Pgbouncer is able to do online upgrade (like e.g. nginx). Here is info about it: http://pgbouncer.projects.postgresql.org/doc/faq.html#_how_to_upgrade_pgbouncer_without_dropping_connections It's enough to start new process with added new swith "-R" to do upgrade.
I've experienced issues with this (crashing, not working properly and whatnot), so that's why I chose to leave it outside for now. I can't say those were within the last two releases, and my personal reason't aren't really valid for more than me.I'll update the init script to add this, thanks.
Hmm, once time pgbouncer -R (version 1.5) didn't detach from terminal. I couldn't reproduce it, i assumed it was accident. But it seems "upgrade" isn't perfect stable.
Created attachment 334118 [details] pgbouncer.initd This new init script adds support for upgrade. It also fixes bug 410645.
+ 14 Jan 2013; Sergey Popov <pinkbyte@gentoo.org> files/pgbouncer.initd: + Update initscript, fix bugs #410645 and #410647, thanks to Johan Bergström
