Forum: Ruby Net::SSH performance question.

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knohr (Guest)
on 2007-05-07 23:18
(Received via mailing list)
I am using Net::SSH to execute scripts on a remote server.  The script
that it executes takes a long time to complete, and dumps allot of
stuff to stdout.  If i allow the script to run as is, this causes ruby
(on the local machine) to eat up massive amounts of cycles, as it
parses the stdout.  Redirecting the stdout to /dev/null on the remote
box will fix the performance issue, but will cause me to lose my SSH
session due to inactivity.

Is there is a way to optimize the following code, (maybe having STDOUT
have a low buffer size)?
keep in mind:
A: i need ssh session to be persistent
B: i cannot modify the settings on the server
C: i really don't want to rewrite the perl script *~2000 lines*
D: i would prefer that the script does not move past the shell.perl
line until the script has completed on the remote box.


Net::SSH.start('foo', :username=>'bar', :password=>'') do |session|
copy_file(session, '/tmp/file')
shell = session.shell.sync
shell.mv ("/tmp/file .")
shell.perl "test"
puts "done"
end
Robert D. (Guest)
on 2007-05-08 01:49
(Received via mailing list)
On 5/7/07, knohr <removed_email_address@domain.invalid> wrote:
> keep in mind:
> shell.mv ("/tmp/file .")
> shell.perl "test"
> puts "done"
> end
>
Hmm there is one question I would have? What do you need as
result/output, if I understood correctly nothing?
In that case maybe not using shell should help, the following works
perfectly on my box

Net::SSH.start( 'localhost' ) do |session|
  session.open_channel do | channel |
    channel.on_data do | ch, data |
      puts data
    end
    channel.exec "find /home/robert -exec ls -ltr {} \\; >/dev/null"
  end
  session.loop
end

It waits until the channel is closed.

HTH
Robert
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