Ok, since we installed Ruby 1.8.6 the GC (Garbage Collection) does not take 50 secs (or more) to do its job when our Application is around 2 GB big. The time is down to about 20 secs – and – the Speed at witch the queries are delivered is up up up! Thank you for fixing this, Dear Ruby Community.
Update: I must actually elaborate a bit. The GC used to force us to do a restart because it took such a long time to do its job. With Ruby 1.8.6 the memory usage still “grows” throughout the day. This just has less impact on our Service as we have 12 GB of memory on your server. We still want to find out what increases the memory consumption of our software, though. We owe that answer to Ryan Davis.