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Re: .0
> What, if any, relationship does the USERNAME that the historian
> background is running need to have with the USERNAME that an instance
> of DECmcc director has?
No relationship, except that they have to be in the same UIC group
(this is one of the ways how system manager can control access to the
domain).
Multiple users are able to record data in the same domain but only one
background process is required ( when several users share Historian in
the same domain be sure that they use the same MIR).
> It also appears that I need a historian process for each domain I
> want to record data for?
Yes. You need a background process for each domain.
> Assuming I have lots of historian processes, it would be nice if the
> process name reflected the domain it was recording for.
In VMS a process name length is limited by 15 characters.
The Domain name can be specified either by Simple Name or by Full Name
and there is no guarantee that 15 characters are enough for uniqueness.
Sam
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| Ok, the user that initiates a RECORD must be in the UIC group as the
user who SUBMITs the background.
I sense that there is some other relationship here that I must be
overlooking. Are there any access issues around disk directories
other than MCC_COMMON, the directory of the issuer of the RECORD and of
the directory of the person who submitted the historian?
What about cases where one person creates a domain but many other
people (on seperate systems perhaps) use the domain and create maps
that are the domain (and it's entities of course). Who can initiate
recording and what are the issues here?
Thanks
s/rob
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RE: .2
> I sense that there is some other relationship here that I must be
> overlooking. Are there any access issues around disk directories
> other than MCC_COMMON, the directory of the issuer of the RECORD and of
> the directory of the person who submitted the historian?
Both the issuer of the Record directive and the background process
have to have read/write access to the domain directory ( historical data
and all Historian information are stored in this directory).
> What about cases where one person creates a domain but many other
> people (on separate systems perhaps) use the domain and create maps
> that are the domain (and it's entities of course). Who can initiate
> recording and what are the issues here?
Every one who has right privilege (see above) can initiate recording.
The domain directory is an argument in the Create Domain directive.
By playing with protection of this directory you can allow, for
example, the users from the same group to specify recordings directive
in this domain (read/write access) and all others only to do Show Recording
and Show historical data (read access). Or you can make these recordings
and historical data invisible for users outside of your group.
For example, such schema can be used:
- owner of the domain (the person who creates this domain) is
able to specify all Historian's directives: create, delete,
modify and so on;
- users from the same group are able to do only Show recording
and Show historical data;
- all others have no access to Historian and historical
information.
Sam
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