[[Image:images/LTTng2AssignedEvents.png]]
-=== Configuring Filter Expression On UST Event Fields ===
+=== Configuring Filter Expression When Enabling Events ===
-Since LTTng Tools v2.1.0 it is possible to configure a filter expression on UST event fields. To configure a filter expression on UST event fields, open the enable event dialog as described in chapters [[#Enabling UST Events On Session Level | Enabling UST Events On Session Level]], [[#Enabling Events On Domain Level | Enabling Events On Domain Level]] or [[#Enabling Events On Channel Level | Enabling Events On Channel Level]], select UST if needed, select the relevant '''Tracepoint''' event(s) and enter the filter expression in the '''Filter Expression''' text field.
+It is possible to provide a filter expression when enabling events for UST or Kernel. This feature has been available for UST since LTTng v2.1.0 and for Kernel since v2.7.0. To configure a filter expression, open the enable event dialog as described in previous chapters [[#Enabling UST Events On Session Level | Enabling UST Events On Session Level]], [[#Enabling Kernel Events On Session Level | Enabling Kernel Events On Session Level]], [[#Enabling Events On Domain Level | Enabling Events On Domain Level]] or [[#Enabling Events On Channel Level | Enabling Events On Channel Level]]. Then configure the relevant events and enter the filter expression in the '''Filter Expression''' text field.
-[[Image:images/LTTng2EnableEventWithFilter.png]]
+[[Image:images/LTTng2EnableEventWithFilter.png]] [[Image:images/LTTng2EnableEventWithKernelFilter.png]]
-Alternatively, open the dialog box for assigning events to a session and channel described in [[#Enabling Tracepoint Events From Provider | Enabling Tracepoint Events From Provider]] (for UST providers) and enter the filter expression in the '''Filter Expression''' text field.
+Alternatively, open the dialog box for assigning events to a session and channel described in [[#Enabling Tracepoint Events From Provider | Enabling Tracepoint Events From Provider]] and enter the filter expression in the '''Filter Expression''' text field.
[[Image:images/LTTng2AssignEventDialogWithFilter.png]]
Upon successful operation, the tree in the Control View will be refreshed with the remote host configuration.
-=== Quantifing LTTng overhead (Calibrate) ===
-
-The LTTng calibrate command can be used to find out the combined average overhead of the LTTng tracer and the instrumentation mechanisms used. For now, the only calibration implemented is that of the kernel function
-instrumentation (kretprobes). To run the calibrate command, select the a domain (e.g. '''Kernel'''), click the right mouse button on the domain tree node. A context-sensitive menu will show. Select the '''Calibrate''' menu item.
-
-[[Image:images/LTTng2CalibrateAction.png]]
-
-Upon successful operation, the calibrate command is executed and relevant information is stored in the trace. Note: that the trace has to be active so that to command as any effect.
-
=== Importing Session Traces to a Tracing Project ===
To import traces from a tracing session, select the relevant session and click on the '''Import''' Button. Alternatively, click the right mouse button on the session tree node and select the menu item '''Import...''' from the context-sensitive menu.
If one selects '''Rename All''', '''Overwrite All''' or '''Skip All''' the choice will be applied for all traces with a name conflict.
-
=== Importing Network Traces to a Tracing Project ===
Since LTTng Tools v2.1.0 it is possible to store traces over the network. To import network traces, execute the '''Import''' action as described in chapter [[#Importing Session Traces to a Tracing Project | Importing Session Traces to a Tracing Project]]. For network traces the '''Import Trace Wizard''' will be displayed. Follow the instructions in chapter [[#Importing | Importing]] to import the network traces of the current session.
+=== Saving Tracing Sessions ===
+Since LTTng Tools v2.5.0 it is possible to save tracing sessions. The LTTng Tools command-line tool will save the sessions to XML files located by default in a subdirectory of the user's home directory. The Trace Compass '''Control''' view integration for this feature will also store this session profile file into the user's Trace Compass workspace. This will allow user's to re-use session profiles across remote nodes. To save one or more sessions, select the tree nodes of the relevant sessions and press the right mouse button. Then select the '''Save...''' entry of the context-sensitive menu.
+
+[[Image:images/LTTng2SaveAction.png]]
+
+A new display will open for saving the sessions.
