node = (HOST);
edge = (LINK);
- HOST = {
- size = power;
- scale = global;
-
- sep_host = {
- type = separation;
- size = power;
- values = (pcompute, pfinalize);
- };
- };
- LINK = {
- src = source;
- dst = destination;
- size = bandwidth;\section tracing_tracing Tracing Simulations for Visualization
-
-The trace visualization is widely used to observe and understand the behavior
-of parallel applications and distributed algorithms. Usually, this is done in a
-two-step fashion: the user instruments the application and the traces are
-analyzed after the end of the execution. The visualization itself can highlights
-unexpected behaviors, bottlenecks and sometimes can be used to correct
-distributed algorithms. The SimGrid team has instrumented the library
-in order to let users trace their simulations and analyze them. This part of the
-user manual explains how the tracing-related features can be enabled and used
-during the development of simulators using the SimGrid library.
-
-\subsection tracing_tracing_howitworks How it works
-
-For now, the SimGrid library is instrumented so users can trace the <b>platform
-utilization</b> using the MSG, SimDAG and SMPI interface. This means that the tracing will
-register how much power is used for each host and how much bandwidth is used for
-each link of the platform. The idea with this type of tracing is to observe the
-overall view of resources utilization in the first place, especially the
-identification of bottlenecks, load-balancing among hosts, and so on.
-
-The idea of the tracing facilities is to give SimGrid users to possibility to
-classify MSG and SimDAG tasks by category, tracing the platform utilization
-(hosts and links) for each of the categories. For that,
-the tracing interface enables the declaration of categories and a function to
-mark a task with a previously declared category. <em>The tasks that are not
-classified according to a category are not traced</em>. Even if the user
-does not specify any category, the simulations can still be traced in terms
-of resource utilization by using a special parameter that is detailed below.
-
-\subsection tracing_tracing_enabling Enabling using CMake
-
-With the sources of SimGrid, it is possible to enable the tracing
-using the parameter <b>-Denable_tracing=ON</b> when the cmake is executed.
-The section \ref tracing_tracing_functions describes all the functions available
-when this Cmake options is activated. These functions will have no effect
-if SimGrid is configured without this option (they are wiped-out by the
-C-preprocessor).
-
-\verbatim
-$ cmake -Denable_tracing=ON .
-$ make
-\endverbatim
-
-\subsection tracing_tracing_functions Tracing Functions
-
-\li <b>\c TRACE_category (const char *category)</b>: This function should be used
-to define a user category. The category can be used to differentiate the tasks
-that are created during the simulation (for example, tasks from server1,
-server2, or request tasks, computation tasks, communication tasks).
-All resource utilization (host power and link bandwidth) will be
-classified according to the task category. Tasks that do not belong to a
-category are not traced. The color for the category that is being declared
-is random (use next function to specify a color).
-
-\li <b>\c TRACE_category_with_color (const char *category, const char *color)</b>: Same
-as TRACE_category, but let user specify a color encoded as a RGB-like string with
-three floats from 0 to 1. So, to specify a red color, the user can pass "1 0 0" as
-color parameter. A light-gray color can be specified using "0.7 0.7 0.7" as color.
-
-\li <b>\c TRACE_msg_set_task_category (m_task_t task, const char *category)</b>:
-This function should be called after the creation of a MSG task, to define the
-category of that task. The first parameter \c task must contain a task that was
-created with the function \c MSG_task_create. The second parameter
-\c category must contain a category that was previously defined by the function
-\c TRACE_category.
-
-\li <b>\c TRACE_sd_set_task_category (SD_task_t task, const char *category)</b>:
-This function should be called after the creation of a SimDAG task, to define the
-category of that task. The first parameter \c task must contain a task that was
-created with the function \c MSG_task_create. The second parameter
-\c category must contain a category that was previously defined by the function
-\c TRACE_category.
