[lttng-dev] LTTng 2.1: create session errors

[David Goulet]

Just in time before I push for 2.1 sable.

Bernd Hufmann:
> Hello
> 
> I'm currently using lttng-tools 2.1.0-RC9. I see some errors when using
> "lttng create " with streaming options:
> 
> 1) lttng create mysession -C net://192:1.1.1: -D net://192:1.1.1.1
> 
> The command output shows:
>    Session mysession created.
>    Traces will be written in (null)
>    Control URL net://192.1.1.1.1 set for session mysession
>    Data URL net://192.1.1.1.1 set for session mysession
> 
> The line "Traces will be written in (null)" should show the correct
> location similar when using the -U option. Also, when typing "lttng list
> mysession" afterwards the trace path is not displayed correctly.
> (mysession (net://192.1.1.1:5342/ [data: 5343]) [inactive]).

Fixed.

> 
> 2) lttng create mysession -C net://192:1.1.1:5342 -D net://192.1.1.1:5343
> 
> This command output shows:
>    Session mysession created.
>    Traces will be written in (null)
>    Error: Control URL uses the net:// protocol and the data URL is
> different. Not allowed.
>    Error: Invalid parameter
> 
> The command fails with an error. However, the session seems to be
> created, but no consumer is defined. First of all, it should be possible
> to define the port with the option -C and -D. Secondly, if an error
> occurs the session shouldn't be created.

Both URL are not equal since the port is different here. So, you CAN'T
use net:// with create session unless both URLs are identical. Use
tcp:// here. The net:// protocol stands for the default transport layer
for both port.

The session stays created here and I can't change that for now. You can
simply use "lttng enable-consumer" after to set the correct thing. This
could however be changed for next version as a bug fix.

> 
> 3) lttng create mysession -C net://192.1.1.1
> 
> This command doesn't fail. I expected it to fail since the command help
> states that -D <data URL> must be used too. BTW, "lttng create mysession
> -D net://192.1.1.1" fails.

Fixed.

> 
> 4) lttng create mysession -C net://192:1.1.1 -D net://192.1.1.2
> This command fails, because the IP address is not the same. Is this
> intended?

It is because URLs are not identical. Use tcp:// here instread.

> 
> 5) In "lttng create -h" and "enable-consumer -h" show "tcp[4|6]" as
> possible protocols, but "tcp4" doesn't work. I have to use "tcp". The
> help should be updated for that.

Fixed

> 
> 6) Why isn't it possible to use "tcp[6]" together with option -U?
> Instead "net[6]" has to be used, which defaults to TCP as network
> transport.

-U is used to specify BOTH url for ports so for now we only allow net://
that do this job.

Future work will fine grained more the URI parsing but for now, use
net[6]:// only with -U.

It will be upstream in a jiffy.

Thanks!
David

> 
> Could someone please look into this?
> 
> Best Regards
> Bernd
> 
> 
>