[Info-vax] OpenVMS servers and clusters as a cloud service

[Stephen Hoffman]

On 2018-01-09 18:11:06 +0000, Scott Dorsey said:

> Stephen Hoffman  <seaohveh at hoffmanlabs.invalid> wrote:
>> 
>> I'd like to see the ability to restart and recover far more widely 
>> used.  But what's out there now in OpenVMS?  That's clearly not getting 
>> used widely, not viewed as useful, not capable, or whatever.  Which 
>> means either developers and project managers have to change their whole 
>> approaches here — and sure, like that's going to happen — or the 
>> provided APIs and approaches have to be made easier and more 
>> transparent and clearer to the developers.  And made easier and more 
>> visible and valuable to end-users, for that matter.
> 
> VMS has no automatic process checkpointing facility, which is a shame 
> because it might not be a difficult thing to add to VMS.  Unlike with 
> Unix, most processes aren't going to have lots of children so just 
> checkpointing a single process would be possible and then arranging a 
> restart from the last time it was snapshotted would be likely possible.

Having been down that path and having remembered VAX FastBoot, 
restoring the file states and the network connections is a whole lot 
more complex on OpenVMS than might be realized.

Most knowledge of FastBoot went down the memory hole a couple of 
decades ago, though.

> That said, I have been writing code since the early 1970s which 
> manually wrote process status to a checkpoint file to allow manual 
> restarts of long jobs.  There's no reason not to do it, other than 
> coding time.

If there were no other reasons, then such recovery would be more common 
than it is.   If it's not common, ask why.   Because the restart is not 
needed?  Because restart not important?  Or because folks don't have 
knowledge or the skills or the time to implement that capability?   if 
it's desirable to some folks and not easy, then maybe making it easier 
to achieve is a competitive and marketable feature?  Marketable to 
end-user developers and to ISVs, that is.

But then VSI has more than enough other work on their schedule.


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