As a part of my consultancy job, I have a pleasure to help various customers with problems that could be described collectively as GC-related (or memory-related in general). One day Tamir Dresher from Clarizen company (BTW, an author of Rx.NET in Action) contacted me with such an extremely interesting message (emphasis mine):

We are experiencing a phenomenon of GC duration of 15 minutes in our backend servers.¬†(…) Do you think we can have a session with you and perhaps you’ll have ideas on how to find the root cause?

15 minutes! That’s an infinity! If we see something like this, one thought comes to mind – something really serious must be happening there! As nowadays most of such problems may be diagnosed remotely, after signing NDAs we could go straight into attacking the problem. Clarizen has provided a very well-prepared and concise summary of their architecture and current findings.Continue reading