Re: [SOLVED] Re: webserver stalls [was Re: bug in (linux) slattach]

[Harry Kalogirou <harkal@gmx.net>]

> On 22 Oct 2002, Harry Kalogirou wrote:
> 
> > > Ok the quest is over.
> 
> Not yet. I think _tcp_chksumraw in tcp_output.c needs the same fixes as 
> those you applied to _tcp_chksum. Without them I still got partial files 
> with telnet/get.

It is fixed.
 
> There's *still* something wrong, but it shows up most frequently when I 
> urlget from one ELKS box to another (yes, they have different IP 
> addresses). Rarely, all goes as it should; more often, the entire file 
> comes in a reasonable time, but I never get the command prompt; often, 
> nothing comes in and I never get the command prompt. Once, nothing seemed 
> to happen for about 10 minutes, but when I checked the machines about 10 
> minutes later, the file had come in but there was no command prompt. I had 
> enabled a second getty on that machine, so I was able to log in and run 
> netstat on both machines while urlget was hung. Here are the results 
> (about an hour later):
> 
> On the client ("urlget") machine (192.168.1.100) --
> 1 ESTABLISHED 4000ms 1025       0.0.0.0  2
> 2 ESTABLISHED 2400ms 1024 192.168.1.144 80
> 3      LISTEN 4000MS   80       0.0.0.0  0
> 
> 
> On the server ("sender") (1.2.168.1.144) --
> 1 ESTABLISHED 4000ms 1024       0.0.0.0  2
> 2      LISTEN 4000ms   80       0.0.0.0  0
> 
> Obviously, the server has discarded the connection, but the client machine
> thinks it's still connected.
> 
> I'm also not sure the client port number (the one that's 1024 or greater) 
> is handled properly. Each time I connect from a Linux box the port number 
> is incremented, but once I observered that a first, successful, connection 
> from ELKS was from port 1024, and the next, hanging, attempt was *also* 
> port 1024. Connections from Linux usually, but not always, work; 
> connections from ELKS rarely work.

ELKS reuses the last used port if it is not still in use. I don't think
that this is a problem. 

> Diagnosing this stuff is very time-consuming because "kill" doesn't seem 
> to do anything, so I must reboot both machines. Since ELKS "telnet" 

The kernel in the CVS will probably handle this more gracefully and
actualy the process.

> doesn't do anything but connect (and logs me out when it terminates!) I 
> can't compare telnet from Linux and ELKS. I can only compare "urlget" from 
> both systems, and since there's no tcpdump for ELKS I can't even determing 
> if a failure is actually due to urlget.

You mean that you do "telnet bla.bla 80" and after you connect you can't
do "get /"?

Harry