== Statistics View ==
-The Statistics View displays the various event counters that are collected when analyzing a trace. The data is organized per trace. After opening a trace, the element '''Statistics''' is added under the '''Tmf Statistics Analysis''' tree element in the Project Explorer. To open the view, double-click the '''Statistics''' tree element. Alternatively, select '''Statistics''' under '''Tracing''' within the '''Show View''' window ('''Window''' -> '''Show View''' -> '''Other...'''). This view shows 3 columns: ''Level'' ''Events total'' and ''Events in selected time range''. After parsing a trace the view will display the number of events per event type in the second column and in the third, the currently selected time range's event type distribution is shown. The cells where the number of events are printed also contain a colored bar with a number that indicates the percentage of the event count in relation to the total number of events. The statistics is collected for the whole trace. This view is part of the '''Tracing and Monitoring Framework (TMF)''' and is generic. It will work for any trace type extensions. For the LTTng 2.0 integration the Statistics view will display statistics as shown below.:
+The Statistics View displays the various event counters that are collected when analyzing a trace. After opening a trace, the element '''Statistics''' is added under the '''Tmf Statistics Analysis''' tree element in the Project Explorer. To open the view, double-click the '''Statistics''' tree element. Alternatively, select '''Statistics''' under '''Tracing''' within the '''Show View''' window ('''Window''' -> '''Show View''' -> '''Other...'''). The statistics is collected for the whole trace. This view is part of the '''Tracing and Monitoring Framework (TMF)''' and is generic. It will work for any trace type extensions.
-[[Image:images/LTTng2StatisticsView.png]]
+The view is separated in two sides. The left side of the view presents the Statistics in a table. The table shows 3 columns: ''Level'' ''Events total'' and ''Events in selected time range''. The data is organized per trace. After parsing a trace the view will display the number of events per event type in the second column and in the third, the currently selected time range's event type distribution is shown. The cells where the number of events are printed also contain a colored bar with a number that indicates the percentage of the event count in relation to the total number of events.
+
+[[Image:images/LTTng2StatisticsTableView.png]]
+
+The right side illustrates the proportion of types of events into two pie charts. The legend of each pie chart gives the representation of each color in the chart.
+* The ''Global'' pie chart displays the general proportion of the events in the trace.
+* When there is a range selection, the ''Events in selection'' pie chart appears next to the ''Global'' pie chart and displays the proportion the event in the selected range of the trace.
+
+[[Image:images/LTTng2StatisticsPieChartView.png]]
By default, the statistics use a state system, therefore will load very quickly once the state system is written to the disk as a supplementary file.
[[Image:images/waitAnalysis/KernelWaitAnalysisDjango.png]]
+== Input/Output Analysis ==
+
+TraceCompass can analyse disk input/output through the read/write system calls to get the read/write per processes, but also with the disk request events, to get the actual reads and writes to disk.
+
+=== Get the trace ===
+
+The following tracepoints should be enabled to get the disk read/write data. Also, enabling syscalls will allow to match the reads and writes per processes.
+
+ # sudo lttng list -k
+ Kernel events:
+ -------------
+ ...
+ block_rq_complete (loglevel: TRACE_EMERG (0)) (type: tracepoint)
+ block_rq_insert (loglevel: TRACE_EMERG (0)) (type: tracepoint)
+ block_rq_issue (loglevel: TRACE_EMERG (0)) (type: tracepoint) # on the guest
+ block_bio_frontmerge (loglevel: TRACE_EMERG (0)) (type: tracepoint) # on the guest
+ ...
+
+For full disk request tracking, some extra tracepoints are necessary. They are not required for the I/O analysis, but make the analysis more complete. Here is the procedure to get those tracepoints that are not yet part of the mainline kernel.
+
+ # git clone https://github.com/giraldeau/lttng-modules.git
+ # cd lttng-modules
+
+Checkout the addons branch, compile and install lttng-modules as per the lttng-modules documentation.
+
+ # git checkout addons
+ # make
+ # sudo make modules_install
+ # sudo depmod -a
+
+The lttng addons modules must be inserted manually for the extra tracepoints to be available:
+
+ # sudo modprobe lttng-addons
+ # sudo modprobe lttng-elv
+
+And enable the following tracepoint
+
+ addons_elv_merge_requests
+
+=== Input/Output Views ===
+
+The following views are available for input/output analyses:
+
+* Disk I/O Activity
+A time aligned XY chart of the read and write speed for the different disks on the system. This view is useful to see where there was more activity on the disks and whether it was mostly reads or writes.
+
+ [[Image:images/io/diskIoActivity.png| Disk I/O Activity Example]]
== LTTng Kernel Events Editor ==
Trace Compass offers a feature called Latency analysis. This allows an analysis to return intervals and these intervals will be displayed in four different views. An example analysis is provided with kernel system call latencies being provided. The available views are:
-* System Call Latencies
+* System Call Latencies
A '''table''' of the raw latencies. This view is useful to inspect individual latencies.
[[Image:images/LatenciesTable.png| Latency Table example - System Call Latencies]]
* System Call Latency Statistics
-A view of the total '''statistics''' of the latencies. These show the ''minimum'', ''maximum'', ''average'' and ''standard deviation'' of the latencies when applicable. This tool is useful for finding the outliers on a per-category basis.
+A view of the total '''statistics''' of the latencies. These show the ''minimum'', ''maximum'', ''average'', ''standard deviation'', and ''count'' of the latencies when applicable. This tool is useful for finding the outliers on a per-category basis.
+
+Right-clicking on an entry of the table and select '''Go to minimum''' allows to select the range of the minimum latency for the selected entry and synchronize the other views to this time range.
+
+Right-clicking on an entry of the table and select '''Go to maximum''' allows to select the range of the maximum latency for the selected entry and synchronize the other views to this time range.
[[Image:images/LatenciesStatistics.png| Latency Statistics example - System Call Latency Statistics]]
projects / deliverable / tracecompass.git / blobdiff