Dear Tru64ers,
Only one person replied, but he was extremely helpful. Tom Webster
says that he too found that the class daemon kept on falling over, so
he wrote a cron job to run every 5 minutes to make sure it was still
alive. He also said that the enabled status seemed to be magically
retained across system reboots.
I have a suspicion that the resilience of the daemon is related to how
often it is configured to check class CPU usage. Initially I used the
default 1 second interval and the daemon would only stay up for a few
minutes. I switched to 5 seconds and so far (nearly a day) it has
stayed up. Tom says he uses 3 seconds and sees occasional failures.
Despite these problems Tom says the scheduling works pretty well on
their system which is a primarily batch environment with some
interactive Matlab users as well. My goals are different:
(1) stop netscape gobbling up all the CPU power it can lay its hands on
(2) allow a research group to fund an extra CPU and have priority
access to the extra power they have bought.
I still have some concerns, though I think they can be lived with:
(1) runclass ought to have a switch which allows you to run the
program even if class scheduling is disabled.
(2) runclass ought to document its exit status.
(3) the security on runclass is very weak. Any user can use it to
switch to a class with a lower CPU ration, which might be attractive
if nobody else is using that class. I think the administrator should
be able to configure each class whether runclass is allowed on it.
Original message:
>
> I have just been experimenting with the class_scheduling feature in Tru64
> 4.0E and at first it looked absolutely wonderful, but then I hit a couple
> of snags:
>
> (1) it worked well for a few minutes but then became disabled. In kern.log
> are messages like:
> vmunix: The class scheduler daemon is not responding. Class scheduling
> has been disabled.
>
> (2) I was hoping to make use of class scheduling by putting the runclass
> command in the wrapper script which runs netscape. Unfortunately the
> runclass command fails if class scheduling is disabled...this accords with
> the man page but is not very helpful. So if I were to install this then
> netscape would become unavailable whenever class scheduling were disabled
> for any reason. But I guess I can produce some shell script jiggery-pokery
> to get round this.
>
> I am also puzzled as to what happens at a reboot. There are no class_admin
> commands in any of the /sbin/init.d scripts: do I have to write one myself
> or is there some magic way by which the enabled status is retained?
>
> I am running 4.0E with patch kit 2, and can't find any class_daemon core
> files.
>
> Any hints from others who have run the software would be very welcome.
>
Regards,
Bob
--
==============================================================
Bob Vickers R.Vickers_at_dcs.rhbnc.ac.uk
Dept of Computer Science, Royal Holloway, University of London
WWW: http://www.cs.rhbnc.ac.uk/home/bobv
Phone: +44 1784 443691
Received on Tue Jan 18 2000 - 11:37:56 NZDT