Noulakaz

The blog of Avinash, Christina, Anya and Kyan Meetoo.

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Synchronizing two computers using Amazon S3

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I’ve moved to Amazon S3. I can now store 1Gb of data online at $0.15 per month (Rs 5). Transfers cost $0.20 per Gb (Rs 6.50). This is extremely cheap for the peace of mind you can enjoy when you know “your data is safe sitting on Amazon’s geo-redundant servers right between some bits describing a new book from Oprah and a bad review on latest Ben Affleck movie!”

I have downloaded and started using Jungle Disk and it works great! Jungle Disk (simply said) allows you to mount your S3 online storage as a normal drive. It even caches data and transfers in the background so, in most cases, you don’t even think you are working online. It is multiplatform (Linux, Mac OS X and Windows) and is free (for the time being – the source is also available)

This is all great… except for one major issue: I don’t want to do backups! I want synchronization!

Let me explain. I use my MacBook at home and one Linux PC at work. I want to be able to access my files both at home and at work. Naturally, I can do this by moving all my files to S3 and then use Jungle Disk to access them transparently. Unfortunately, this scheme does not work when the Internet connection is down and no local cached copy of the data exists. And having no Internet connection in our poor country is relatively common.

One solution would be to have the data locally on the MacBook and on the Linux PC. Then S3 would be used as an intermediate to synchronize the two computers. Unfortunately, I have no idea how to do this. I’ve been reading about s3sync.rb and rsync (over the Jungle Disk mount) but I do not understand how to do file synchronization with them. I’ve also read about unison but I am not too confident of its performance with respect to S3…

Any idea?

HTML5 is here

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HTML5 is here courtesy of our friends from WHATWG. HTML 4.01 will have an officially sanctioned successor after all. For me, this indicates that XHTML 2.0 has no raison d’être now but who knows?

HTML5 has a bright future. And so has CSS and Javascript. I would advise all aspiring Computer Scientists to get familiar with the latter. Javascript is an extremely powerful programming language and will power the client-side portion of many of the applications we will use in the future.

I’ve just discovered Apple Keynote

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Apple, besides inventing great computing devices and operating systems, also develops a lot of software. I’ve already blogged about iLife and third-party iLife-enabled applications like Comic Book.

Apple also does iWork which contains two applications. The first one is a word-processor / desktop publishing program called Pages and the second one is a presentation software called Keynote. The next version of iWork will (if rumours are true) contain a spreadsheet.

For some profound reason[1], I decided to give Keynote a try today (I’ve installed the 30-day demo version) and I must say things look good.

In a nutshell, Keynote

  • Read and writes Powerpoint files
  • Integrates with iLife (photos, videos and music)
  • Renders presentation beautifully
  • Offers a number of Apple-designed themes
  • Supports 3D transitions using OpenGL
  • Exports presentations in Quicktime, PDF and Flash formats (the Flash export is particularly interesting because I want to have my presentations on the web)

I’ll use Keynote for some of my next presentations to see if it is good enough compared to OpenOffice Impress which I currently use.

One nice rule to follow when doing a presentation is the 10/20/30 rule by Guy Kawasaki. A fantantic website with lots of resources and insights on presentations is Presentation Zen by Garr Reynolds. This page is particularly relevant.

I’ll keep you updated.

[1] The profound reason is that I want to become a better teacher. Some of my students might have some difficulty with my style of teaching and I want to explore some new avenues…