LTTng » LTTng-tools

Hi David,

We have observed the following but not sure whether it has been intentionally done that way or not:
We see that there are 2 different ways to start a session using streaming:

From target node:
     lttng-relayd  -C tcp://0.0.0.0:53000 -D tcp://0.0.0.0:53001  -o /cluster/temp/log/temp &

From Local node:
Option-1:
lttng create option1
lttng enable-event -u ust_tests_demo2:loop
lttng enable-consumer -u -s option1 -C tcp://192.168.0.1:53000 -D tcp://192.168.0.1:53001 -e
netstat -etan |egrep '53000|53001' > get 2 ports
lttng start;
netstat -etan |egrep '53000|53001' > get 2 new ports > total of 4 ports
./demo-trace
lttng stop

Option-2:
     lttng create option2 -U net://192.168.0.1:53000:53001
     lttng enable-event -u ust_tests_demo2:loop
     lttng start
     netstat -etan |egrep '53000|53001'   > get total of 2 ports
     ./demo-trace
     lttng stop

Both options produce the same trace result. However, option2 opens only 2 ports (at lttng start) while option1 opens 4 tcp ports (2 at enable-consumer, and 2 at lttng start).
For option1, we have noticed that the control information and the data information are only sent on the 2 ports opened at "lttng start". We are not sure what the 2 ports (open at enable-consumer) are used for.

Could you take a look and let us know ?

The commit we are using is:
userspace : 1fe734e wfcqueue: clarify locking usage
lttng-ust : 1c7b4a9 Fix: memcpy of string is larger than source
ttng-tools: 4dbc372 ABI with support for compat 32/64 bits
Thanks,
Tan