The session daemon, acting as a tracing registry, allow you to interact with
multiple tracers (kernel and user-space) inside the same container, a tracing
session. Trace can be gathered from the kernel and/or instrumented applications
-(lttng-ust(3)). Aggregating those traces is done using a viewer, like the
+(lttng-ust(3)). Aggregating those traces is done using a viewer, like the
babeltrace(1) text viewer.
In order to trace the kernel, the session daemon needs to be running as root.
.IP "LTTNG_DEBUG_NOCLONE"
Debug-mode disabling use of clone/fork. Insecure, but required to allow
debuggers to work with sessiond on some operating systems.
+.IP "LTTNG_APP_SOCKET_TIMEOUT"
+Control the timeout of application's socket when sending and receiving
+commands. After this period of time, the application is unregistered by the
+session daemon. A value of 0 or -1 means an infinite timeout. Default value is
+5 seconds.
.SH "SEE ALSO"
.PP
babeltrace(1), lttng-ust(3), lttng(1)
.PP
+
+.SH "LIMITATIONS"
+
+.PP
+For unprivileged user running lttng-sessiond, the maximum number of file
+descriptors per process is usually 1024. This limits the number of traceable
+applications since for each instrumented application there is two file
+descriptors per-CPU and one more socktet for bidirectional communication.
+
+For the root user, the limit is bumped to 65535. Future version will deal with
+this limitation.
+.PP
+
.SH "BUGS"
.PP
.PP
Thanks to Yannick Brosseau without whom this project would never have been so
-lean and mean! Also thanks to the Ericsson teams working on tracing which
-helped us greatly with detailed bug reports and unusual test cases.
+lean and mean! Also thanks to the Ericsson teams working on tracing which helped
+us greatly with detailed bug reports and unusual test cases.
Thanks to our beloved packager Alexandre Montplaisir-Goncalves (Ubuntu and PPA
maintainer) and Jon Bernard for our Debian packages.