IMS Master Terminal Elimination by nyut545e2

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									IMS Master Terminal
    Elimination
     Frank Fleming


     Barclays Bank plc



            30/06/00     1
Introduction

❖   Repeat of Presentation from 1991
    – Barclays have run without MTO Terminal since
      that time
❖   Discovered that some installations still using
    (and moaning about) the MTO terminal
    – So decided a repeat might be worthwhile




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Contents

❖   MTO Terminal - What is it
❖   Barclays Previous MTO setup
❖   Why eliminate the MTO
❖   Tools available
❖   Problems to be solved & Solutions
❖   Post Implementation problems & Solutions
❖   Further MTO enhancements
❖   Summary

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MTO Terminal - What is it? - 1

❖   Dedicated terminal for controlling IMS
    subsystem
    – A relic from the dim and distant past
    – Possibly a teletype
    – Or a loose VDU/Printer combination
       x   Master/Secondary




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MTO Terminal - What is it? - 2

❖   MTO Terminal(s) have LTERM(s)
    – Applications can queue messages to MTO
       x   To Master and/or Secondary
    – LTERMs can be reassigned
❖   3270 Master
    – Formatted screen
    – Must have a secondary printer




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Barclays Previous MTO Setup

❖   Originally 3270/3270P combination
    – Some SLU2/SLU1
    – Always having trouble with printer
    – Sysprogs couldn’t see messages
❖   Secondary became SYSOUT=*
    – BTAM line with DD statement to sysout
    – Bliss - we could now see what was going on
❖   Sysprogs used IMF/SM
    – Now Mainview for IMS

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Other Operational Facilities

❖   Command Processing BMP
    – Issues commands via CMD (type 1 AOI) call
       x   Audit trail to Secondary LTERM
    – Used to offline DBs or Areas for Batch IC
       x   Or recoveries
❖   IMF EXECs
    – Operator, time, message or batch initiated
       x   Audit trail to IMF Journal
❖   Automated Operations
    – Commands entered via IMS WTOR
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Why eliminate the MTO

❖   The terminal not the person (initially)
❖   Not a Single Point of Control
❖   Inability to control multiple IMS systems




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Why Eliminate the Master

❖   Screen layout is horrible
❖   Messages queue when message area full
❖   Have to use PA1/2 to scroll large displays
❖   No backward scrolling
❖   Application messages in different queue
❖   Many IMS messages are irrelevant



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Why eliminate the Secondary

❖   >45,000 lines per day
    – All going to JES spool
    – System up for a month at a time
       x   2 Months - Dec-Jan
       x   >1.35 M lines to JES Spool
       x   Impossible to scroll to end or find things
❖   Invisible after system closedown
❖   Contents virtually a duplicate of IMF Journal
    – But does include application messages

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Tools Available

❖   IMF
    – Message Journalling
    – Command Input
❖   Dummy Devices for Master
    – Somewhere to hide the MTO
    – OS Console
       x   Reassign MASTER LTERM
    – TAF Session via NETVIEW
    – Dummy 2741 teletype

                            30/06/00   11
Problems to be Solved - 1

❖   IMS gen requires an MTO
    – Define as 2741 on BTAM line
❖   Messages queueing to MTO
    – Message suppression via AOI exit
       x   IMF provides this




                               30/06/00   12
Problems to be Solved - 2

❖   Application messages to IMF Journal
    – Write MPP to take messages from queue
       x   Change Master & Secondary LTERMs to TXNs
            – Had to be careful where MSC links involved
    – MPP schedules IMF EXEC to write message to
      journal
       x   Horrid - but it did work (sort of)




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The bits we didn’t do

❖   ‘BADSTAT’ messages
    – Routine called for bad status codes or abends
    – Messages to MTO - LTERM MASTER - OK
    – Formatting of PCBs & Storage
       x   Info not relevant to operations
       x   Too much garbage for the operations journal
       x   Does anyone actually look at this anyway?
❖   Master/Secondary message duplication


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Post Implementation Problems - 1

❖   MPP for Application Messages didn’t work
    well
    – IMF batch EXEC facility not designed for MPR
      environment
    – Replaced by small usermod to DFSCMD30
       x   Fake CMD call ‘MTOMSG’
       x   Causes DFSCMTI FUNC=MSG to be issued
    – Simplification allowed by CMD call meant that
      multi-seg can now be handled
    – Words become just words again - not parms

                            30/06/00                  15
Post Implementation Problems - 2

❖   Messages queuing to MTO during closedown
    – More of an irritant than a problem
       x   But the messages can build up across multiple restarts
    – Flag in SCD - Queues unavailable
       x   Set during closedown
       x   AOI exit not driven to suppress messages
    – Simple really - schedule IMF EXEC to dequeue
       x   But ...




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Further MTO Enhancements - 1

❖   IMF Journal Archiving
❖   IMF Security
❖   Multiple IMF system connections




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Further MTO Enhancements - 2

❖   Connection to Comand Post




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Summary

❖   We didn’t like the old style MTO
❖   So we got rid of it!




                       30/06/00        19

								
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