Why alpha.2? We made improvements to alpha.1, before it was released. Every tag starts an automatic release and we are strictly following Semantic Versioning here at Graylog. You can find

We’ve just released Graylog v2.0.3. This release includes many bug fixes and improvements, and upgrades are recommended.

We’ve just released Graylog v2.0.2. This release includes many bug fixes and improvements, and upgrades are recommended.