Monitoring Large Numbers of Jobs on OpenVMS


If JAMS is executing a large number of Jobs (more than 25) and there is a large numbers of Jobs in the Schedule (thousands), it may be necessary to increase the size of an internal buffer used by the Job Monitor (Monitor Current Jobs). If this buffer overflows, the Job Monitor will clear the list of Jobs and rebuild it. If the buffer overflows before the list can be rebuilt, the Job Monitor will end up looping.


The size of this buffer can be increased by defining the logical name JAMS_LISTENER_MESSAGE_COUNT. This logical must be an integer between 6 and 16. The default is 6, which should be enough for most environments. The following table shows the size of the buffers created for each possible value of the logical name. Each entry is 16 bytes long.

  6 = 64 entries

  7 = 128 entries
  8 = 256 entries
  9 = 512 entries
  10 = 1024 entries
  11 = 2048 entries
  12 = 4096 entries
  13 = 8192 entries
  14 = 16384 entries
  15 = 32768 entries
  16 = 65536 entries

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