[X2Go-Dev] Bug#1129: x2gobroker-ssh big delay in session status recovery

[Mike Gabriel]

Dear Miguel,

Package: x2gobroker
Version: 0.0.3.1
When x2gobroker-ssh is used with system with not IPv6 configured,
this generate very big delays in x2gobroker listsession task.
Before some research, the problem become from x2gobroker.utils
portscan function.
This function propagates a delay in all agents call because it tests
/ip_proto = 0////try:////socket.getaddrinfo(addr, None,
socket.AF_INET6)////ip_proto = 6////except
socket.gaierror:////try:////socket.getaddrinfo(addr, None,
socket.AF_INET)////ip_proto = 4////except socket.gaierror:////# we
can't find a valid address for this host, so returning a
failure...////return False /This will be fixed testing IPv4 first or
more easily, setting a new option in config to select the ip protocol.

A while ago you reported the above issue.

I tested this now.

The portscan function in x2gobroker.utils is really fast when
detecting that a remote host is not IPv6 supportive. It basically is a
fast DNS query.

Is it so, that your client system has IPv4 disabled entirely (in the
kernel)? Or what exactly did you mean by "When x2gobroker-ssh is used
with system with not IPv6 configured..."?

I am willing to do more test, please provide more info. You possibly
also have found a fix meanwhile. If so, I'd be happy, if you could
share it.

Thanks
Mike