WBM_MSG_LOWER

   WBM_MSG_LOWER is one of three system parameters that are
   available for managing the update traffic between a master
   write bitmap and its corresponding local write bitmaps in an
   OpenVMS Cluster system. The others are WBM_MSG_INT and WBM_MSG_
   UPPER. These parameters set the interval at which the frequency
   of sending messages is tested and also set an upper and lower
   threshold that determine whether the messages are grouped into
   one SCS message or are sent one by one.

   WBM_MSG_LOWER is the lower threshold for the number of messages
   sent during the test interval that initiates single-message mode.
   In single-message mode, the writes issued by each remote node
   are, by default, sent one by one in individual SCS messages to
   the node with the master write bitmap. If the writes sent by
   a remote node reach an upper threshhold of messages during a
   specified interval, single-message mode switches to buffered-
   message mode.

   The minimum value of WBM_MSG_LOWER is 0 messages per interval.
   The maximum value is -1, which corresponds to the maximum
   positive value that a longword can represent. The default is
   10.

   WBM_MSG_LOWER is a DYNAMIC parameter.