X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=2.8%2Flttng-docs-2.8.txt;h=a6d160ffd84822acef98e84274bc8430ddbe7b75;hb=46adfb4b867899cd3f05171d0dbce70302022bcc;hp=f17290470b896c8df68742b9dbfe19805ce97baa;hpb=ded026983bfe6b3ba0365bba59c93b4aa55bb37a;p=lttng-docs.git diff --git a/2.8/lttng-docs-2.8.txt b/2.8/lttng-docs-2.8.txt index f172904..a6d160f 100644 --- a/2.8/lttng-docs-2.8.txt +++ b/2.8/lttng-docs-2.8.txt @@ -1,12 +1,15 @@ The LTTng Documentation ======================= Philippe Proulx -v2.8, 20 February 2017 +v2.8, 24 July 2017 include::../common/copyright.txt[] +include::../common/warning-not-maintained.txt[] + + include::../common/welcome.txt[] @@ -357,6 +360,8 @@ becomes inactive or in real-time. [[installing-lttng]] == Installation +include::../common/warning-installation-outdated.txt[] + **LTTng** is a set of software <> which interact to <> the Linux kernel and user applications, and to <> (start and stop @@ -381,7 +386,7 @@ but note that: applications. [role="growable"] -.Availability of LTTng{nbsp}{revision} for major Linux distributions as of 2 December 2016. +.Availability of LTTng{nbsp}{revision} for major Linux distributions as of 14 March 2017. |==== |Distribution |Available in releases |Alternatives @@ -395,6 +400,9 @@ LTTng{nbsp}2.9 for Ubuntu{nbsp}14.04 _Trusty Tahr_ and Ubuntu{nbsp}16.04 _Xenial Xerus_: link:/docs/v2.9#doc-ubuntu-ppa[use the LTTng Stable{nbsp}2.9 PPA]. +LTTng{nbsp}2.9 for Ubuntu{nbsp}17.04 _Zesty Zapus_ (not released +yet). + <> for other Ubuntu releases. @@ -404,9 +412,11 @@ other Ubuntu releases. other Fedora releases. |https://www.debian.org/[Debian] -|<>. -|<> for -previous Debian releases. +|_Not available_ +|link:/docs/v2.9#doc-debian[LTTng{nbsp}2.9 for Debian "stretch" (testing) +and Debian "sid" (unstable)]. + +<>. |https://www.opensuse.org/[openSUSE] |_Not available_ @@ -416,12 +426,13 @@ previous Debian releases. |_Not available_ |link:/docs/v2.9#doc-arch-linux[LTTng{nbsp}2.9 from the AUR]. +<>. + |https://alpinelinux.org/[Alpine Linux] -|<>. -|LTTng{nbsp}{revision} for Alpine Linux{nbsp}3.5 (not released yet). +|_Not available_ +|link:/docs/v2.9#doc-alpine-linux[LTTng{nbsp}2.9 for Alpine Linux "edge"]. -<> for -other Alpine Linux releases. +<>. |https://www.redhat.com/[RHEL] and https://www.suse.com/[SLES] |See http://packages.efficios.com/[EfficiOS Enterprise Packages]. @@ -429,13 +440,18 @@ other Alpine Linux releases. |https://buildroot.org/[Buildroot] |<>. -|<> for +|link:/docs/v2.9#doc-buildroot[LTTng{nbsp}2.9 for Buildroot 2017.02]. + +<> for other Buildroot releases. |http://www.openembedded.org/wiki/Main_Page[OpenEmbedded] and https://www.yoctoproject.org/[Yocto] |<> (`openembedded-core` layer). -|<> for +|LTTng{nbsp}2.9 for Yocto Project{nbsp}2.3 _Pyro_ +(`openembedded-core` layer) (not released yet). + +<> for other OpenEmbedded releases. |==== @@ -575,105 +591,19 @@ sudo depmod -a .Java and Python application instrumentation and tracing ==== If you need to instrument and trace <> on openSUSE, you need to build and install +applications>> on Fedora, you need to build and install LTTng-UST{nbsp}{revision} <> and pass the `--enable-java-agent-jul`, `--enable-java-agent-log4j`, or `--enable-java-agent-all` options to the `configure` script, depending on which Java logging framework you use. If you need to instrument and trace <> on openSUSE, you need to build and install +applications>> on Fedora, you need to build and install LTTng-UST{nbsp}{revision} from source and pass the `--enable-python-agent` option to the `configure` script. ==== -[[debian]] -=== Debian - -To install LTTng{nbsp}{revision} on Debian "stretch" (testing): - -. Install the main LTTng{nbsp}{revision} packages: -+ --- -[role="term"] ----- -# apt-get install lttng-modules-dkms -# apt-get install liblttng-ust-dev -# apt-get install lttng-tools ----- --- - -. **If you need to instrument and trace <>**, install the LTTng-UST Java agent: -+ --- -[role="term"] ----- -# apt-get install liblttng-ust-agent-java ----- --- - -. **If you need to instrument and trace <>**, install the LTTng-UST Python agent: -+ --- -[role="term"] ----- -# apt-get install python3-lttngust ----- --- - - -[[alpine-linux]] -=== Alpine Linux - -To install LTTng-tools{nbsp}{revision} and LTTng-UST{nbsp}{revision} on -Alpine Linux "edge": - -. Make sure your system is - https://wiki.alpinelinux.org/wiki/Edge[configured for "edge"]. -. Enable the _testing_ repository by uncommenting the corresponding - line in path:{/etc/apk/repositories}. -. Add the LTTng packages: -+ --- -[role="term"] ----- -# apk add lttng-tools -# apk add lttng-ust-dev ----- --- - -To install LTTng-modules{nbsp}{revision} (Linux kernel tracing support) -on Alpine Linux "edge": - -. Add the vanilla Linux kernel: -+ --- -[role="term"] ----- -# apk add linux-vanilla linux-vanilla-dev ----- --- - -. Reboot with the vanilla Linux kernel. -. Download, build, and install the latest LTTng-modules{nbsp}{revision}: -+ --- -[role="term"] ----- -$ cd $(mktemp -d) && -wget http://lttng.org/files/lttng-modules/lttng-modules-latest-2.8.tar.bz2 && -tar -xf lttng-modules-latest-2.8.tar.bz2 && -cd lttng-modules-2.8.