-
-\li <b>\c TRACE_[host|link]_variable_declare (const char *variable)</b>:
-Declare a user variable that will be associated to host/link. A variable can
-be used to trace user variables such as the number of tasks in a server,
-the number of clients in an application (for hosts), and so on.
-
-\li <b>\c TRACE_[host|link]_variable_[set|add|sub] (const char *[host|link], const char *variable, double value)</b>:
-Set the value of a given user variable for a given host/link. The value
-of this variable is always associated to the host/link. The host/link
-parameters should be its name as the one listed in the platform file.
-
-\li <b>\c TRACE_[host|link]_variable_[set|add|sub]_with_time (double time, const char *[host|link], const char *variable, double value)</b>:
-Same as TRACE_[host|link]_variable_[set|add|sub], but let user specify
-the time used to trace it. Users can specify a time that is not the
-simulated clock time as defined by the core simulator. This allows
-a fine-grain control of time definition, but should be used with
-caution since the trace can be inconsistent if resource utilization
-traces are also traced.
-
-\li <b>\c TRACE_link_srcdst_variable_[set|add|sub] (const char *src, const char *dst, const char *variable, double value)</b>:
-Same as TRACE_link_variable_[set|add|sub], but now users specify a source and
-destination hosts (as the names from the platform file). The tracing library
-will get the corresponding route that connects those two hosts (src and dst) and
-[set|add|sub] the value's variable for all the links of the route.
-
-\li <b>\c TRACE_link_srcdst_variable_[set|add|sub]_with_time (double time, const char *src, const char *dst, const char *variable, double value)</b>:
-Same as TRACE_link_srcdst_variable_[set|add|sub], but user specify a time different from the simulated time.
-
-\subsection tracing_tracing_options Tracing configuration Options
-
-These are the options accepted by the tracing system of SimGrid:
-
-\li <b>\c
-tracing
-</b>:
- Safe switch. It activates (or deactivates) the tracing system.
- No other tracing options take effect if this one is not activated.
-
-\li <b>\c
-tracing/platform
-</b>:
- Register the simulation platform in the trace file.
-
-\li <b>\c
-tracing/onelink_only
-</b>:
- By default, the tracing system uses all routes in the platform file
- to re-create a "graph" of the platform and register it in the trace file.
- This option let the user tell the tracing system to use only the routes
- that are composed with just one link.
-
-\li <b>\c
-tracing/categorized
-</b>:
- It activates the categorized resource utilization tracing. It should
- be enabled if tracing categories are used by this simulator.
-
-\li <b>\c
-tracing/uncategorized
-</b>:
- It activates the uncategorized resource utilization tracing. Use it if
- this simulator do not use tracing categories and resource use have to be
- traced.
-
-\li <b>\c
-tracing/filename
-</b>:
- A file with this name will be created to register the simulation. The file
- is in the Paje format and can be analyzed using Triva or Paje visualization
- tools. More information can be found in these webpages:
- <a href="http://triva.gforge.inria.fr/">http://triva.gforge.inria.fr/</a>
- <a href="http://paje.sourceforge.net/">http://paje.sourceforge.net/</a>
-
-\li <b>\c
-tracing/smpi
-</b>:
- This option only has effect if this simulator is SMPI-based. Traces the MPI
- interface and generates a trace that can be analyzed using Gantt-like
- visualizations. Every MPI function (implemented by SMPI) is transformed in a
- state, and point-to-point communications can be analyzed with arrows.
-
-\li <b>\c
-tracing/smpi/group
-</b>:
- This option only has effect if this simulator is SMPI-based. The processes
- are grouped by the hosts where they were executed.
-
-\li <b>\c
-tracing/msg/task
-</b>:
- This option only has effect if this simulator is MSG-based. It traces the
- behavior of all categorized MSG tasks, grouping them by hosts.
-
-\li <b>\c
-tracing/msg/process
-</b>:
- This option only has effect if this simulator is MSG-based. It traces the
- behavior of all categorized MSG processes, grouping them by hosts. This option
- can be used to track process location if this simulator has process migration.
