gruis
em-ssh-shell fails to start shell without error
Not sure whats happening yet, but my block inside EM::Ssh::Shell.new never gets evaluated, and no errors are raised
I can simulate this easily by connecting 50 times concurrently
Can you post some example code please?
Sent from my iPhone
On 2012/04/24, at 19:18, Mark [email protected] wrote:
Not sure whats happening yet, but my block inside EM::Ssh::Shell.new never gets evaluated, and no errors are raised
I can simulate this easily by connecting 50 times concurrently
Reply to this email directly or view it on GitHub: https://github.com/simulacre/em-ssh/issues/5
EM.run {
EM.error_handler do |e|
puts " **** ERROR #{e.message}"
puts e.backtrace.join "\n"
end
started=0
(1..30).each do
EM::Ssh::Shell.new("localhost", "emtest", "emdemo") do |shell|
started+=1
shell.on(:error) do |e|
puts "Shell error :( #{e}"
end
shell.on(:closed) do |e|
puts "Shell close :( #{e}"
end
end
end
EventMachine::PeriodicTimer.new(1) do
puts "We have #{started} connections"
end
}
On my machine stared goes to 10, but never get any exceptions or errors.
I found the reason for the 10 limit is the sshd_config default for MaxStartups is 10 but it doesn't explain the lack of errors.
I'd put my money on this actually being the thread pool in EM (I believe it defaults to 20)...
Also, opening 30+ requests is quite inefficient, I'd suggest looking into using EM's work and request pooling:
https://github.com/eventmachine/eventmachine/blob/master/lib/em/pool.rb#L9-38
root 2106 1 0 Aug13 ? 00:00:28 /usr/sbin/sshd root 19326 2106 0 11:02 ? 00:00:00 sshd: root@pts/0 root 24137 2106 0 18:01 ? 00:00:00 sshd: root@pts/1 root 24154 2106 0 18:01 ? 00:00:00 sshd: root@pts/2 root 24155 2106 0 18:01 ? 00:00:00 sshd: root@pts/3 root 24156 2106 0 18:01 ? 00:00:00 sshd: root@pts/4 root 24157 2106 0 18:01 ? 00:00:00 sshd: root@pts/5 root 24158 2106 0 18:01 ? 00:00:00 sshd: root@pts/6 root 24159 2106 0 18:01 ? 00:00:00 sshd: root@pts/7 root 24160 2106 0 18:01 ? 00:00:00 sshd: root@pts/9 root 24161 2106 0 18:01 ? 00:00:00 sshd: root@pts/8 root 24162 2106 0 18:01 ? 00:00:00 sshd: root@pts/10 root 24163 2106 0 18:01 ? 00:00:00 sshd: root@pts/11 root 24305 24139 0 18:01 pts/1 00:00:00 grep ssh [root ~]# ps -ef | grep ssh root 2106 1 0 Aug13 ? 00:00:28 /usr/sbin/sshd root 19326 2106 0 11:02 ? 00:00:00 sshd: root@pts/0 root 24137 2106 0 18:01 ? 00:00:00 sshd: root@pts/1 root 24307 24139 0 18:01 pts/1 00:00:00 grep ssh
I was incorrect. Tested the pool, not the case.
It's the max_startups as described above.
However, this still should be handled in a work queue, 10 simultaneous connections is plenty.
