QNET disconnect causes massive slowdown

QNX Newsgroups (Archives) qdn.public.qnxrtp.os
1

I ran a little test with QNET:

  1. connect two QNX6.1 computers (A and B) both running QNET
  2. allow both to detect each other
  3. pull the network cable out of machine A
  4. on machine B, type “ls /net/A”, causing B to notice that A is not
    running.
  5. plug the network cable back into A
  6. on machine B, type “ls /net/A”, causing A and B to reconnect
  7. copy a 3Meg file from A onto B

I noticed a problem.

  • in step 6, “ls /net/A” was very very slow. Subsequent ls commands
    across the network were no faster.

  • in step 7, the copy operation took 42 minutes!

root@:/home/andrew# ls /net
andrewhome elena

root@:/home/andrew# time cp /net/elena/usr/bin/emacs /tmp
real 42m35.397s
user 0m0.009s
sys 0m0.002s

root@:/home/andrew# ls -l /tmp/emacs
-rwxr-xr-x 1 root root 3144196 Mar 13 11:57 /tmp/emacs

I know this is a bug, but is there anything I can do to mitigate it?

Thanks,
Andrew

Andrew Thomas, President, Cogent Real-Time Systems Inc.
2430 Meadowpine Boulevard, Suite 105, Mississauga, Ontario, Canada L5N 6S2
Email: andrew@cogent.ca WWW: http://www.cogent.ca

2

Hi Andrew,

What network drivers they are using as well as
the output from nicinfo and sloginfo.

Thanks

E.


Andrew Thomas <andrew@cogent.ca> wrote:

I ran a little test with QNET:

  1. connect two QNX6.1 computers (A and B) both running QNET
  2. allow both to detect each other
  3. pull the network cable out of machine A
  4. on machine B, type “ls /net/A”, causing B to notice that A is not
    running.
  5. plug the network cable back into A
  6. on machine B, type “ls /net/A”, causing A and B to reconnect
  7. copy a 3Meg file from A onto B

I noticed a problem.

  • in step 6, “ls /net/A” was very very slow. Subsequent ls commands
    across the network were no faster.

  • in step 7, the copy operation took 42 minutes!

root@:/home/andrew# ls /net
andrewhome elena

root@:/home/andrew# time cp /net/elena/usr/bin/emacs /tmp
real 42m35.397s
user 0m0.009s
sys 0m0.002s

root@:/home/andrew# ls -l /tmp/emacs
-rwxr-xr-x 1 root root 3144196 Mar 13 11:57 /tmp/emacs

I know this is a bug, but is there anything I can do to mitigate it?

Thanks,
Andrew

Andrew Thomas, President, Cogent Real-Time Systems Inc.
2430 Meadowpine Boulevard, Suite 105, Mississauga, Ontario, Canada L5N 6S2
Email: > andrew@cogent.ca > WWW: > http://www.cogent.ca