[JSch-users] Number of exec channels with pty

[Daniel F. F. <dan...@te...>]

Hi people,

I have experienced  problems in opening several concurrent exec channels with 
pty.

In my application, after connecting to the remote host, I create several 
concurrent exec channels, to run different programs on the remote host ant 
the same time and through the same connection. Some of the exec channels 
require pty, some do not. 

The advantage is that creating an exec channel is much faster then opening a 
new connection.

I noticed that after I have created the 8th exec channel with pty, any further 
attempt to run an application on new exec channel fails silently and gives 
return value 1. After I have closed one of the 8 channels with pty, I can 
create new exec channels again.

Notice that the computer has plenty of free ptys available, the limitantion is 
caused by the ssh connection.

Did someone notice this problem?

This was noticed on the majority of openssh servers, but some openssh servers 
do not have this limitation. But the is no opetion in openssh server to limit 
the number of exec channels, nor the number of ptys.

Best regards,
Daniel Felix Ferber