Original URL: http://www.theregister.co.uk/2011/06/29/hybrid_cloud/
When hybrid clouds are a mixed blessing
Aiming for the best of both worlds
Cloud computing is a perfect fit for some, while others prefer the flexibility, security and certainty of in-house applications.
Between the two are those looking to embrace the cloud without throwing their IT investments out with the bath water, and for them the hybrid cloud seems to be the way forward.
What is involved and can the hybrid cloud really be made to work?
The concept is simple: keep some in-house servers and applications while moving others to the cloud.
One way of doing this is to rent virtual server space and host your applications there. Another is to switch to applications such as salesforce.com  and Google Apps , with providers that manage both the servers and applications for you.
Either way, deciding which applications or bits of applications to keep in-house and which to put out to the cloud is far from simple. Nor is it easy to gauge the success or otherwise of a pilot scheme, particularly if you start to factor in concerns about data sovereignty.
Some applications cry out to be in the cloud. Remote hosting of email and collaboration servers, for example, is commonplace and no more difficult or less secure than running Exchange, say, on your own servers.
Test the water
Moreover, those who don’t want hassle can simply rent mailboxes from an ever-growing army of providers.
The ready availability of established and well supported communication protocols makes it easy to connect messaging and collaboration clients, such as Outlook or even the latest mobile devices, with host servers.
And because communication is largely asynchronous, the servers can be on-premise, hosted or mixed together for a truly hybrid solution. Moreover it is easy enough to run a pilot and gauge performance, both from the user standpoint and by direct measurement, before committing to full-scale migration.
Application development is equally suited to the hybrid life, particularly when it comes to testing and debugging.
Here the ability to source processing resources on demand from services, such as the Amazon EC2 , or to develop straight onto a platform like Microsoft’s Windows Azure , can both save money and shorten development timescales.
Other applications, however, are less well suited. Google Apps, for example, has failed to win many users away from the on-premise Office suite, mainly due to its lack of functionality and performance.
Neither have customer relationship management or helpdesk services had that much impact – at least, not as software-as-a-service solutions, although they are routinely hosted on private or public cloud servers rather than in-house.
Availability is a real problem with online storage too
Other applications that struggle include backup, disaster recovery and more general sharing of storage.
Again, that is partly due to a lack of performance, as it is quicker to share files, take backups and recover crashed systems over a Fibre Channel or iSCSI SAN than across the Internet.
Equally, a lack of protocol and API standardisation make it hard to integrate on-premise and cloud storage, especially where more than one vendor is involved.
In addition, hybrid storage raises issues of data security, integrity and ownership. Availability is a real problem with online storage too, with services that come and go – even those from the big boys such as EMC, which last year pulled the plug on its cloud storage platform Atmos leaving its partners to pick up the pieces.
So the upshot is: buyer beware. There are certainly plenty of cloud computing resources that can be mixed and matched with on-premise solutions, and benefits to be gained from such an approach.
You just need to take it slowly, test what seems to makes the most sense, and be sure it is working before taking off entirely into the cloud. ®