The GPLv3 is now an option to the Unicorn license. The existing GPLv2 and Ruby-only terms will always remain options, but the GPLv3 is preferred. Daemonization is correctly detected on all terminals for development use (Brian P O'Rourke). Unicorn::OobGC respects applications that disable GC entirely during application dispatch (Yuichi Tateno). Many test fixes for OpenBSD, which may help other *BSDs, too. (Jeremy Evans). There is now _optional_ SSL support (via the "kgio-monkey" RubyGem). On fast, secure LANs, SSL is only intended for detecting data corruption that weak TCP checksums cannot detect. Our SSL support is remains unaudited by security experts. There are also some minor bugfixes and documentation improvements. Ruby 2.0.0dev also has a copy-on-write friendly GC which can save memory when combined with "preload_app true", so if you're in the mood, start testing Unicorn with the latest Ruby!
Ruby 2.0.0dev is the future and includes a CoW-friendly GC, so we shall encourage folks to give Ruby 2.0.0dev a spin.
We don't need it because we don't test old Rails with bleeding edge Ruby.
Even LANs can break or be unreliable sometimes and socket disconnect messages get lost, which means we fall back to the global (kill -9) timeout in Unicorn. While the default global timeout is much shorter (60s) than typical TCP timeouts, some HTTP application dispatches take much I/O or computational time (streaming many gigabytes), so the global timeout becomes ineffective. Under Linux, sysadmins are encouraged to lower the default net.ipv4.tcp_keepalive_* knobs in sysctl. There should be similar knobs in other operating systems (the default keepalive intervals are usually ridiculously high, too high for anything). When the listen socket has SO_KEEPALIVE set, the flag should be inherited by accept()-ed sockets.
We favor low latency and consistency with the Unix socket behavior even with TCP.