IDMS

  • 1.  Re: External run units

    Posted Feb 08, 2007 05:03 PM
    Pete's point about distinguishing between ""external Request Unit"" and
    ""external Run Unit"" is well taken. The number of External Request Units
    (ERE's are the limiting factor) is limited by MAX ERUS, and also by the
    number of CHECK USER TASKS (CHKUSERTASKS) - this determines the number
    of subtasks allocated to detect abnormal termination of external request
    units. I believe that if CHKUSER tasks is other than zero (disabled) you
    should keep its value and MAXERUS the same. With the wide range of
    sources of ERUS requests it will be hard for you to determine an
    appropriate number. We are luckier in that all our request units are
    either internal (we don't run CICS - we're a IDMS-DC shop) or batch - so
    we match our MAXERUS to the number of batch initiators and this seems to
    work fairly well.

    Back to distinction between External ""Request Units"" and ""Run Units"". I
    have tested a batch program that has bound (for academic interest only)
    hundreds of ""Run Units"" - and only one ""ERUS Task"" (that is one ERE) is
    allocated (a developer wanted to know if there was a ""practical"" limit
    to the number of run units a batch region could bind). If I run the same
    program in two regions at the same time I get two ERE's allocated - and
    2*hundreds of Run Units. The same behaviour is exhibited in IDMS-DC
    where an ADS task can LINK to DC-Cobol programs that each open their own
    Run Unit and keep them bound for subsequent LINKs within the same task -
    you only see one IDMS-DC task but there are multiple ""secondary LTE's""
    allocated that represent the different Run Units associated with the
    task. There is a chain of secondary LTE's from the ""primary"" (i.e. ""real
    VTAM, UCF, CCI, etc) lterm.

    As for the CA-Server question - we are now using the IDMSJSRV task
    running inside IDMS-DC using the Release 16.0 CA-Server listener task
    across TCP/IP. I tested this morning to double check (I wouldn't want to
    mislead the list - people have been shot for less I know) and as you
    would expect since IDMSJSRV is an internal IDMS-DC task the run units
    show up as being associated with that task - which is to say they do NOT
    run as ERUS tasks. I am not in a position to check on the old CCILINE
    tasks.

    I know this doesn't help much - but somebody out there might be
    interested.

    Cheers - Gary