CDN Transfer Layer

The CDN HTTP Interface

There are three different types of requests

Name Lookups

A name lookup is an HTTP HEAD request that, given a named file, will return metadata. Example:

curl -v --head http://cdn.sirikata.com/dns/global/jkusnerz/Boulder_Spire_01.mesh

> HEAD /dns/global/jkusnerz/Boulder_Spire_01.mesh HTTP/1.1
> User-Agent: curl/7.19.7 (x86_64-pc-linux-gnu) libcurl/7.19.7 OpenSSL/0.9.8k zlib/1.2.3.3 libidn/1.15
> Host: cdn.sirikata.com
> Accept: */*

HTTP/1.1 200 OK
Date: Fri, 18 Jun 2010 18:34:25 GMT
Server: Apache/2.2.3 (CentOS)
X-Powered-By: PHP/5.1.6
Accept-Ranges: bytes
Hash: ddde4f8bed9a8bc97d8cbd4137c63efd5e625fabbbe695bc26756a3f5f430aa4
File-Size: 11650
Content-Type: text/html; charset=UTF-8

File Metadata

You can also do an HTTP HEAD request to get metadata for a hash directly. Example:

curl -v --head http://cdn.sirikata.com/files/global/ddde4f8bed9a8bc97d8cbd4137c63efd5e625fabbbe695bc26756a3f5f430aa4

> HEAD /files/global/ddde4f8bed9a8bc97d8cbd4137c63efd5e625fabbbe695bc26756a3f5f430aa4 HTTP/1.1
> User-Agent: curl/7.19.7 (x86_64-pc-linux-gnu) libcurl/7.19.7 OpenSSL/0.9.8k zlib/1.2.3.3 libidn/1.15
> Host: cdn.sirikata.com
> Accept: */*

HTTP/1.1 200 OK
Date: Fri, 18 Jun 2010 18:11:59 GMT
Server: Apache/2.2.3 (CentOS)
X-Powered-By: PHP/5.1.6
Accept-Ranges: bytes
Content-Length: 11650
Content-Type: text/html; charset=UTF-8

File Download

Once the hash is known, you can download the file, and range requests are supported. Example:

curl -v --range 500-999 http://cdn.sirikata.com/files/global/ddde4f8bed9a8bc97d8cbd4137c63efd5e625fabbbe695bc26756a3f5f430aa4

> GET /files/global/ddde4f8bed9a8bc97d8cbd4137c63efd5e625fabbbe695bc26756a3f5f430aa4 HTTP/1.1
> Range: bytes=500-999
> User-Agent: curl/7.19.7 (x86_64-pc-linux-gnu) libcurl/7.19.7 OpenSSL/0.9.8k zlib/1.2.3.3 libidn/1.15
> Host: cdn.sirikata.com
> Accept: */*

HTTP/1.1 200 OK
Date: Fri, 18 Jun 2010 18:16:36 GMT
Server: Apache/2.2.3 (CentOS)
X-Powered-By: PHP/5.1.6
Accept-Ranges: bytes
Content-Length: 500
Content-Range: bytes 500-999/11650
Content-Type: text/html; charset=UTF-8

<500 bytes of binary data>