[Info-vax] Logging systartup_vms.com progress to operator.log VMS 7.3-2

[David Jones]

On Wednesday, October 14, 2020 at 10:55:23 PM UTC-4, geze... at rlgsc.com wrote:
> Being able to automatically spawn several tasks in parallel has been a great benefit on more than a few occasions.

I wasn't aware the startup driver spawned its procedure invocations. Good to know, buy systartup_vms is still the
supported way for sysadmins to modify startup.

As an exercise, I wrote a startup driver for my little cluster that was driven by a relational database. The schema has
a components tables that describes the startup items(including their phase), a startup table that organizes component
by node or node group alias (e.g. 'ALL'), and view for each node that extracts and sorts the components that node 
needs to run at boot. The startup driver spawns multiple components to run in parallel with a barrier between each
phase.

The main purpose of this startup driver, though, was that the output of the spawned components was a mailbox that
the driver read to produce the boot log. The log tagged each line with the component that generated it, greatly helping
you track down otherwise mysterious warning messages that may occur.  The tag also included a timestamp relative
to the spawn time of the component so you could determine the critical path for the startup.