[lxc-users] LXC leaking ptys?

[Harald Dunkel]

On 07/15/14 16:24, Serge Hallyn wrote:
> Quoting Harald Dunkel (harald.dunkel at aixigo.de):
>>
>> Nothing unusual. The log files show a lot of ssh sessions run by
>> our monitoring software (active just for a few milliseconds), plus
>> my own ssh sessions for maintenance. Thats all.
> 
> Ah, interesting.  That could be fun to try to reproduce.  But I
> would expect that to be transient, so that the monitoring software
> could just retry, by which point the other very-short connections
> should be closed and new connections should succeed...
> 

To give you more information about these high-frequency ssh sessions:
Every 5 minutes I check the status of the LXC clients, using something
like
	ssh $server test -d /cgroup/lxc/$client && echo "${server}:${client} OK"

There are 4 ssh jobs per client, i.e. I get about 120 ssh sessions
within a few seconds. Then its silent for the next 5 minutes. Important
is that these ssh sessions don't need a pty. They succeed, even when
an interactive ssh session would report "stdin: not a tty". Surely
they do not overlap each other.

I have reduced this to run a test every 30 minutes now, but actually I
do not see a problem with this. I monitor all my LXC and KVM servers
using this script. Only interactive sessions on the server are affected.


Regards
Harri