a pretty good deal.
The only problem I have is I get tons of SYN_RECV connections on each of my machines, around 300 of them at any given time. Typically these indicate a lot of connections waiting to be served but the servers handle new requests immediately, there are no time spent waiting for IO on the servers, in fact the CPU’s are 98% idle always.
In an effort to try and resolve this (after much tuning of server sysctl’s) I asked Jaco if he’s seen it before and he suggested giving Lighttpd a try.
I installed it on one of my 3 static servers and ran it for a few days now and the results are encouraging. I still have 300 SYN_RECV’s but the machine is performing much faster than its siblings. On average before Lighttpd I was getting 30 requests/sec out of each of my machines now this one is doing around 50/sec, it is also pushing out about 30Kb/sec more than the other two. Comparing the Lighttpd machine to 2 apache machines on a graph shows it consistently out performs the others by about 20%.

Uptime 4 days 21 hours 19 min 20 s
Requests 18 Mreq
Traffic 20.77 Gbyte
Requests 105 req/s
Traffic 89.99 kbyte/s


There has been some discussion about Lighttpd and Apache benchmarks, one Apache user has written a debunk of the benchmarks. This is linked too from the Lighttpd home page so might be worth investigating some more, I’ve done a lot of the typical things that Apache people recommend but they didn’t help much. I think I’ll try and tune my one Apache server to hit the same performance as the Lighttpd and see if it’s possible, for now though I’m quite happy with the results of a quick 30 minutes spent upgrading to Lighttpd.

moo.com MiniCards

by | Oct 12, 2006 | Photography

A few weeks ago moo.com launched a very nice service, they take your flickr photos and make small business cards using those photos.
They did a promotion where they gave batches of 10 away I got some of those as soon as they came out and have since bought 100. At US$19.99 it’s a steal – the equivalent of about GBP10.


The experience is overall great, the cropping doesn’t always come out exactly as expected I have 2 images that I literally just have to through away since they are spoilt but I put about 30 images in so that only really come to about 6 cards. My suggestion is just don’t crop with stuff too close on the sides, otherwise I can really recommend it if you want something different from the usual.

First eBay experience

by | Sep 27, 2006 | Photography, Usefull Things

I’ve always been a bit wary of buying stuff off eBay, something about it just always put me off. My recent acquisition of a old camera though is forcing me to give it a go.
I wanted a few things for the camera, a few more lenses I find 50mm a bit claustrophobic, it needs a leather case and some other bits. So I’ve been looking at eBay again. This past weekend I did my first purchase of a Schneider-Kreuznach Retina Tele-Xenar 135mm F4 Telephoto Compur Lens for my Retina IV camera, the item was a Buy Now and I was happy with the price so I got it.
The lens arrived this morning and is as good as new I’m very impressed with it, here is a shot of my camera with the lens fitted. It came in its original protective case and everything, not bad for GBP24!


I’ve also bought another Retina camera, this one is a Retina S, very similar to the IV but it includes 35mm and 85mm lenses, bags, kit bag and all the goodies even some thirdparty book on the Retina cameras. Still waiting for this one to arrive though.
The second auction wasn’t a Buy Now so I had to way up if I wanted to actually try and bid on it or not, in the end I decided to go with one of the Sniper services. I searched around, there are tons out there with payment options going from monthly, yearly, per item etc it was hard to choose which one. I eventually came across Gixen, it’s a free Sniper run by someone who is passionate about doing so and I felt happy to use his service rather than some company I guess it’s years of using Open Source. Anyway in the end I got the item after the sniper did it’s bid, now I am just waiting for the knock on the door.

Domain Name Suggestions

by | Sep 26, 2006 | Usefull Things

Recently I had to buy up some domains for my employer – iTouch – so I typed into a domain registrar the word itouch to see what it came up with, what was available etc.
It also showed me a bunch of suggestions of other similar domain names:


It’s wonderful, IsItWorthTheHurt, ItWillHurt, ItHurt these are great and a lot of ex-itouch people will want to rush out and buy some of these I am sure, but the best of the lot has to be WhyDoesItHurtWhenIPee, priceless.