There were quite many changes under the hood, including a lot of clean up work and making it future-proof by updating dependencies, using modern Java, OSGi and testing concepts and more.
I think it a great achievement that we were able nonetheless to make all of the 2.x add-ons available on this milestone.
We do not yet have a structured documentation on all relevant changes from 2.x to 3.x and no step-by-step migration guide, but here are a few major functional changes that I’d like to mention:
The runtime now requires Java 11 instead of Java 8, so please make sure to install an appropriate JVM.
Most visible change is the new UI, which comes with a setup wizard and which replaces Paper UI and HABmin and also serves as a very powerful end-user UI.
The next-gen rule engine (NGRE) of openHAB 2.5 has now become the official rule engine within openHAB. Good news is that your rule DSL files are not impacted by this change and should run smoothly on it. The only change you’ll have to look our for in your rules is the fact that rules now use Java Time API instead of Jodatime, so some expressions need to be slightly adapted.
The compatibility layer is gone, so if you still rely on any 1.x add-ons, better help porting them.
The admininstration-related parts of the REST API are now secured, which eliminates many potential attacks from malware in the local network. As a side-effect, some inofficial/custom 3rd party integrations might not work anymore as expected.
So while this milestone build is meant for early-adopters, which are willing to invest some time and that are not asking for any detailed documentation, I can say that the runtime itself is already very stable. I am personally using it as my production system (with more than 20 add-ons) since a couple of weeks and do not have any stability issues or broken features. A couple of other maintainers already followed this “eat your own dogfood” principal and are likewise confident in the overall quality.
It is fantastic to see so many people having tried out the first 3.0 Milestone and reporting bugs and enhancement suggestions.
Likewise, I am happy to see that many add-on maintainers have successfully switched to 3.x development and continued to provide a constant flow of fixes and improvements of the add-ons!
All these activities together brought us a great step forward, so that we are happy to make Milestone 2 available today! It includes a huge number of changes for the short period of just 3 weeks since the first milestone.
From now on we plan to do weekly milestone builds for openHAB 3 and plan to stick with the release date before christmas. The current plan for the upcoming releases therefore looks like this:
Nov 29: 3.0 M4
Dec 6: 3.0 M5
Dec 13: 3.0 RC1 (feature freeze)
… critical fixes with further RCs …
Dec 21: 3.0 GA
With this focus on 3.0, we will reduce at the same time the release frequency for 2.5.x. We will continue to provide patch releases also well into next year, but only do those releases whenever a couple of fixes piled up. 2.5.11 probably makes sense early December, a 2.5.12 would then follow next year only.
Please use this topic for all discussions around the new Milestone build - thanks and have fun!
A short heads-up here: Thanks to prompt community testing, at least two issues (this and this) have been discovered on Milestone 4, so it might be advisable to wait for their fix and use M4 only for testing, but not for any productive use. Sorry for any inconvenience.
A quick heads-up: Since we have built 2.5.11 today, RC1 is postponed until tomorrow.
Note that with RC1 we will have a feature freeze, i.e. the remaining days will be focussing on bug fixes and making everything as stable as possible.
With only one week left for the final release, all eyes are now on bugs, bugs, bugs. If you come across anything that you consider critical, please immediately report it on Github and make sure you are heard. This is especially important for the core runtime as bugs there impact all of our users, but also broken add-ons must be considered likewise critical.
Please use this thread for any questions and discussions - thanks!
The final 3.0 release is approaching rapidly! We just released RC2, which should include fixes for all critical open issues - unless somebody point out something tremendously broken, this is what you can expect for the final release on Monday.