
DCOM remote client / server - resiliency, reliability ??
Client is a VB application. Server is a remote (or COULD be used on
the same computer as the client) out of process EXE server. All
machines are NT 4.0.
Seeking advice on resiliency and reliability.
Experimenting, I have attempted deleting the remote server process:
A [Switch to..] [Retry] box appears (cancel is always ghosted).
I would rather NOT have this box appear, but rather IMMEDIATELY
get a trappable error in the client. I would use this to
de-instantiate the object, and start the server on a different
computer. Is there ANY way to get an ERROR rather than this box?
The SWITCH TO / RETRY box is sticky. It seems I can't do anything
with the object when it gets in this mode. Is there a time-out
involved? Would the box go away eventually?
Surely there must be some clean way to wind this down, and let the
application continue to live a useful life?
Experimenting, I have attempted to delete the client process:
The server continues. A new client can be started, but the
server process lifetime no longer seems to be tied to the client
in this second life. I presume reference counting keeps the server
alive. What I would REALLY like is for the SERVER to go away, as
soon as possible, automatically, if the client gets blown away
for some reason. What is the best way to accomplish this?
I've thought of a PING timer in the server, which on 5 second
intervals will attempt to raise a do-nothing ping event back to
the client. If the RAISE fails, then assume the client is gone,
and exit the server. Does this sound like something that will
work?
I have not done that much with REMOTE servers, but these seem like
really basic issues with DCOM, so my hope is there are proven ways
to deal with them. Please let me know if my expectations are too high.
The overall goal is for high reliability, resiliency, and self
recovery. Any hints, tips, or suggestions to this end would be
greatly appreciated. The applications involved help control
electricity exchanges for the power industry. I'm looking for
anything and everything that will make this more reliable.
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______________________________________________________________________
Lee Gillie, CCP Remove NOSPAM to E-Mail
Online Data Processing, Inc. - 3501 N. Haven - Spokane, WA 99207-8500