Tuesday, February 21, 2006

Federated Data, backup and recovery, or how to recover from a BSOD

One impact of more powerful desktops and things like Windows Workflow Foundation (WWF) or even the ability to run "lightweight" application servers on desktops is that information is going to become more and more federated with challenges around data-synchronisation increasing ever further. Service state (if using WWF for example this would be business process state) will become distributed around the organisation, not always stored on "nice" central databases that can be backed up centrally. This means that backup and recovery, and potentially encryption, of this information is going to become more important and of course more challenging.

Taking an example from myself today and using email as the semi-critical information. I take regular (once a week) backups of my files, but today the following happened: I copied all my emails off the Exchange server into local folders (business state local) and then installed a new piece of software (a firewall) that promptly fried the machine resulting in a BSOD, and a failure of Windows Safe mode to start. This meant that I'd just lost the "state" of the last 2 days, which is a bit of a pity as that includes where I'm meant to be tomorrow and some emails that I could do with still having. Now my backup could take me back to Saturday, but this would mean (in our Service analogy) having some pretty complex compensation logic in the center to cope with "lost" service and process state. The requirement therefore was to access the disk itself to get the raw (but encrypted) information for re-entry into the last saved state.

If you are looking at future challenges for your enterprise look no further than having services and business process living across the enterprise across multiple application environments, many of them under direct user control. Architecturally this is fine in a decent service architecture, but for implementation it is not the sort of area to get into lightly. Distributing services across the network and to users makes a lot of sense, but the challenge of federated data and federated context as well as the pure technical challenges of invoking user centric and specific services are one area that organisations need to plan heavily for before making the leap.

As an aside the solution was to get a Linux Live CD (Slax) and copy the elements onto a USB key, this was after Windows Recovery also failed to help.

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