-
-
-\li <b>\c
-triva/categorized:graph_categorized.plist
-</b>:
- This option generates a graph configuration file for Triva considering
- categorized resource utilization.
-
-\li <b>\c
-triva/uncategorized:graph_uncategorized.plist
-</b>:
- This option generates a graph configuration file for Triva considering
- uncategorized resource utilization.
-
-\subsection tracing_tracing_example Example of Instrumentation
-
-A simplified example using the tracing mandatory functions.
-
-\verbatim
-int main (int argc, char **argv)
-{
- MSG_global_init (&argc, &argv);
-
- //(... after deployment ...)
-
- //note that category declaration must be called after MSG_create_environment
- TRACE_category_with_color ("request", "1 0 0");
- TRACE_category_with_color ("computation", "0.3 1 0.4");
- TRACE_category ("finalize");
-
- m_task_t req1 = MSG_task_create("1st_request_task", 10, 10, NULL);
- m_task_t req2 = MSG_task_create("2nd_request_task", 10, 10, NULL);
- m_task_t req3 = MSG_task_create("3rd_request_task", 10, 10, NULL);
- m_task_t req4 = MSG_task_create("4th_request_task", 10, 10, NULL);
- TRACE_msg_set_task_category (req1, "request");
- TRACE_msg_set_task_category (req2, "request");
- TRACE_msg_set_task_category (req3, "request");
- TRACE_msg_set_task_category (req4, "request");
-
- m_task_t comp = MSG_task_create ("comp_task", 100, 100, NULL);
- TRACE_msg_set_task_category (comp, "computation");
-
- m_task_t finalize = MSG_task_create ("finalize", 0, 0, NULL);
- TRACE_msg_set_task_category (finalize, "finalize");
-
- //(...)
-
- MSG_clean();
- return 0;
-}
-\endverbatim
-
-\subsection tracing_tracing_analyzing Analyzing the SimGrid Traces
-
-The SimGrid library, during an instrumented simulation, creates a trace file in
-the Paje file format that contains the platform utilization for the simulation
-that was executed. The visualization analysis of this file is performed with the
-visualization tool <a href="http://triva.gforge.inria.fr">Triva</a>, with
-special configurations tunned to SimGrid needs. This part of the documentation
-explains how to configure and use Triva to analyse a SimGrid trace file.
-
-- <b>Installing Triva</b>: the tool is available in the INRIAGforge,
-at <a href="http://triva.gforge.inria.fr">http://triva.gforge.inria.fr</a>.
-Use the following command to get the sources, and then check the file
-<i>INSTALL</i>. This file contains instructions to install
-the tool's dependencies in a Ubuntu/Debian Linux. The tool can also
-be compiled in MacOSes natively, check <i>INSTALL.mac</i> file.
