----- Original Message ----- From: "Paul Jakma" <paul@clubi.ie> To: "Alexei Roudnev" <alex@relcom.net> Cc: "Michel Py" <michel@arneill-py.sacramento.ca.us>; "Nanog" <nanog@nanog.org> Sent: Wednesday, August 04, 2004 2:39 AM Subject: Re: Quick question. --- snip ---
Not really.. this is a resource exhaustion problem, and you can not cure this, given buggy apps, by throwing more CPUs at it.
Let's say you have some multi-process or multi-threaded application which regularly spawns/forks new processes/threads, but it is buggy and prone to having individual processes/threads spin.
So one spins, but you still have plenty of CPU time left cause you have two CPUs. Another spins, and the machine starts to crawl. So you solve this problem by upgrading to a quad-SMP machine. And guess what happens? :)
the second cpu buys you time - it is unlikely you're going to be able to react in time on a busy single cpu box with a runaway process (it launches into a death sprial almost immediately), but you would usually have 10-15 mins on a dual cpu box at a minimum or maybe infinity if you enforce cpu affinity for apps that tend to misbehave. paul