slow ssh editing on LAN [SOLVED]

[bittwister]

Anyone else with the problem of slow response editing a file across the LAN using ssh.?

example:
ssh another_lan_node_here
kwrite .bashrc

Clicking at bottom of file takes about ~6 seconds for the cursor to start blinking where I have placed the mouse.
Same delay when using down arrow.

Does not matter if I use node or ip address on ssh.
fconfig shows no errors

Code: Select all

$ ifconfig | grep error
        RX errors 0  dropped 0  overruns 0  frame 0
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Code: Select all

#  mii-tool enp4s0
enp4s0: negotiated 100baseTx-FD flow-control, link ok

Same values on target node. No journalctl messages when running the tests.
Same problem for mga4 & 5 on my installs. System is not busy

Code: Select all

$ htop
  1  [#*                        2.9%]     Tasks: 179, 217 thr; 1 running
  2  [                          0.0%]     Load average: 0.13 0.12 0.13
  3  [#*                        1.4%]     Uptime: 12:35:08
  4  [#                         1.4%]
  Mem[||||||#************1533/7986MB]
  Swp[|                     0/7999MB]

  PID USER      PRI  NI  VIRT   RES   SHR S CPU% MEM%   TIME+  Command         
 7344 browser    20   0 1015M  188M 72756 S  4.7  2.4  1:51.54 firefox /accounts
 2663 root       20   0  294M  122M 90732 S  0.9  1.5  7:51.24 /etc/X11/X :0 vt1
 7368 browser    20   0 1015M  188M 72756 S  0.5  2.4  0:08.15 firefox /accounts
 5054 bittwiste  20   0 2662M 90832 53352 S  0.0  1.1  3:10.97 kwin             
 8586 bittwiste  20   0 19772  3444  2784 R  0.0  0.0  0:00.06 htop             
 5402 bittwiste  20   0  532M 53692 13280 S  0.0  0.7  0:27.51 /usr/sbin/mysqld

[doktor5000]

Do you see the same behaviour when you don't use a graphical editor?
E.g. using vim, or joe, or nano or mcedit or similar instead of kate.

[jiml8]

I occasionally observe very long delays (upwards of 10 seconds) between issuing the ssh command and getting a response requesting password. I notice these delays intermittently irrespective of the distro on which I type the command or the distro to which I am connecting, including all possible combinations of Mageia, OpenSUSE, Ubuntu, FreeBSD 6, FreeBSD 8, FreeBSD 9, and FreeBSD 10, using both openssh and dropbear, over both a LAN or a WAN, including servers installed on bare metal and virtual machines.

Why it happens, I cannot say. Why it only happens sometimes...I don't know.

However, once the connection is established, and presuming X forwarding is properly configured (for those servers that have X available), I never notice any delays that can be associated with anything other than network latencies, network loads, and server loads. If you are having this kind of problem, I suggest you look at these things.

[bittwister]

I occasionally observe very long delays (upwards of 10 seconds) between issuing the ssh command and getting a response requesting password.

Not seeing your delays. I can ssh into either my testbed (tb) or mythtv (mtv) nodes run xterm or xeyes and response to activation of ssh, xterm, xeyes is less or not quite 1 second. I can not see any mouse movement delays.

[bittwister]

Do you see the same behaviour when you don't use a graphical editor?
E.g. using vim, or joe, or nano or mcedit or similar instead of kate.

Just tried emacs and response was as responsive as running locally.

I would like anyone who has a multi node setup to test kwrite over ssh to another node just to test if it is a system problem or something I have done to my system. I can not recreate the problem in VirtualBox guest to host.

[jiml8]

Just tried emacs and response was as responsive as running locally.

I would like anyone who has a multi node setup to test kwrite over ssh to another node just to test if it is a system problem or something I have done to my system. I can not recreate the problem in VirtualBox guest to host.

I just tried that from a Mageia 4 system to another Mageia 4 system on a different subnet, connecting via ssh through a router. Worked fine; connection was fast enough it appeared to be local.

[bittwister]

I just tried that from a Mageia 4 system to another Mageia 4 system on a different subnet, connecting via ssh through a router. Worked fine; connection was fast enough it appeared to be local.

Thank you for your time, I was afraid the problem was local to my setup. I had the problem on Mageia 4 but it was easy enough to hit the desktop switcher button to jump to the desired system. With Maggeia 5 it has become worse enough to impact MythTv Frontend audio and mythtv-setup.

[bittwister]

Anyone else with the problem of slow response editing a file across the LAN using ssh.?

example:
ssh another_lan_node_here
kwrite .bashrc

Solution: replaced switch. Pretty sad that none of the interfaces showed any errors.

[doktor5000]

Next time you could run iperf/jperf and watch for jitter and other errors between those hosts, just a hint.