[lttng-dev] Issues running ust 2.1.0 as non root user

[lttng-dev] Issues running ust 2.1.0 as non root user

[Aaron Spear]

Hi all,

I have LTTng 2.1.0 that I built/installed from source, and it all works fine when I run as root.  So as root I can take kernel traces and also ust traces.  However, when I attempt to run UST as a normal user it seems that there is some issue with the session daemon that I am not quite understanding.  It looks like the permissions are correct on the executables in /usr/local/bin and such.  Here is the error that I see with the verbose flag on (not sure if this helps...)

aspear at aspear-deb64 ~
$ lttng --verbose create mytest
DEBUG3: URI string: file:///home/aspear/lttng-traces/mytest-20130111-093135 [in uri_parse() at uri.c:253]
DEBUG3: URI file destination: /home/aspear/lttng-traces/mytest-20130111-093135 [in uri_parse() at uri.c:290]
DEBUG3: URI dtype: 3, proto: 0, host: , subdir: , ctrl: 0, data: 0 [in uri_parse() at uri.c:467]
DEBUG1: LSM cmd type : 8 [in send_session_msg() at lttng-ctl.c:259]
Session mytest created.
Traces will be written in /home/aspear/lttng-traces/mytest-20130111-093135
DEBUG1: Init config session in /home/aspear [in config_init() at conf.c:294]

aspear at aspear-deb64 ~
$ lttng --verbose enable-event -a -u
DEBUG1: Session name found: mytest [in get_session_name() at utils.c:51]
DEBUG1: LSM cmd type : 6 [in send_session_msg() at lttng-ctl.c:259]
Error: Events: Fatal error of the session daemon (channel channel0, session mytest)
DEBUG1: Clean exit [in clean_exit() at lttng.c:169]

Is there perhaps some other setup step required when you do the install from source that the install does for a normal user?

thanks,
Aaron Spear

[lttng-dev] Issues running ust 2.1.0 as non root user

[David Goulet]

Hi Aaron,

You will have to provide the verbose logs of the session daemon. So,
quite simple, start in an other console the session daemon with your
user like so:

$ lttng-sessiond -vvv --verbose-consumer > /tmp/sessiond.log

And do the "lttng" commands again. It's going to be quite easier to
identify the problem.

A Fatal error of the session daemon, I suspect something is not right
with the installation or you are missing memory which I doubt :).

Thanks!
David

Aaron Spear:
> Hi all,
> 
> I have LTTng 2.1.0 that I built/installed from source, and it all works fine when I run as root.  So as root I can take kernel traces and also ust traces.  However, when I attempt to run UST as a normal user it seems that there is some issue with the session daemon that I am not quite understanding.  It looks like the permissions are correct on the executables in /usr/local/bin and such.  Here is the error that I see with the verbose flag on (not sure if this helps...)
> 
> aspear at aspear-deb64 ~
> $ lttng --verbose create mytest
> DEBUG3: URI string: file:///home/aspear/lttng-traces/mytest-20130111-093135 [in uri_parse() at uri.c:253]
> DEBUG3: URI file destination: /home/aspear/lttng-traces/mytest-20130111-093135 [in uri_parse() at uri.c:290]
> DEBUG3: URI dtype: 3, proto: 0, host: , subdir: , ctrl: 0, data: 0 [in uri_parse() at uri.c:467]
> DEBUG1: LSM cmd type : 8 [in send_session_msg() at lttng-ctl.c:259]
> Session mytest created.
> Traces will be written in /home/aspear/lttng-traces/mytest-20130111-093135
> DEBUG1: Init config session in /home/aspear [in config_init() at conf.c:294]
> 
> aspear at aspear-deb64 ~
> $ lttng --verbose enable-event -a -u
> DEBUG1: Session name found: mytest [in get_session_name() at utils.c:51]
> DEBUG1: LSM cmd type : 6 [in send_session_msg() at lttng-ctl.c:259]
> Error: Events: Fatal error of the session daemon (channel channel0, session mytest)
> DEBUG1: Clean exit [in clean_exit() at lttng.c:169]
> 
> Is there perhaps some other setup step required when you do the install from source that the install does for a normal user?
> 
> thanks,
> Aaron Spear
> 
> _______________________________________________
> lttng-dev mailing list
> lttng-dev at lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

[lttng-dev] Issues running ust 2.1.0 as non root user

[Aaron Spear]

Hi David,

----- Original Message -----
> From: "David Goulet" <dgoulet@efficios.com>

> Hi Aaron,
> 
> You will have to provide the verbose logs of the session daemon. So,
> quite simple, start in an other console the session daemon with your
> user like so:
> 
> $ lttng-sessiond -vvv --verbose-consumer > /tmp/sessiond.log
> 
> And do the "lttng" commands again. It's going to be quite easier to
> identify the problem.
> 
> A Fatal error of the session daemon, I suspect something is not right
> with the installation or you are missing memory which I doubt :).
> 
> Thanks!
> David

Thanks very much for the tip, it led me to the solution and it works now.  It would appear that the issue was that there was already some daemon running on the port perhaps in some zombie state or something. I guess maybe they were left there from some earlier failed attempt or something.  I killed these processes and started it up all over and it worked.

I guess the moral of the story is that if this happens at all with some frequency perhaps a little better error message from lttng enable-event would be nice...

here is the error message that I saw when I manually tried to start the sessiond like you instructed:
$ lttng-sessiond -vvv --verbose-consumer > /tmp/sessiond.log
DEBUG3: Creating LTTng run directory: /home/aspear/.lttng [in create_lttng_rundir() at main.c:3692]
DEBUG1: Client socket path /home/aspear/.lttng/client-lttng-sessiond [in main() at main.c:3995]
DEBUG1: Application socket path /home/aspear/.lttng/apps-lttng-sessiond [in main() at main.c:3996]
DEBUG1: LTTng run directory path: /home/aspear/.lttng [in main() at main.c:3997]
DEBUG2: UST consumer 32 bits err path: /home/aspear/.lttng/ustconsumerd32/error [in main() at main.c:4006]
DEBUG2: UST consumer 32 bits cmd path: /home/aspear/.lttng/ustconsumerd32/command [in main() at main.c:4008]
DEBUG2: UST consumer 64 bits err path: /home/aspear/.lttng/ustconsumerd64/error [in main() at main.c:4017]
DEBUG2: UST consumer 64 bits cmd path: /home/aspear/.lttng/ustconsumerd64/command [in main() at main.c:4019]
Error: Already running daemon.

and then this is what I saw when I tried to figure out what daemon was already running:
root at aspear-deb64 ~/lttng-traces
# ps -A | grep ltt
 5024 pts/1    00:00:00 lttng-sessiond
 5110 pts/1    00:00:07 lttng-consumerd
20660 pts/1    00:00:00 lttng-consumerd
25600 ?        00:00:32 lttng-sessiond
25611 ?        00:00:00 lttng-consumerd

thanks again,
Aaron