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Alex Liu · Guest

I am not sure if this is the right place for my question. Pls help/forgive
me if i post it wrong.

i have two server side applications, A and B, which use TServerSocket in
blocking mode for communicating with clients. The server socket threads will
perform both read and write operations. In my case the two servers and just
sending heartbeat only.

A client application connects to the 2 servers via Intranet (in office).
This case all are working fine.

Now the whole system is put to a higher explosure level by setting up of
VPN. Home users first connects to Internet, then connects to the office by
NetScreen (a H/W + S/W 3rd party package) which provides SSL encryption over
the connection. After VPN has established the user is able to run my client
application.

However, server A, under this situation, will crash (just simply
disappeared) while B still works fine.
The time of crash after client has connected varies from serveral minutes to
an hour.

I added logs in A and found that there seems to be a disconnection (maybe
because of Internet connection) so the client should be disconnected from A
before crash. And, AFTER 20 SECONDS, another disconnection event occur which
has no identity. This is the last log i got before crash.
The log i applied is simply adding log message to log file recording
incoming IP and socket handle which is recorded in dtor() of the socket
thread. The result shows that the IP is empty and no socket handle. This
means no ctor() is called beforehand. I dont know why an extra disconnection
is taking place.

sample log:
15:00:00.000 disconnect IP=123.123.123.1 socket handle=222
..... // other log
15:00:20.213 disconnect IP= socket handle= // ???

an extra info but i dont know whether it helps:
My user found that when another Intranet user is connecting and turned the
machine (MS Window) to sleep mode, the crash will take place otherwise there
is no problem. Technically speaking I think there should be no relation but
it really seems so.

I am not sure if i provide enough information or ...... I dont know.

Please kindly advice.