[X2Go-User] [X2Go-Dev] Bug#471: Bug#471: ATTENTION @Mike#1 - serious bug in x2goserver upgrade script (debian wheezy+squeeze)

[Holger Krause]

Hi Stefan,

Am Donnerstag, 3. April 2014 schrieb Stefan Baur:
> Further Info:
> 
> 1) I'm guessing it's a race condition, with two instances of
> x2gocleansessions running simpultaneously and locking each other up:
> 
> e.g. sample output:
> 
> ps ax|grep clean
>  1995 ?        S      0:36 /usr/bin/perl /usr/sbin/x2gocleansessions
> 16142 pts/0    S+     0:05 /usr/bin/perl /usr/sbin/x2gocleansessions

I found a stale dpkg process on two machines running debian wheezy, but 
couldn't see two x2gocleansessions scripts being executed. Doesn't that speak 
against the hypotheses of a race condition?

> 2) The kill command given below in my previous e-mail doesn't work.
> What worked was this:
> 
> ps ax | grep x2gocleansessions | grep perl \
> 
> | awk ' { print $1 }' | xargs -n 1 kill

that awk pipeline looks a bit complicated to me. Wouldn't

kill $(pidof -x x2gocleansessions)

suffice? I guess, the command you proposed originally doesn't find any 
processes, as x2gocleansessions is a script file interpreted by perl. Option 
'x' seems to let pidof consider also perl processes executing the 
x2gocleansessions script. Perhaps this is also helpfull for Buddy? For me, it 
worked (despite having only one x2gocleansessions script stuck).

Cheers,

Holger

> >  4962 pts/1    Z+     0:00 [x2goserver.post] <defunct>
> >  5004 pts/1    S+     0:00 /usr/bin/perl /usr/sbin/x2gocleansessions
> > 
> > manually killing x2gocleansessions (" kill $(pidof x2gocleansessions)")
> > seems to be a workaround, but still, we need a real fix in the form of