Machine: 922-200, OS: MPE/XL B.40.00
 
Over the past few weeks we have begun to experience severe 'hangs' on
one of our production systems. Investigation has shown that dbputs to
a detail set may be the culprit. Normally, updates are performed
immediately but now the delay can be from 1 minute to 10 minutes.
During this time glancexl shows the process to be using a lot of disk
i/o (but there is no unusual physical disk activity). Other processess
attempting to write to this dataset are IMPeded (there is item level
locking on all processes).
 
Glance also show potential memory bottleneck (more memory is on order)
but this does not appear to be a factor in this problem.
 
The detail set contains 2.9 million records (cap: 3.6 mill). There are
two search items, the first is to an automatic containing 5.0 million
records (cap: 5.6 mill), the second is to a manual containing 8,519
records (cap: 11411).
 
Capacity changes have been performed fairly recently, but running
'Sample Master Capacity' in DBGeneral on and around our current
capacity for a 10% sampling did not identify anything significant.
 
No configuration changes have been made to this machine recently. The
database is shadowed via Netbase, and also written to from another
machine via NB equations.
 
Effort is underway to archive some more of this data but will not be
happening immediately. Has anybody experienced had any similar
experiences, or have any insight to offer?
 
Also, are there any tools that will simulate the actions required when
an image intrinsic is executed? I would be interested to see how many
(bitmaps of) records in the masters are read through to find an empty
slot when the primary calculated address is already filled.
 
Thank you,
 
Gary Clarke
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