Question

I’m writing a suite of programs for client PCs —

• a Windows Service
• a user-space Windows Forms application

I need to be able to publish an updated version of these programs and have the client PCs automatically and transparently (with no user interaction) update themselves. This update will be done over an unreliable 3G connection (EvDO). The applications will be continuously running, so the update will have to gracefully shutdown the service / close the applications, and then spin them up again after the update.

Before I spend time rolling my own solution, are there any pre-existing solutions for something similar?

Note: ClickOnce doesn’t work here because of the Windows Service as well as several other reasons. I also can’t take advantage of BITS because I’m running against Windows Azure, which lacks the BITS IIS plugin.

Answer 1

Why not consider shadow copy.

Shadow copying enables assemblies that
are used in an application domain to
be updated without unloading the
application domain. This is
particularly useful for applications
that must be available continuously,
such as ASP.NET sites.

Make the programs very simple shells. Then have them watch (FileWatcher) for updates to folder where they were loaded from (and where updates are delivered). Then dynamically reload the AppDomain.

See here and here for more info.

You can use the properties of the
AppDomainSetup class as follows to
configure an application domain for
shadow copying:

Enable shadow copying by setting the
ShadowCopyFiles property to the string
value “true”. By default, this setting
causes all assemblies in the
application path to be copied to a
download cache before they are loaded.
This is the same cache maintained by
the common language runtime to store
files downloaded…