As some of you may have already discovered, 7.1 GA2 was released as a 7zip bundle instead of the typical zip bundle. This probably caused a ton of issues. Even our own Dev Tools are not yet equipped to handle 7z files since all the events took up our time.

I will provide you with the reasons why we had to make this move and hopefully, everyone will come to the conclusion that this was the best decision, albeit, the communication could have been handled significantly better.

The original goal that led to providing 7z bundles was to improve startup times. We discovered that if we prepopulate the OSGi state, we were able to significantly reduce startup times by 2-3 times. As we began our testing, our zip bundles were not preserving timestamps correctly. They were rounding our timestamps to the nearest seconds which invalidated our OSGi state. We also found that our bundles had grown to 1.2 gigabytes!

• maintain the original timestamp
• significantly increase the number of duplicate files.

We began to look for solutions. Naturally, tar.gz was the first solution that came to mind. It would easily preserve the timestamps but it did not solve the file size issue. While some people may find a large download acceptable, we did not believe that it would be appropriate for some of our use cases. As a result, someone suggested that we investigate 7zip because 7zip will actually detect for duplicate files and treat them as a single file during compression. This significantly brought down the file size from 1.2 gigabytes to 400 megabytes. It was the perfect solution for us. So this is why we have ultimately decided to use 7zip instead of zips. 

Since our initial development, we have also fixed the duplicate file issue. This means that tar.gz is also viable as a solution (though the bundles are slightly larger at 600 megabytes). From now on, we will be providing 7zip bundles and also tar.gz bundles. Internally we will be using 7zip because ultimately that 200-megabyte difference is still too significant for our use cases, but for everyone else, you guys can decide what works best for you.