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Forum Topic - TCP/IP questions: (4 Items)
   
Update
Mitchell Schoenbrun
07/23/2010 7:32 PM
post60498
TCP/IP questions   
Two TCP/IP questions

1) I'm running a test with one server and multiple clients.   At between 90 and 100 clients something happens and my 
code locks up.   I know it's not threads, fd's, or socket's.   Any obvious limit I'm hitting?

2) I'm having trouble bringing down a listening socket gracefully.   If I just break the program, or if I do a 
shutdown()/close() on the socket, the socket continues to appear for about a minute with "netstat -a".   While it's 
still there if I re-start the server program it crashes, though that's probably my codes problem.   Anyone know the 
right way to bring the socket down and have it disappear immediately?

Thank you,
Mitchell Schoenbrun
07/26/2010 5:41 PM
post60666
Re: TCP/IP questions   
I now have a more clear picture of the connection problem.

If I run a server and try to attach 100 clients, it locks up.   If I run a server with 90 clients, it works fine.   If I
 then start a 2nd server on another port and try to start clients, about 10 start up before everything locks up.   

After killing all the processes and waiting for the connections to time out, all seems back to normal.

This suggests a built in limitation in io-net or io-pkg (I've tried both using 6.3.2 and 6.4) or the tcpip protocol 
module.

I looked in the docs and could not find any mentioned limitation nor any parameter to increase the number of connections
.  

This is not currently holding anything up, however my customer is very concerned about this as a roadblock to future 
expansion of the system we are developing.

I would appreciate hearing whether there is any known reason for this behavior.

Thank you
Sean Boudreau(deleted)
07/26/2010 6:44 PM
post60680
RE: TCP/IP questions   
Is there anything in the sloginfo on 6.4?

-seanb

-----Original Message-----
From: Mitchell Schoenbrun [mailto:community-noreply@qnx.com]
Sent: Mon 7/26/2010 5:41 PM
To: technology-networking
Subject: Re: TCP/IP questions
 
I now have a more clear picture of the connection problem.

If I run a server and try to attach 100 clients, it locks up.   If I run a server with 90 clients, it works fine.   If I
 then start a 2nd server on another port and try to start clients, about 10 start up before everything locks up.   

After killing all the processes and waiting for the connections to time out, all seems back to normal.

This suggests a built in limitation in io-net or io-pkg (I've tried both using 6.3.2 and 6.4) or the tcpip protocol 
module.

I looked in the docs and could not find any mentioned limitation nor any parameter to increase the number of connections
.  

This is not currently holding anything up, however my customer is very concerned about this as a roadblock to future 
expansion of the system we are developing.

I would appreciate hearing whether there is any known reason for this behavior.

Thank you



_______________________________________________

Technology
http://community.qnx.com/sf/go/post60666
Attachment: Text winmail.dat 2.99 KB
Mitchell Schoenbrun
07/26/2010 7:33 PM
post60684
Re: RE: TCP/IP questions   
# sloginfo
Time             Sev Major Minor Args
Jul 26 15:12:07    3    14     0 Threads exhausted.  See "threads_max" option

Now why don't I think of this sort of thing more often.
That was the problem.
I increased threads_max and the problem went away.

Thanks,

Mitchell

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