I know some parts of this discussion have been addressed here and there, but
I couldn't find very much--perhaps that is because the documentation is
pretty good.  I think I have setup the proper parameters but would like to
bounce the idea of some of you here.  I have a pretty simple situation and
figured the defaults were good enough, but now some queries are getting
longer and I've been getting complaints of timeouts and see some LogEvents
on the server with the message, "The Session ID # is no longer present on
the server."  So I need to make some changes.

The server is running EDB 2.05b10 on a Windows 2008 32-bit server, hosted
over the internet.  Each of the 6 users of the custom Delphi application
(with the EDB components of the same version) is connected remotely from a
different location--there is no central office.

Here are the Server settings:
 Session Timeout = 1800 (30 minutes)
 Dead Session Interval = 300 (5 minutes)
 Dead Session Expiration = 1800 (30 minutes)
 Maximum Dead Sessions = 20

Here are the Client settings:
 Remote Pinging = 45
 Remote Timeout = 300 (5 minutes)

I've got an OnRemoteTimeout event hooked up to ask if the user wants to try
to reconnect if it encountered a timeout.  If they answer No, the
application terminates.

It pings frequently--the session shouldn't die when the user steps away from
the computer. (If there were hundreds of users, I probably wouldn't want
each one to be pinging that often.) If their internet connection goes down,
they have an hour to recover and reconnect before their session is killed on
the server (30 minutes before it's considered "dead" and another 30 minutes
before the dead session is killed).  The client's timeout has been upped
from the default of 180 seconds to 300 to be much longer than the longest
query should take.

Since a test environment doesn't always see the same problems the clients do
in production, I first set the parameters really low on the server so it
would be easy to get timeouts.  Then I upped them to make sure those
problems went away.  I believe I've resolved the problem, but am wondering
if what I've done is too extreme or if there are other issues that might
creep in with these values.

One other consideration is that some of the users work on laptops and might
close the lid to put the computer to sleep, then reopen it later.  If they
left this application on, and try to reconnect with an hour, it should find
the session and reactivate it, right?  Is there any problem with upping the
Dead Session Expiration to several hours?

Any thoughts?

David Cornelius
Cornelius Concepts

David,

<< One other consideration is that some of the users work on laptops and
might close the lid to put the computer to sleep, then reopen it later.  If
they left this application on, and try to reconnect with an hour, it should
find the session and reactivate it, right? >>

Yes, that is correct.

<< Is there any problem with upping the Dead Session Expiration to several
hours? >>

Well, the problem with a very long dead session expiration time is the
possibility of locks being held for that time period.  One can always
manually remove sessions in such a case, but it's usually easier to have the
EDB Server do it automatically.  However, that can clash with the
requirement of long-running sessions on the client application that need to
reconnect periodically.

--
Tim Young
Elevate Software
www.elevatesoft.com

Thanks for the reply and for confirming my thoughts on the idea.

David Cornelius
Cornelius Concepts