Consultor Eletrônico

Spawned Servers from Gateway Brokers: How processes work

There has been some confusion over the Processes (Gateway servers)
that get spawned by the Gateway BROKER and when they should "go away".

What follows is an example of what a customer saw as a BUG, and why it
is not:
DOS Client and VMS Rdb Broker running on VMS. The Progress Gateway
broker is started with this command:
PROGRESS/GATEWAY=START/HOST=UVAX2/NETWORK=DECNET/SERVICE=MYBRKR
and when it is started on VMS you see PRO_MYBRKR in HIB state (through
SHOW SYSTEM on VMS).

From the DOS Client connect to this Broker. Then go to the VAX and
you will see PRO_MYBRKR1 that is spawned for that client. On the VAX
with the client still connected to the Rdb file, a shutdown of the
Progress Gateway broker is issued. SHOW SYSTEM shows PRO_MYBRKR is
gone but PRO_MYBRKR1 is still there and the client (DOS) can still
access the data.

THIS IS NOT A BUG! Here is the explanation of why and how come it is
different than Non-Gateway Progress.


***PROBRKR behaves very differently from the Progress broker. After
the PROBRKR spawns off the RDBSRV (i.e.: PRO_MYBRKR1), it has no
communication with the server. The client is directly linked to the
database via the RDBSRV, and PROBRKR is completely out of the
picture. If you shutdown the PROBRKR (i.e.: issue progress/gate=shut
which will shutdown the PRO_MYBRKR process) this will have no effect
on any existing remote-gateway clients. The client will continue to
access the db through the RDBSRV.

The behavior is different for PROBRKR and Progress brokers because
there is no shared memory for foreign databases to keep in synch.
Progress clients use shared memory for synchronization between
clients and servers, so the main broker needs to communicate with the
servers; not so with Gateway brokers.

This example uses Rdb, but it is Gateway generic.

Progress Software Technical Support Note # 10915