Web Hosting Talk : Web Hosting Main Forums : Colocation and Data Centers : CDN or GeoCluster for own purpose

[rustelekom]

Hi,

Interesting, for realize very begin level and simple CDN (not for competition with Akamai just for own purpose) or GeoCluster what we will need? I think we need own AS, at least two B/W provider for each point where we need make cluster (for example one cluster in Europe, another in US and one in the somewhere in Asia) and routers and load balancers on each of above point? Own AS i think required to make changes in routing if any of cluster or one of the server in cluster will down (failover feature). Am i right? What we need as minimum to make it work if we need exclude simple point of failures? One or two Cisco routers, one or two Coyotte Point system and lot of servers ?

[hhw]

It depends on how you want to do it.

BGP Anycasting is definitely superior to using GeoDNS, and for that you would need your own AS and a block of IP's /24 or larger. One bandwidth provider per location would be fine and would be much easier to setup.

Multiple providers of course gives you more redundancy, but isn't needed to make this work. Also, if you only have one provider at each location, you can just have them advertise a single default route to you, instead of having to crunch a full global routing table.

Locally at each location, you could go with redundant load balancers, or just run your servers in a VRRP (or e.g. HSRP, CARP) configuration. Load balancers are probably easier to setup, but you can achieve faster failover with VRRP.

You also need to determine whether you want to distribute your content using a pull (reverse proxy) or push (data replication) model.

If you don't have in-house expertise though, I would recommend finding a provider who does, as a good solid CDN definitely isn't easy. Is there any particular reason you need to roll out your own CDN, instead of using a CDN provider?

[Jdubz31]

Unless you have an absurd amount of traffic that you need to push, a fairly hefty startup allowance, along with several experts, I'd outsource it.

Voxel.net has an excellent CDN product that you could likely resell. I'd start there if I were you.

[KDAWebServices]

You need a real solid understanding of BGP and how various providers run their networks with anycasting - ideally you need to use the same 2 or 3 providers in each location, else you could end up with all sorts of v. funky routing. If you don't know what I mean by that, then you're not ready to be doing it

[rustelekom]

Thank for all!
Yes, knowledge required definitely. And i agrees that for beginner best way will be outsourcing and we will probably begin with it.

[cristibighea]

Just remember that unless you need to get your data to a global audience, and get a lot of data to them too, the costs will be pretty high even on a CDN, so you might have to commit to a rather high amount of bandwidth per month to get a good price.

[apollo]

Doing it right the first time takes a lot of skill and costs are high. I would suggest reading TCP anycast problems as well.

Remember that for failover, you should use your own routers (any top brand or quagga if you prefer Linux/*BSD) and scripts etc that would withdraw the route. Somewhat complex set-up that should work perfectly.

[dkitchen]

This is something I've been doing a lot of research on as we plan to build a CDN product to meet some clients needs in the near future.

You obviously have two options for your traffic distribution. You can do it DNS based which is pretty accurate, although you will run into problems where IP space is registered to an organisation in one country however it's physically located in another; or where an ISP's DNS servers are in one location but the end user is in another, etc.

The other option is of course anycasting, but as Karl said it takes a great deal of BGP knowledge to make it work properly. You need to ensure your network configuration at each site is almost identical or your users, on occasion, are going to be routed to the most connectable location rather than the closest (one of the traits of BGP). In addition you have the issue of route overlap too which causes issue with TCP, good planning/design should avoid this however.

You could potentially use the two in conjunction with each other but I can't see any real benefit to that without introducing masses of complications.

Finally you will need a number of servers to remotely monitor your clusters and make DNS/route changes where necessary.

CDN's are expensive solutions whether you run them in-house or build your own. I couldn't tell you which would be more cost effective, you'll just have to weight up the costs factoring in the equipment and expertise you're going to need...

Dan

[cacheflymatt]

Generally you wont get great economies of scale (relative to buying it) for rolling your own CDN until a few hundred mb/s, however obviously it offers you much greater flexibility for you since you'll be controlling your own servers.

One other option - limelight offers a 'managed cdn' type service: http://www.limelightnetworks.com/man...astructure.htm in which they handle the traffic distribution and you manage the content serving.

As far as TCP anycast goes, you shouldn't have any issues at all if you're just starting out with a US/Europe config.

Here's some operational experience with it from ourselves and bitgravity:

http://www.nanog.org/mtg-0606/pdf/matt.levine.pdf


Matt