PHWinfo - Afficher un message - UW (on AIX) IMAP server occasionally stuck waiting for mlock helper output

12/04/2006, 19h51

On Wed, 12 Apr 2006, Nik Conwell wrote:
> Thanks again for your Mark. What OS did you settle on after AIX
> retired? I'm about to prototype a replacement Intel Linux box.

We made the safe choice: RHE Linux on Intel hardware. Personally, I
prefer BSD, but given how fragmented the tiny BSD community remains it is
no wonder that the organization went with Linux as a more mainstream
solution.

Linux is a good choice, but I wish that they had greater quality control
and compatibility regression testing. A couple of years ago, they broke
the flock() API, and did not respond in a good way when that breakage was
discovered. I think that the problem is fixed now, but it continues to
affect implementors today since the broken kernel was widely distributed
and still runs in many places. imap-2004d and later have the necessary
workaround.

See https://bugzilla.redhat.com/bugzilla....cgi?id=123415 for
details.

As infuriating as that flock() bug was, it pales compared to the issues in
SVR4 (such as Solaris, AIX, HP-UX, etc.). I'm always discovering some new
and non-obvious quirk in SVR4 that requires reprogramming an application
to work around the problem. So it does not surprise me to learn that a
program can be blocked in a read() on a closed pipe on SVR4 instead of
getting an error.

-- Mark --

http://panda.com/mrc
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.

12/04/2006, 19h51	#5
Mark Crispin Messages: n/a Hébergeur:	Re: UW (on AIX) IMAP server occasionally stuck waiting for mlocker output On Wed, 12 Apr 2006, Nik Conwell wrote: > Thanks again for your Mark. What OS did you settle on after AIX > retired? I'm about to prototype a replacement Intel Linux box. We made the safe choice: RHE Linux on Intel hardware. Personally, I prefer BSD, but given how fragmented the tiny BSD community remains it is no wonder that the organization went with Linux as a more mainstream solution. Linux is a good choice, but I wish that they had greater quality control and compatibility regression testing. A couple of years ago, they broke the flock() API, and did not respond in a good way when that breakage was discovered. I think that the problem is fixed now, but it continues to affect implementors today since the broken kernel was widely distributed and still runs in many places. imap-2004d and later have the necessary workaround. See https://bugzilla.redhat.com/bugzilla....cgi?id=123415 for details. As infuriating as that flock() bug was, it pales compared to the issues in SVR4 (such as Solaris, AIX, HP-UX, etc.). I'm always discovering some new and non-obvious quirk in SVR4 that requires reprogramming an application to work around the problem. So it does not surprise me to learn that a program can be blocked in a read() on a closed pipe on SVR4 instead of getting an error. -- Mark -- http://panda.com/mrc Democracy is two wolves and a sheep deciding what to eat for lunch. Liberty is a well-armed sheep contesting the vote.