-\verbatim
-$ svn checkout svn://scm.gforge.inria.fr/svn/triva
-$ cd triva
-$ cat INSTALL
-\endverbatim
-
-- <b>Executing Triva</b>: a binary called <i>Triva</i> is available after the
- installation (you can execute it passing <em>--help</em> to check its
-options). If the triva binary is not available after following the
-installation instructions, you may want to execute the following command to
-initialize the GNUstep environment variables. We strongly recommend that you
-use the latest GNUstep packages, and not the packages available through apt-get
-in Ubuntu/Debian packaging systems. If you install GNUstep using the latest
-available packages, you can execute this command:
-\verbatim
-$ source /usr/GNUstep/System/Library/Makefiles/GNUstep.sh
-\endverbatim
-You should be able to see this output after the installation of triva:
-\verbatim
-$ ./Triva.app/Triva --help
-Usage: Triva [OPTIONS...] TRACE0 [TRACE1]
-Trace Analysis through Visualization
-
-TimeInterval
- --ti_frequency {double} Animation: frequency of updates
- --ti_hide Hide the TimeInterval window
- --ti_forward {double} Animation: value to move time-slice
- --ti_apply Apply the configuration
- --ti_update Update on slider change
- --ti_animate Start animation
- --ti_start {double} Start of time slice
- --ti_size {double} Size of time slice
-Triva
- --comparison Compare Trace Files (Experimental)
- --graph Configurable Graph
- --list Print Trace Type Hierarchy
- --hierarchy Export Trace Type Hierarchy (dot)
- --stat Trace Statistics and Memory Utilization
- --instances List All Trace Entities
- --linkview Link View (Experimental)
- --treemap Squarified Treemap
- --merge Merge Trace Files (Experimental)
- --check Check Trace File Integrity
-GraphConfiguration
- --gc_conf {file} Graph Configuration in Property List Format
- --gc_apply Apply the configuration
- --gc_hide Hide the GraphConfiguration window
-\endverbatim
-Triva expects that the user choose one of the available options
-(currently <em>--graph</em> or <em>--treemap</em> for a visualization analysis)
-and the trace file from the simulation.
-
-- <b>Understanding Triva - time-slice</b>: the analysis of a trace file using
- the tool always takes into account the concept of the <em>time-slice</em>.
-This concept means that what is being visualized in the screen is always
-calculated considering a specific time frame, with its beggining and end
-timestamp. The time-slice is configured by the user and can be changed
-dynamically through the window called <em>Time Interval</em> that is opened
-whenever a trace file is being analyzed. The next figure depicts the time-slice
-configuration window.
-In the top of the window, in the space named <i>Trace Time</i>,
-the two fields show the beggining of the trace (which usually starts in 0) and
-the end (that depends on the time simulated by SimGrid). The middle of the
-window, in the square named <i>Time Slice Configuration</i>, contains the
-aspects related to the time-slice, including its <i>start</i> and its
-<i>size</i>. The gray rectangle in the bottom of this part indicates the
-<i>current time-slice</i> that is considered for the drawings. If the checkbox
-<i>Update Drawings on Sliders Change</i> is not selected, the button
-<i>Apply</i> must be clicked in order to inform triva that the
-new time-slice must be considered. The bottom part of the window, in the space
-indicated by the square <i>Time Slice Animation</i> can be used to advance
-the time-frame automatically. The user configures the amount of time that the
-time-frame will forward and how frequent this update will happen. Once this is
-configured, the user clicks the <i>Play</i> button in order to see the dynamic
-changes on the drawings.
-<center>
-\htmlonly
-<a href="triva-time_interval.png" border=0><img src="triva-time_interval.png" width="50%" border=0></a>
-\endhtmlonly
-</center>
-<b>Remarks:</b> when the trace has too many hosts or links, the computation to
-take into account a new time-slice can be expensive. When this happens, the
-<i>Frequency</i> parameter, but also updates caused by change on configurations
-when the checkbox <i>Update Drawings on Sliders
-Change</i> is selected will not be followed.
-
-- <b>Understanding Triva - graph</b>: this part of the documention explains how
- to analyze the traces using the graph view of Triva, when the user executes
-the tool passing <em>--graph</em> as parameter. Triva opens three windows when
-this parameter is used: the <i>Time Interval</i> window (previously described),
-the <i>Graph Representation</i> window, and the <em>Graph Configuration</em>
-window. The Graph Representation is the window where drawings take place.