+
+[[Image:images/LTTng2SaveDialog.png]]
+
+By default the '''force''' button is selected that will overwrite any conflicting session profile files on the remote node. Click on '''Ok''' to save the session(s) otherwise click on '''Cancel'''. Upon successful operation, the session profile files will be saved on the remote node and then will be downloaded to the user's Trace Compass workspace. In the case that a session XML file already exists in the workspace the user will be prompted to skip or overwrite the existing profile file.
+
+=== Loading Tracing Sessions ===
+Since LTTng Tools v2.5.0 it is possible to load tracing sessions. The Trace Compass '''Control''' view integrations for this feature will allow to load session profiles that are located in the user's Trace Compass workspace, or alternatively, that are located on the remote node. In the first case the session profiles will be uploaded to the remote node before the load command is executed.
+
+To load one or more sessions, select the tree node '''Sessions''' and press the right mouse button. Then select the '''Load...''' entry of the context-sensitive menu.
+
+[[Image:images/LTTng2LoadAction.png]]
+
+A new display will open for loading session profiles.
+
+[[Image:images/LTTng2LoadDialog.png]]
+
+By default the '''Local''' button and '''force''' buttons are selected and session profile files of the user's workspace will be listed. Select one or more profiles, update the '''force''' button if needed and then click '''Ok'''. This will upload the session profile files to the remote node. If a session profile file with the same name already exist on the remote node, it will be overwritten. If the '''force''' button is selected any existing session with a conflicting name will be destroyed and a new one will be created.
+
+Alternatively, one can select the '''Remote''' button to list all available session profile files on the remote node. To load one of the remote session profiles, select one or more profiles, update the '''force''' button if needed and then click '''Ok'''.
+
+[[Image:images/LTTng2LoadRemoteDialog.png]]
+
+Upon successful operation, the tracing sessions of the selected session profiles are created and added under the tree node '''Sessions''' the '''Control''' view.
+
+=== Managing Tracing Session Profiles ===
+The '''LTTng Remote Profiles''' preference page is used to manage the list of LTTng session profiles that are stored in the user's Trace Compass workspace. To open the preference page, select the '''Manage...''' button of the '''Load Sessions''' dialog described in chapter [[#Loading Tracing Sessions |Loading Tracing Sessions]]. Alternatively, select '''Window -> Preferences''' from the top level menu and go to '''Tracing -> LTTng Remote Profiles'''.
+
+[[Image:images/LTTng2ManageSessionConfig.png]]
+
+The following actions can be performed from this dialog:
+
+* Delete
+
+Select one or more LTTng session profiles from the list and click the '''Delete''' button to remove the profile from the Trace Compass workspace. The user will be prompted to confirm the deletion.
+
+* Import...
+
+Click the '''Import...''' button and select a file from the opened file dialog to import a session profile file. If the file name conflicts with an existing profile file, the user will be prompted to skip or overwrite the existing profile file.
+* Export...
+
+Select one or more session profile files from the list, click the '''Export...''' button and enter or select a directory in the opened directory dialog to export the profile files. If the file name conflicts with an existing profile file in the destination directory, the user will be prompted to skip or overwrite the existing profile file.
+
== Properties View ==
The Control View provides property information of selected tree component. Depending on the selected tree component different properties are displayed in the property view. For example, when selecting the node level the property view will be filled as followed:
[[Image:images/LTTng2PreferencesTimeout.png]]
+
= LTTng Kernel Analysis =
Historically, LTTng was developped to trace the Linux kernel and, over time, a number of kernel-oriented analysis views were developped and organized in a perspective.
[[Image:images/XML_xy_chart.png| XML XY chart]]
+= Latency Analyses =
+
+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
+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 vs Time
+A time aligned '''scatter chart''' of the latencies with respect to the current window range. This view is useful to see the overall form of the latencies as they arrive.
+
+[[Image:images/LatenciesScatter.png| Latency Scatter Chart example - System Call Latency vs Time]]
+
+
+* 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.
+
+[[Image:images/LatenciesStatistics.png| Latency Statistics example - System Call Latency Statistics]]
+
+
+* System Call Density
+A '''density''' view, analyzing the current time range. This is useful to find global outliers.
+
+[[Image:images/LatenciesDensity.png| Latency Densities example - System Call Density]]
+
+
= Limitations =
* When parsing text traces, the timestamps are assumed to be in the local time zone. This means that when combining it to CTF binary traces, there could be offsets by a few hours depending on where the traces were taken and where they were read.
projects / deliverable / tracecompass.git / blobdiff