April 9, 2011
Cloud computing is now synonymous with Flexible Provisioning and Scale. Find out below if you are taking full advantage of cloud computing.
The As Is deployment – lowest adoption cost, reasonable benefits:
Move the server application “as is” to a cloud server. This is nothing but a co-located server, at Amazon for example. The provisioning and maintenance of the application is still a self driven task.
The win is in the dynamic on demand provisioning. Easy to compute the ROI here. Let us say that your application needs to be available all year round – but cater to seasonal demands. Say it costs $400 to host your application to cater to peak demand. You would end up paying 12*400 = $4800 per annum to keep your application up. Most of the time it would be under utilized. Cloud computing has made it really simple to change your compute capacity as easily as setting a reminder in your out look calender. With amazon or google, you could just log into the admin panel and say that you need additional resources only on certain dates. At the end of the month you get billed for the amount of resources you actually consume.
The Managed RDBMS deployment – reasonably low adoption cost, reasonable benefits:
A lot of work has to be done to ensure that the application is available. i.e. a replication strategy and policy to keep the database available. This is still a lot of effort and money. The alternative is a managed RDBMS, where the provider (amazon or google) manages the database. They worry about keeping the data safe from being lost. Much harder to do the ROI here – as the time spent in managing this would have to be offset against opportunity costs. Note that there would be some amount of code restructuring (not a lot) to get this going. An example of this is the Amazon MySQL RDS. At the time of writing, google is yet to announce the availability of their hosted sql service.
The Application Rewrite – highest adoption cost, highest benefits (arguably)
If your goal is to write an application which scales very well then you should consider a complete application rewrite to take advantage of the storage APIs. Hosted RDBMS is still a single machine (or a cluster) running a database server – with bottlenecks – be it memory, cpu, networ or disk.
Cloud computing offers storage APIs to access and manage data unlike traditional methods of file or rdbms storage. Because of the underlying architectural differences, cloud datastore offers better scalability - http://labs.google.com/papers/bigtable.html.
April 8, 2011
The app engine team in its RCA explanation stops at this point :
The Datastore relies on Bigtable to store data (read more about
Bigtable here: http://labs.google.com/papers/bigtable.html). One of
the components of the Bigtable is a repository for determining where a
specific entity is located in the distributed system. Due to
instability in the cluster, this component became overloaded.
Instability in the cluster? Sounds like a bug in the system which Google does not want to talk about in detail. But why go through this whole ritual of trying to be transparent with the community? Being an engineer, this is not an acceptable RCA. Who are they kidding? We don’t know whether the problem is really fixed or it is still lurking out there. Knowing a thing or two about clustering, instabilities of any kind are not that easy to fix. Let us wait and watch.
Still a fan of GAE.
January 9, 2010
Google App Engine provides you a ready to use environment to build and host web applications. The hosting environment is secure and made highly available by the google’s cloud computing infrastructure.
While GAE provides you such a strong platform to build and host web applications, it has it’s own limitations as well. While Google’s infrastructure gives you abundant computing power but not the case with storage which you would expect if you are developing web applications which require a large amount of flexible secondary storage as well, for that even the applications requiring moderate amount of secondary storage to store the files.
Coming to the actual point, GAE has a limitation of allowing applications to store not more than 10MB of a single large file on it’s server. This may not be a problem for some of the web applications. This is a serious issue for many web applications which assume sufficiently large underlying storage, given these days secondary storage is available in abundance at cheap rates. Some of the developers and users are shying away from using GAE as a platform for their web application development and hosting only because of this reason. And to make life hard google does not have a paid service either to work around this issue.
What are these web application developers supposed to do? Switch to something else which offers sufficient storage along with computing power. The other better options available are Amazon EC2 and VPS. Give me a break. Why do we want to run away from the problem? Well, look around. Amazing Amazon is there to help you out. We need to think creatively and be selective when making decisions about technology these days. There are a bunch of technologies lying around. It is just a matter of selecting and integrating the two technologies and using them to satisfy needs. I am not trying to promote any specific cloud here, but to highlight the fact that GAE and Amazon S3 work really well. And it turns out to be a cost effective solution.
GAE provides the development and hosting platform for you web applications at free of cost while Amazon S3 provides you reliable, powerful and abundant storage at cheaper rates. GAE and Amazon S3 together can do wonders.
Enough of theory, let me explain it to you with a practical example.
We, at BYGSoft, had a requirement to develop a web application for one of our clients. It was a simple web application which will work as a download portal for it’s customers. We chose GAE as a development and hosting platform for web application and Amazon S3 as the back end storage.
Read More : http://www.bygsoft.com