Cloud Hosting Mag » CDN

Akamai Announces Akamai Download Analytics [News]

admin — Wed, 24 Mar 2010 11:33:32 +0000

Akamai, the leading CDN vendor, just announced the introduction of the Akamai Download Analytics. Getting useful data on files served over CDN’s has long been a pain-point for CDN users. Akamai Download Analytics hopes to address this by providing the following types of analytics:

User engagement data such as download duration and completion rate.
User analysis by geography, network and connection speed
User behavior data, such as start, stop, pause, and cancel
Usage metrics, such as bytes delivered and bytes per download
Custom reporting, such as the ability to define data sets, reporting dimensions, and metrics.

What is Time to Live ( TTL ) ? [FAQ]

admin — Mon, 15 Mar 2010 06:09:00 +0000

Time to Live or TTL is the time a file is cached on at a CDN ‘edge’ location. Content Delivery Networks (CDNs) work by caching files at numerous world edge locations, when a file is requested for the first time from a CDN the CDN requests the file from the data center and it then caches it at that edge location. The cache at the edge location will be refreshed once the TTL expires. So if the TTL is set to 2 weeks then the files will be cached at the various edge locations for a 2 weeks.

Content Delivery Networks ( CDN ) Pricing Comparison

admin — Mon, 15 Mar 2010 04:32:31 +0000

Contend Delivery Networks (CDN s) pricing is typically broken into bandwidth tiers plus a charge separate storage charge. To simplify comparison I have used the base bandwidth and storage of each plan for the CDN’s which publish pricing, others such as Level3, Akamai, Edgecast etc usually have a high minimum charge and are not suitable for smaller content publishers.
For comparison purposes the base plan for each CDN has been chosen which for all providers offers at least 5TB of bandwidth out. Other charges such as transactions and bandwidth have been ignored for this comparison as these usually do not have a significant impact on the final cost.

CDN Pricing (March 2010)

	Storage (per GB)	Bandwidth Out (per GB)	Bandwidth Out > 50TB (per GB)
Amazon CloudFront	0.15	0.15	0.10
Rackspace CloudFiles	0.15	0.22	0.22
MaxCDN	0.995	0.10	0.075
SimpleCDN	*	0.03	0.02

*SimpleCDN does not have a separate storage charge, pricing is in plans for a set amount of storage and bandwidth and overages are not allowed (you are required to upgrade to the next plan). The base plan used for this pricing comparison has 2GB of storage and 5TB of bandwidth per month.

Observations:

RackSpace CloudFiles is by far the most expensive CDN, especially in a high bandwidth environment (although the storage is cheaper than MaxCDN) . Its integration with RackSpace Cloud Servers and Cloud Sites mean it will still be a decent choice for RackSpace users who don’t have high bandwidth requirements.
SimpleCDN is by far the cheapest CDN although the plan structure will make it much more expensive. You are required to select a set plan which a fixed monthly cost (eg $150 for 5TB bandwidth and 2GB storage), so if you only use 1TB of bandwidth this would work out at around $0.15 per GB. Similarly storage is a fixed amount and you are required to upgrade to a more expensive plan if your storage exceeds the plan amount. This is inflexible and means the actual cost per GB of storage and bandwidth will be much higher than the published amounts.
Amazon’s storage (ie Amazon Simple Storage Solution – S3) works out much cheaper than other providers for very large storage amounts (eg >500TB of storage is priced at $0.105 per GB). It should be noted that CloudFront is not as tightly integrated into its S3 storage as the other providers. The CloudFront CDN is essentially a blot-on service to the S3 storage service. This makes CloudFront a bit more complicated to use although there are several third-party integration tools.

Content Delivery Network ( CDN ) Tutorial

admin — Sun, 14 Mar 2010 16:40:30 +0000

So you’re convinced that a Content Delivery Network ( CDN ) would be a huge benefit to your site (if you’re still on the fence just read this first) and you are unsure of how to integrate it. How to integrate a CDN into your site depends very much on your needs.

The first thing you will need to establish is whether to use http progressive download or true streaming. If you are serving images via the CDN or providing downloads (zip files, exe files or media files for download) then http (or ‘progressive’) download is the mode most suitable, if your app streams audio or video to users then true streaming is optimal. Http download simply dumps the max output possible on the user requesting the file whereas true streaming sets up a two way communication between the requestor and the server which allows for optimizing the stream to fit the user’s bandwidth and provides more intelligent features such as seeking to a point in the file (these features do not need to be implemented by the developer they should be available out-of-the-box with most media players).

