Rootssh is really slow to start up

Newbie
1

ROOT Version: 6.40.04 (conda-forge/linux-64::root-6.40.04-py314h3550fcc_1)
Platform: Ubuntu (WSL 2.0)
Compiler: Not Provided

I’m running ROOT from conda on WSL Ubuntu. I would like to use the interactive browser to look through ROOT files on a remote node. It’s my understanding that the officially supported method for this is via the rootssh script.

(As an aside, I can’t find any “official” documentation saying this. ROOT instructs me to Find more info on https://root.cern/for_developers/root7/#rbrowser, which leads to a 404, but the page exists on archive.org.)

For some reason it takes 2.5 minutes for the rootssh script to complete and remote in.

I timed the login process with

echo "local  $(date --iso-8601=seconds)" \
  && rootssh -v lxplus.cern.ch 'echo remote $(date --iso-8601=seconds)' \
  && echo "local  $(date --iso-8601=seconds)"

Based on the verbose ssh output and the timing of the Use local port ... echo statement in rootssh, almost all of the time is spent earlier in the actual rootssh script and not in ssh itself, which only takes a few seconds; if I replace rootssh with ssh the whole thing executes in 2 seconds.

Am I missing an argument or something? I looked at the rootssh script itself (cat $(which rootssh)) and I don’t see an obvious reason why it would take so long to execute.

I’m going to try inserting some debug statements into the script to see what’s taking so long here…

2

Hi,

The only chance to understand that happens with rootssh - is trying to debug it.

You can copy it to any local directory and add debug output (like echo "something") in different places. It can be nc process (see around line 54) which listen on special socket receiving commands from remote root process. Or it can be probing of available http port on local machine (see line 162). In last case you can select preferable http port to prevent such probing. Like:

[shell] ./rootssh --port 7788 user@remote.host

Just try and probably you will be able find hanging part.

Regards,
Sergey