-Initially, it is completely white waiting for a proper graph configuration input
-by the user. We start the description of this type of analysis by describing the
-<i>Graph Configuration</i> window (depicted below). By using a particular
-configuration, triva
-can be used to customize the graph drawing according to
-the SimGrid trace that was created with user-specific categories. Before delving
-into the details of this customization, let us first explain the major parts of
-the graph configuration window. The buttons located in the top-right corner can
-be used to delete, copy and create a new configuration. The checkbox in the
-top-middle part of the window indicates if the configuration typed in the
-textfield is syntactically correct (we are using the non-XML
-<a href="http://en.wikipedia.org/wiki/Property_list">Property List Format</a> to
-describe the configuration). The pop-up button located on the top-left corner
-indicates the selected configuration (the user can have multiple graph
-configurations). The bottom-left text field contains the name of the current
-configuration (updates on this field must be followed by typing enter on the
-keyboard to take into account the name change). The bottom-right <em>Apply</em>
-button activates the current configuration, resulting on an update on the graph
-drawings.
-<center>
-\htmlonly
-<a href="triva-graph_configuration.png" border=0><img src="triva-graph_configuration.png" width="50%" border=0></a>
-\endhtmlonly
-</center>
-<b>Basic SimGrid Configuration</b>: The figure shows in the big textfield the
-basic configuration that should be used during the analysis of a SimGrid trace
-file. The basic logic of the configuration is as follows:
-\verbatim
-{
- node = (HOST);
- edge = (LINK);
-\endverbatim
-The nodes of the graph will be created based on the <i>node</i> parameter, which
-in this case is the different <em>"HOST"</em>s of the platform
-used to simulate. The <i>edge</i> parameter indicates that the edges of the
-graph will be created based on the <em>"LINK"</em>s of the platform. After the
-definition of these two parameters, the configuration must detail how
-<em>HOST</em>s and <em>LINK</em>s should be drawn. For that, the configuration
-must have an entry for each of the types used. For <em>HOST</em>, as basic
-configuration, we have:
-\verbatim
- HOST = {
- size = power;
- scale = global;
- };
-\endverbatim
-The parameter <em>size</em> indicates which variable from the trace file will be
-used to define the size of the node HOST in the visualization. If the simulation
-was executed with availability traces, the size of the nodes will be changed
-according to these traces. The parameter <em>scale</em> indicates if the value
-of the variable is <em>global</em> or <em>local</em>. If it is global, the value
-will be relative to the power of all other hosts, if it is local, the value will
-be relative locally.
-For <em>LINK</em> we have:
-\verbatim
- LINK = {
- src = source;
- dst = destination;
-
- size = bandwidth;
- scale = global;
- };
-\endverbatim
-For the types specified in the <em>edge</em> parameter (such as <em>LINK</em>),
-the configuration must contain two additional parameters: <em>src</em> and
-<em>dst</em> that are used to properly identify which nodes this edge is
-connecting. The values <em>source</em> and <em>destination</em> are always present
-in the SimGrid trace file and should not be changed in the configuration. The
-parameter <em>size</em> for the LINK, in this case, is configured as the
-variable <em>bandwidth</em>, with a <em>global</em> scale. The scale meaning
-here is exactly the same used for nodes. The last parameter is the GraphViz
-algorithm used to calculate the position of the nodes in the graph
-representation.
-\verbatim
- graphviz-algorithm = neato;
-}
-\endverbatim
-<b>Customizing the Graph Representation</b>: triva is capable to handle
-a customized graph representation based on the variables present in the trace
-file. In the case of SimGrid, every time a category is created for tasks, two
-variables in the trace file are defined: one to indicate node utilization (how
-much power was used by that task category), and another to indicate link
-utilization (how much bandwidth was used by that category). For instance, if the
-user declares a category named <i>request</i>, there will be variables named
-<b>p</b><i>request</i> and a <b>b</b><i>request</i> (<b>p</b> for power and
-<b>b</b> for bandwidth). It is important to notice that the variable
-<i>prequest</i> in this case is only available for HOST, and
-<i>brequest</i> is only available for LINK. <b>Example</b>: suppose there are
-two categories for tasks: request and compute. To create a customized graph
-representation with a proportional separation of host and link utilization, use
-as configuration for HOST and LINK this:
-\verbatim
- HOST = {
- size = power;
- scale = global;
-
- sep_host = {
- type = separation;
- size = power;
- values = (prequest, pcomputation);
- };
- };
-
- LINK = {
- src = source;
- dst = destination;
- size = bandwidth;
- scale = global;
-
- sep_link = {
- type = separation;
- size = bandwidth;
- values = (brequest, bcomputation);
- };
- };
-\endverbatim
-Where <i>sep_host</i> contains a composition of type <i>separation</i> where
-its max size is the <i>power</i> of the host and the variables <i>prequest</i>
-and <i>pcomputation</i> are drawn proportionally to the size of the HOST. And
-<i>sep_link</i> is also a separation where max is defined as the
-<i>bandwidth</i> of the link, and the variables <i>brequest</i> and
-<i>bcomputation</i> are drawn proportionally within a LINK.