* && -make && -sudo make modules_install && -sudo depmod -a ----- --- - - [[enterprise-distributions]] === RHEL, SUSE, and other enterprise distributions @@ -733,14 +663,14 @@ If you use Hob: .Java and Python application instrumentation and tracing ==== If you need to instrument and trace <> on openSUSE, you need to build and install +applications>> on Yocto/OpenEmbedded, you need to build and install LTTng-UST{nbsp}{revision} <> and pass the `--enable-java-agent-jul`, `--enable-java-agent-log4j`, or `--enable-java-agent-all` options to the `configure` script, depending on which Java logging framework you use. If you need to instrument and trace <> on openSUSE, you need to build and install +applications>> on Yocto/OpenEmbedded, you need to build and install LTTng-UST{nbsp}{revision} from source and pass the `--enable-python-agent` option to the `configure` script. ==== @@ -1605,10 +1535,14 @@ as soon as a there's no space left for a new event record, whereas in discard mode, the tracer only discards the event record that doesn't fit. -In discard mode, LTTng increments a count of lost event records when -an event record is lost and saves this count to the trace. In -overwrite mode, LTTng keeps no information when it overwrites a -sub-buffer before consuming it. +In discard mode, LTTng increments a count of lost event records when an +event record is lost and saves this count to the trace. In overwrite +mode, since LTTng 2.8, LTTng increments a count of lost sub-buffers when +a sub-buffer is lost and saves this count to the trace. In this mode, +the exact number of lost event records in those lost sub-buffers is not +saved to the trace. Trace analyses can use the trace's saved discarded +event record and sub-buffer counts to decide whether or not to perform +the analyses even if trace data is known to be missing. There are a few ways to decrease your probability of losing event records. @@ -1633,8 +1567,8 @@ to configure the sub-buffer count and size for them: * **High event throughput**: In general, prefer bigger sub-buffers to lower the risk of losing event records. + -Having bigger sub-buffers also ensures a lower sub-buffer switching -frequency. +Having bigger sub-buffers also ensures a lower +<>. + The number of sub-buffers is only meaningful if you create the channel in overwrite mode: in this case, if a sub-buffer overwrite happens, the @@ -1788,7 +1722,7 @@ With so many similar terms, it's easy to get confused. An **event** is the consequence of the execution of an _instrumentation point_, like a tracepoint that you manually place in some source code, or a Linux kernel KProbe. An event is said to _occur_ at a specific -time. Different actions can be taken upon the occurance of an event, +time. Different actions can be taken upon the occurrence of an event, like record the event's payload to a buffer. An **event record** is the representation of an event in a sub-buffer. A @@ -1823,7 +1757,7 @@ The LTTng project incorporates: * **LTTng-tools**: Libraries and command-line interface to control tracing sessions. ** <> (man:lttng-sessiond(8)). -** <> (man:lttng-consumerd(8)). +** <> (cmd:lttng-consumerd). ** <> (man:lttng-relayd(8)). ** <> (`liblttng-ctl`). ** <> (man:lttng(1)). @@ -2119,7 +2053,7 @@ running. You can also start the session daemon manually. .The consumer daemon. image::plumbing-consumerd.png[] -The _consumer daemon_, man:lttng-consumerd(8), is a daemon which shares +The _consumer daemon_, cmd:lttng-consumerd, is a daemon which shares ring buffers with user applications or with the LTTng kernel modules to collect trace data and send it to some location (on disk or to a <> over the network). The consumer daemon @@ -5406,12 +5340,12 @@ MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "." ---- -- -. Edit path:{probes/Makefile} and add your new kernel module object +. Edit path:{probes/KBuild} and add your new kernel module object next to the existing ones: + -- [source,make] -.path:{probes/Makefile} +.path:{probes/KBuild} ---- # ... @@ -6464,8 +6398,8 @@ leads to this whitelist: .PIDs 3, 7, 10, and 13 are removed from the whitelist. image::track-1-4-15-16.png[] -LTTng can track all possible PIDs again using the opt:track(1):--all -option: +LTTng can track all possible PIDs again using the +opt:lttng-track(1):--all option: [role="term"] ---- @@ -7275,7 +7209,7 @@ event:: or a Linux kernel KProbe. + An event is said to _occur_ at a specific time. Different actions can -be taken upon the occurance of an event, like record the event's payload +be taken upon the occurrence of an event, like record the event's payload to a sub-buffer. <>::