X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=2.8%2Flttng-docs-2.8.txt;h=e38cafe2c6aa5d4534058788303269b4c659ec8b;hb=664335c3473a73a5164ed35e107163999a7ac933;hp=5a42c473c158eb31ef8595192776abfa04651542;hpb=2e333859971dee32131788543efc1261aebf6f14;p=lttng-docs.git diff --git a/2.8/lttng-docs-2.8.txt b/2.8/lttng-docs-2.8.txt index 5a42c47..e38cafe 100644 --- a/2.8/lttng-docs-2.8.txt +++ b/2.8/lttng-docs-2.8.txt @@ -1,7 +1,7 @@ The LTTng Documentation ======================= Philippe Proulx -v2.8, 2 December 2016 +v2.8, 8 December 2016 include::../common/copyright.txt[] @@ -74,6 +74,15 @@ include::../common/acknowledgements.txt[] [[whats-new]] == What's new in LTTng {revision}? +LTTng{nbsp}{revision} bears the name _Isseki Nicho_. The result of a +collaboration between http://www.dieuduciel.com/[Dieu du Ciel!] and +Nagano-based Shiga Kogen, +https://www.beeradvocate.com/beer/profile/1141/53111/[_**Isseki +Nicho**_] is a strong Imperial Dark Saison offering a rich roasted malt +flavor combined with a complex fruity finish typical of Saison yeasts. + +New features and changes in LTTng{nbsp}{revision}: + * **Tracing control**: ** You can attach <> to a <> with the @@ -864,12 +873,13 @@ The following command lines start with cmd:sudo because you need root privileges to trace the Linux kernel. You can avoid using cmd:sudo if your Unix user is a member of the <>. -. Create a <>: +. Create a <> which writes its traces + to dir:{/tmp/my-kernel-trace}: + -- [role="term"] ---- -sudo lttng create my-kernel-session +sudo lttng create my-kernel-session --output=/tmp/my-kernel-trace ---- -- @@ -879,20 +889,23 @@ sudo lttng create my-kernel-session [role="term"] ---- lttng list --kernel +lttng list --kernel --syscall ---- -- -. Create an <> which matches the desired event names, - for example `sched_switch` and `sched_process_fork`: +. Create <> which match the desired instrumentation + point names, for example the `sched_switch` and `sched_process_fork` + tracepoints, and the man:open(2) and man:close(2) system calls: + -- [role="term"] ---- sudo lttng enable-event --kernel sched_switch,sched_process_fork +sudo lttng enable-event --kernel --syscall open,close ---- -- + -You can also create an event rule which _matches_ all the Linux kernel +You can also create an event rule which matches _all_ the Linux kernel tracepoints (this will generate a lot of data when tracing): + -- @@ -902,7 +915,7 @@ sudo lttng enable-event --kernel --all ---- -- -. Start tracing: +. <>: + -- [role="term"] @@ -913,7 +926,8 @@ sudo lttng start . Do some operation on your system for a few seconds. For example, load a website, or list the files of a directory. -. Stop tracing and destroy the tracing session: +. <> and destroy the + tracing session: + -- [role="term"] @@ -926,10 +940,15 @@ sudo lttng destroy The man:lttng-destroy(1) command does not destroy the trace data; it only destroys the state of the tracing session. -By default, LTTng saves the traces in -+$LTTNG_HOME/lttng-traces/__name__-__date__-__time__+, -where +__name__+ is the tracing session name. Note that the -env:LTTNG_HOME environment variable defaults to `$HOME` if not set. +. For the sake of this example, make the recorded trace accessible to + the non-root users: ++ +-- +[role="term"] +---- +sudo chown -R $(whoami) /tmp/my-kernel-trace +---- +-- See <> to view the recorded events. @@ -1141,7 +1160,7 @@ lttng enable-event --userspace hello_world:my_first_tracepoint ---- -- -. Start tracing: +. <>: + -- [role="term"] @@ -1152,7 +1171,8 @@ lttng start . Go back to the running `hello` application and press Enter. The program executes all `tracepoint()` instrumentation points and exits. -. Stop tracing and destroy the tracing session: +. <> and destroy the + tracing session: + -- [role="term"] @@ -1167,7 +1187,7 @@ only destroys the state of the tracing session. By default, LTTng saves the traces in +$LTTNG_HOME/lttng-traces/__name__-__date__-__time__+, -where +__name__+ is the tracing session name. Note that the +where +__name__+ is the tracing session name. The env:LTTNG_HOME environment variable defaults to `$HOME` if not set. See <> generated by a Java +application using `java.util.logging` is named `lttng_jul:event` and +has the following fields: + +`msg`:: + Log record's message. + +`logger_name`:: + Logger name. + +`class_name`:: + Name of the class in which the log statement was executed. + +`method_name`:: + Name of the method in which the log statement was executed. + +`long_millis`:: + Logging time (timestamp in milliseconds). + +`int_loglevel`:: + Log level integer value. + +`int_threadid`:: + ID of the thread in which the log statement was executed. + You can use the opt:lttng-enable-event(1):--loglevel or opt:lttng-enable-event(1):--loglevel-only option of the man:lttng-enable-event(1) command to target a range of JUL log levels @@ -4714,6 +4761,37 @@ lttng view ---- ==== +In the resulting trace, an <> generated by a Java +application using log4j is named `lttng_log4j:event` and +has the following fields: + +`msg`:: + Log record's message. + +`logger_name`:: + Logger name. + +`class_name`:: + Name of the class in which the log statement was executed. + +`method_name`:: + Name of the method in which the log statement was executed. + +`filename`:: + Name of the file in which the executed log statement is located. + +`line_number`:: + Line number at which the log statement was executed. + +`timestamp`:: + Logging timestamp. + +`int_loglevel`:: + Log level integer value. + +`thread_name`:: + Name of the Java thread in which the log statement was executed. + You can use the opt:lttng-enable-event(1):--loglevel or opt:lttng-enable-event(1):--loglevel-only option of the man:lttng-enable-event(1) command to target a range of Apache log4j log levels @@ -5033,6 +5111,33 @@ lttng view ---- ==== +In the resulting trace, an <> generated by a Python +application is named `lttng_python:event` and has the following fields: + +`asctime`:: + Logging time (string). + +`msg`:: + Log record's message. + +`logger_name`:: + Logger name. + +`funcName`:: + Name of the function in which the log statement was executed. + +`lineno`:: + Line number at which the log statement was executed. + +`int_loglevel`:: + Log level integer value. + +`thread`:: + ID of the Python thread in which the log statement was executed. + +`threadName`:: + Name of the Python thread in which the log statement was executed. + You can use the opt:lttng-enable-event(1):--loglevel or opt:lttng-enable-event(1):--loglevel-only option of the man:lttng-enable-event(1) command to target a range of Python log levels @@ -5618,7 +5723,7 @@ To output LTTng traces to a non-default location: -- [role="term"] ---- -lttng create --output=/tmp/some-directory my-session +lttng create my-session --output=/tmp/some-directory ---- -- @@ -6549,7 +6654,7 @@ To use LTTng live: -- [role="term"] ---- -lttng create --live my-session +lttng create my-session --live ---- -- + @@ -6616,7 +6721,7 @@ To take a snapshot: -- [role="term"] ---- -lttng create --snapshot my-session +lttng create my-session --snapshot ---- -- + @@ -6759,7 +6864,7 @@ trace data after a system crash: -- [role="term"] ---- -lttng create --shm-path=/path/to/shm +lttng create my-session --shm-path=/path/to/shm ---- --