-<i>This configuration enables the analysis of resource utilization by MSG tasks,
-and the identification of load-balancing issues, network bottlenecks, for
-instance.</i> \n
-<b>Other compositions</b>: besides <i>separation</i>, it is possible to use
-other types of compositions, such as gradients, and colors, like this:
-\verbatim
- gra_host = {
- type = gradient;
- scale = global;
- values = (numberOfTasks);
- };
- color_host = {
- type = color;
- values = (is_server);
- };
-\endverbatim
-Where <i>gra_host</i> creates a gradient within a node of the graph, using a
-global scale and using as value a variable called <i>numberOfTasks</i>, that
-could be declared by the user using the optional tracing functions of SimGrid.
-If scale is global, the max and min value for the gradient will be equal to the
-max and min numberOfTasks among all hosts, and if scale is local, the max and
-min value based on the value of numberOfTasks locally in each host.
-And <i>color_host</i> composition draws a square based on a positive value of
-the variable <i>is_server</i>, that could also be defined by the user using the
-SimGrid tracing functions. \n
-<b>The Graph Visualization</b>: The next figure shows a graph visualization of a
-given time-slice of the masterslave_forwarder example (present in the SimGrid
-sources). The red color indicates tasks from the <i>compute</i> category. This
-visualization was generated with the following configuration:
-\verbatim
-{
- node = (HOST);
- edge = (LINK);
-
HOST = {
size = power;
scale = global;
\endhtmlonly
</center>
-- <b>Understading Triva - colors</b>: An important issue when using Triva is how
- to define colors. To do that, we have to know which variables are defined in
-the trace file generated by the SimGrid library. The parameter <em>--list</em>
-lists the variables for a given trace file:
-\verbatim
-$ Triva -l masterslave_forwarder.trace
-iFile
-c platform
-c HOST
-v power
-v is_slave
-v is_master
-v task_creation
-v task_computation
-v pcompute
-v pfinalize
-c LINK
-v bandwidth
-v latency
-v bcompute
-v bfinalize
-c user_type
-\endverbatim
-We can see that HOST has seven variables (from power to pfinalize) and LINK has
-four (from bandwidth to bfinalize). To define a red color for the
-<i>pcompute</i> and <i>bcompute</i> (which are defined based on user category
-<i>compute</i>), execute:
-\verbatim
-$ defaults write Triva 'pcompute Color' '1 0 0'
-$ defaults write Triva 'bcompute Color' '1 0 0'
-\endverbatim
-Where the three numbers in each line are the RGB color with values from 0 to 1.
-\verbatim
- scale = global;
-
- sep_link = {
- type = separation;
- size = bandwidth;
- values = (bcompute, bfinalize);
- };
- };
- graphviz-algorithm = neato;
-}
-\endverbatim
-<center>
-\htmlonly
-<a href="triva-graph_visualization.png" border=0><img src="triva-graph_visualization.png" width="50%" border=0></a>
-\endhtmlonly
-</center>
-
- <b>Understading Triva - colors</b>: An important issue when using Triva is how
to define colors. To do that, we have to know which variables are defined in
the trace file generated by the SimGrid library. The parameter <em>--list</em>
