tunable parameters problem?

[Piercarlo Grandi]

In article <27 at holston.UUCP> barton at holston.UUCP (barton) writes:

    I am curious if there is some sort of limit on the number
    of times a single user can open the same file in SCO 2.2.1
    on a 286.

I would like to know too; there is a limit on the number of processes
the same userid can have, no matter how many times he is logged in, but files
ought to be openable without problems.

    My problem occurs when the vertical package I developed is
    running with 4+ users doing inquirys in the same masterfile.

Your masterfile is opened by four different instances of the application, or
it is a centralized server application attached to four terminals? If the
latter, check with the number of open file descriptors for that process.

    Problem: eventually the system will refuse to open the files requested
    for a particular user, no errors are generated other than those in the
    application.  The files are RM/Cobol indexed data files. 

    Is there some parameter I can adjust? I am nowhere near the
    limit of 300 open files systemwide.

A possibility is that you are bumping into a limit on the inode table or the
file table or the lock table. For the inode table, that is difficult; if the
same file is opened multiple times, only one inode is taken up. On the other
hand the file table usage grows with each open() because a different file
pointer needs to be allocated. I think it is probable that your Cobol library
rather does lock the file (especially as being indexed it wants to protect
its internal structure consistency), and by default most systems come with a
rather small lock table. Check that first.

    Since all the users log in under the same name to start the
    application, I suspect that I am bumping into some limit.

Yes, probably you bump into some limit, but probably not one related to the
fact that the same name is used (unless your cobol library spawns off
multiple processes to access the indexed seq file). It is a remote
possibility; just in case, check about that. The limit is tipically 20-25
processes per user id (number, not name -- look at ps -l).
-- 
Piercarlo "Peter" Grandi           | ARPA: pcg%cs.aber.ac.uk at nsfnet-relay.ac.uk
Dept of CS, UCW Aberystwyth        | UUCP: ...!mcvax!ukc!aber-cs!pcg
Penglais, Aberystwyth SY23 3BZ, UK | INET: pcg at cs.aber.ac.uk