Recently I’ve become more interested in the “Rackspace Cloud” as a viable solution for our clients needs.  Traditionally we have maintained dedicated servers w/ traditional Rackspace and hosted our clients sites / applications on there.   I have had no problems, so I have been hesitant to even take a look at other solutions.  Recently, however, as we’ve begun doing more Django applications in addition to our traditional work load of ASP.NET & PHP sites, I was turned onto Sicehost.  They were a perfect fit.  Then, low and behold, Rackspace bought Slicehost!   This seems to have evolved into what is now the Rackspace cloud.   So, naturally, my curiosity was peaked.  This was further spurred along by a recent friendfeed conversation.

I began to ask myself, could we realistically move away from traditional dedicated servers to virtualized servers and exist entirely in what is known as “the cloud”, while maintaining the same level of dependability that our clients have come to rely upon?  If we could then certainly the sheer scalability potential and flexibility would be worth it.   So, I began to take a closer look.

First, it is helpful to point out the three services that comprise the Rackspace Cloud aka Mosso:

Cloud Servers

This essentially seems to be the Mosso branding of what Slicehost offers.   The main difference being the Mosso service is a more pure pay per use model.  In other words you pay for the instances hourly.  You pay for your bandwidth separately.  Whereas with Slicehost it is a bundled offering w/ monthly charges for the servers and a set bandwidth that comes w/ the monthly fee.  Only Linux flavors offered.

Cloud Sites

This service is sort of like merging a type of traditional hosting company w/ cloud computing.  It promises a hybrid structure being able to deliver ASP.NET side by side w/ PHP (as an example).  Given that the Cloud Servers only offers Linux flavors, this would have to be capable of hosting our ASP.NET sites.

Update: I was recently asked if you could use Cloud Sites with Django.  From what I’ve read, you cannot because you don’t have access to mod_python – the python support is just CGI scripts.  For more information check out this post:

The perl and python support is just generic CGI script support. So there’s no support for mod_python, and therefore you can’t run Django.

Cloud Files

This is essentially the LimeLight CDN offered in an on-demand fashion coupled w/ the Cloud Sites / Servers offering.  In other words, if you have media files that you want to push to edge servers for quicker loading by the end user, this can simply be “enabled” to provide that on a simple per-use charge.

So, given the above services, several questions popped up.  Today I was able to chat w/ one of the support representatives and here are the answers:

Is there external access directly to the SQL Server 2008 database?

Yes.  Given the IP address of the SQL server you can access the database directly via SQL Management Studio.  Or, in our case, we have a scheduled process that runs against a SQL Server database.  This could run on a dedicated server still and use the SQL Server 2008 instance while the web app runs on the Cloud Sites.

What type, if any, firewall is available ?

With Cloud Sites access is limited to HTTP and FTP(S).  With the Cloud Servers only software firewalls (IPCHAINS).  No hardware firewalls are offered.

When signing up for the backup service, is the database also backed up?

I forgot to ask how this is handled w/ the SQL Server 2008 – I’m sure there are backups, but can a single DB be restored if say there is data corruption for some reason?  Unsure, I will ask and update this post.

With MySQL on the Cloud Servers, only file system backups take place.  So, if you want to backup MYSQL in any other way that simply having the DB files backed up you’d have to put in a cron job to do MYSQL dumps so those individual DB files could be backed up from the file system. With Rackspace traditional dedicated servers there is a MySQL agent that essentially does this for you.

With the “hybrid” system can I use a .htaccess w/ mod_rewrite commands w/ an ASP.NET web app?

Here I didn’t quite understand how this “hybrid” system worked.  After discussing w/ the support representative what happens is you still chose either Linux / Apache or Windows / IIS to host your web files.  The difference is that Windows / IIS also has PHP / Python enabled so you can also use those tools in addition to ASP.NET.  The Linux flavor doesn’t support ASP.NET.  As such if you want to run ASP.NET and PHP side by side, you have to pick the Windows / IIS flavor for that domain and then you can use PHP as well.  But, you wouldn’t have access to .htaccess for things like mod_rewrite which are available in the Linux / Apache world.

This ended up being a deal breaker for me as we use the Helicon Tech ISAPI Rewrite module to give our Windows / IIS based sites mod_rewrite capabilities.  We use this quite extensively and simply must have the ability to put mod_rewrite rules in the .htaccess files for our ASP.NET sites too.  If this was available, I think we could make it work and switch completely to the cloud.  Until it is, we will need to maintain our dedicated server for our ASP.NET sites.

Incidentally, if you are wondering why Amazon EC2 was not mentioned here, it is primarily because the Amazon service is ephermal which means that the instances can pop up and down.  This always seemed to be a challenge when assessing it against our client needs.  There is a good comparison between Amazon EC2 and Mosso Cloud Servers on the Mosso site.

Conclusion, we are going to start using the cloud for our Linux needs, but we will keep w/ dedicated servers for our Windows ASP.NET needs, for now.