Whats so difficult about ISSU

Sat Nov 10 16:48:26 UTC 2012

On (2012-11-11 00:14 +0900), Randy Bush wrote:

> as to whether ios/xe is rtc, you may want to see my preso at the last
> nanog.

NANOG56? I only found RPKI Propagation by you. Direct URL would be
appreciated.

But I really have 0 doubt that IOSd is run-to-completion, exactly like RPD
is. But IOSd indeed seems to have 3 OS threads, while RPD is single
threaded. As I understand RPD does have green threads though, but that is
not helping at all making things simple for JNPR, more if anything, it's
making things more complex.
If native process separation and even native thread separation cannot be
made scale (I'm highly suspicious why it couldn't). Then I wonder why
vendors don't use some existing VM, instead of inventing their own. Many
existing are free and support green threads and native thread and
many-to-many mapping between, so you could get benefit of minimal overhead
of green thread and you get benefit of OS level threading (SMP, scheduling)
to compartmentalize processes.

-- 
  ++ytti