Amazon CloudFront

If you are using Amazon CloudFront then your starting point will be the Simple Storage Solution (S3) which is the static storage component of Amazon Web Services, to upload your files to S3 from your application you will need to use S3′s REST API although some CMS’s do have integrated S3 upload capabilities (see Using S3 in WordPress). Amazon doesn’t provide a GUI to upload files to so you will need to use a third party tool – Jungle Disk provides upload to S3 although it is more of a backup solution than a file manager, S3 Fox Firefox plugin as an efficient S3 uploading and file management tool, in addition CloudBerry FileExplorer is a full featured desktop app for managing S3 and CloudFront files.
Any file stored in S3 can be served from AWS’s CloudFront CDN. To use CloudFront you are required to sign up for it separately to S3 (you can sign up here) Files served by CloudFront must exist in S3 and when a file is requested from CloudFront, CloudFront initially requests the file from S3 and then caches it at one of its edge locations. Once you have an account at CloudFront, login to the AWS Management Console and navigate to the CloudFront tab. Under a single CloudFront account you can have various Distributions which are essential ‘buckets’ of storage which can have different attributes. Click the Create Distribution button which will open the setup dialog, then select either to use http download mode or true streaming, and associate the Distribution with an S3 bucket.

Once the Distribution is created, you will be given a unique domain which will look similar to dxabw2ae51eqo.cloudfront.net , to request your files from CloudFront instead of S3 simply replace your S3 domain (in the format bucket_name.s3.amazonaws.com) with your CloudFront domain on all your file URL’s – the file names will remain unchanged.

Other CDNs

There are several other popular CDN’s such as CloudFiles, MaxCDN, SimpleCDN. In essence they work in exactly the same way – you are required to use a custom API if you want to implement uploading to the CDN from your app or you can upload the files manually and then link to from your app. Most of these provide an online file explorer which allows you to upload and manage files although there is not the same number of third party file management tools as for S3/CloudFront.

If you are using WordPress you can use several plugins to facilitate file serving from a CDN , notably W3 Total Cache allows you to specific any CDN to serve files from. CDN Tools is a plugin dedicated to the CloudFiles CDN which provides very tight integration between the WordPress file upload and the CDN.

See our CDN Pricing Comparison for pricing details.

Using Amazon S3 and CloudFront on WordPress

admin — Sun, 07 Mar 2010 12:42:30 +0000

For the past six months I have used Amazon Simple Storage Solution (S3) to store all the newly uploaded images on my WordPress installations and it works like a snap. But why should you host all your images on S3 when your can simply upload them to your own hosting account? There are several reasons why S3 storage is a superior solution to using your own hosting :

Hosting images on a separate domain speeds up site load times as most browsers can only make two simultaneous requests to a domain. Thus if all your file are on a single domain the requests are queued and handled two at a time which slows the load time.
Moving hosts is easier if the file locations do not change (a major difficulty in changing hosts is downloading, then uploading all the images and finally changing all the references in your articles).
If the files are on S3 it is very easy to transfer them to Amazon’s CloudFront Content Delivery Network (CDN). CloudFront will give an additional performance boost for user’s who are located geographically far away from your server as CloudFront caches the files in 14 locations around the world.
If you are approaching your hosts storage limit then using S3 will probably be cheaper than purchasing additional storage space on your host.

The S3 for WordPress plugin modifies the standard WordPress image upload dialog to upload the images to your designated S3 bucket, from there uploading files to S3 is seemless as it is the standard file uploading process.
You will of course require an S3 account, and you should add a separate ‘bucket’ for file storage (buckets in AWS are similar to directories).

CloudFront in WordPress

Any file stored in S3 can be used with AWS’s CloudFront CDN. To use CloudFront you are required to sign up for it separately to S3 (you can sign up here) Files served by CloudFront must exist in S3 and when a file is requested from CloudFront, CloudFront initially requests the file from S3 and then caches it at one of its edge locations.

Once you have an account at CloudFront, login to the AWS Management Console and navigate to the CloudFront tab. Under a single CloudFront account you can have various Distributions which are essential ‘buckets’ of storage which can have different attributes. Click the Create Distribution button which will open the setup dialog, where you choose whether to use Download (for images) or Steaming (for video) and associate the Distribution with an S3 bucket. Once the Distribution is created, you will be given a unique domains which will look like dxabw2ae51eqo.cloudfront.net , to request your files from CloudFront simply replace your S3 domain (in the format bucket_name.s3.amazonaws.com) with your CloudFront domain on all your file URL’s – the file names will remain unchanged. Unfortunately the S3 plugin in WordPress only works with S3 and you must manually change the file URL’s after uploading although a global find/replace plugin can be used for this.