🚀 go-pugleaf

"Remy Lebeau (TeamB)" <no.spam@no.spam.com> wrote in message 
news:45ac97b6@newsgroups.borland.com...
>
> Then you are doing something wrong in your server code.  Even if a
> client is lost abnormally, your code should not be hitting the CPU
> that hard.  If it is, then you are not protecting your code properly.

I know that!  I just don't know what is wrong yet because the application 
has been working fine until this abnormal disconnect issue came up!


> Then the client is likely being disconnected abnormally on its end of
> the connection, probably by a firewall or a faulty network.  The
> server cannot detect abnormal disconnects from its end in a timely
> fashion.  To do that would require you to implement a keep-alive
> mechanism into your data protocol.

It isn't *my* protocol and keep-alive isn't supported.


> What you have described is
> certainly not a graceful disconnect, which leaves only an abnormal
> disconnect.

Okay, that's good to know, and gives me something to pass on to the 
customer.


> Your server code needs to keep track of idle periods on each
> connection, and then close any connections that sit around doing
> nothing for awhile.

Which I am already doing...


>> Below is a *simplified* snippet of my TCPServerExecute method.
>
> That is hardly simplified.

Sorry, I meant logic-wise.  All the code does is receive the data and handle 
exceptions.


> You don't need exception handlers to know what is going on with the
> client.  ReadFromStack() reports that information.  Try the following
> code instead:

Okay <code snipped>, I'm not an Indy expert and wasn't aware of this method. 
Thanks for the code, though I probably won't change anything right away 
since it doesn't solve the immediate problem (but I will pull out the debug 
exception handlers).


> During a graceful disconnect, yes.  Graceful disconnects are
> negotiated operations.

Didn't know that either.  Thank you.


>> Any suggestions for how I might go about determining the cause of
>> client disconnects not getting detected?
>
> I suggest you turn off any frewalls that are between the client and
> server, and use an external packet sniffer to watch the TCP traffic to
> ensure everythng is being transmitted properly.

There probably are not any firewalls between the client and the server, but 
it is possible -- I'll have to pass that question along to the customer.  I 
have no access to any of my customers' systems as they have very tight 
security and legal restrictions they must adhere to.  Therefore, running a 
packet sniffer is definitely out of the question, not to mention that they 
are probably on the other side of the country, which makes it impossible for 
me to do anything directly.  So I'm going to have to resolve this on my end.

Thanks for the feedback and the ReadFromStack tip.  I'm sure it will come in 
handy.

- Dennis