原创 Update your software without disruption, thanks to multicore!

 Most of us have installed third party software like Chrome browser or Adobe PDF reader in our desktops. As the vendors keep fixing bugs in their software and keep adding new features, they want to release their updates to the customers.

Typically the new releases are “pushed” to users, making them to suspend their work, wait for the patches/releases to install and then start the work. Sometimes, the IT department wants to push key patches to the OS and they want to reboot the system as well!

This method of installing updates and new versions is full of hassles.

There are primarily two major issues to installing updates – the fact that you have to stop running the software to upgrade it and the fear that an update will introduce bugs. Because of it, many users are wary of downloading and installing updates. In a Swiss survey, 70 per cent of a sample of 50 system administrators admitted they don't always update software for fear of the downtime it will cause – and because 25 per cent of updates can introduce new bugs.

This means that many of us don't do upgrade our software, leaving our computers exposed to crash-prone, insecure code. All this could be change, thanks to an ingenious idea from engineers at Imperial College London.

Computer scientists Petr Hošek and Cristian Cadar have worked out how to employ the unused cores in "multicore" microprocessors to make the update process invisible to the user.

Whenever an update is available, their trick is to leave the old version of the software running on one core – so you can carry on using it – while running the update in parallel on an unused core. They then synchronise the execution of the two programs in such a way that only the most reliable, dependable parts of the two programs run. This apparently limits damage from fresh bugs introduced by the update.

The Imperial team have now successfully tested their idea with Lighttpd, a popular server package used by Wikipedia and Youtube, and Redis, a server program used by Flickr. They shared their results in International Conference on Software Engineering in San Francisco in May 2013.

Putting multiple cores in the desktops and laptops to install patches and upgrades with no disturbance to the user is a cute idea. It puts idling cores to some use till the programmers come up with better ways to use them more effectively!