Added bag-of-task example (#157)

conf/cmake/Examples.cmake

@@ -3,6 +3,7 @@ set(EXAMPLES_CMAKEFILES_TXT
         examples/simple-example/CMakeLists.txt
         examples/basic-examples/bare-metal-chain/CMakeLists.txt
         examples/basic-examples/bare-metal-chain-scratch/CMakeLists.txt
+        examples/basic-examples/bare-metal-bag-of-tasks/CMakeLists.txt
         )
 
 foreach (cmakefile ${EXAMPLES_CMAKEFILES_TXT})

examples/README.md

@@ -1,36 +1,44 @@
 ## WRENCH Examples
 
-The ```examples``` directory in the WRENCH distribution contains several 
-example simulators that showcase the use of the WRENCH APIs.  Each 
+The ```examples``` directory in the WRENCH distribution contains several
+example simulators that showcase the use of the WRENCH APIs.  Each
 simulator (implemented using the WRENCH user API) simulates
- the execution of a workflow by a custom Workflow Management System (implemented
- using the WRENCH developer API). 
+ the execution of a workflow by a custom Workflow Management System
+ (implemented using the WRENCH developer API).
 
-Below are 
-high-level descriptions of the example in each sub-directory. Details on
-the specifics of each simulator are in extensive source code
- comments. 
+Below are high-level descriptions of the example in each sub-directory.
+Details on the specifics of each simulator are in extensive source code
+ comments.
 
 ### Basic simulators using a bare-metal service
 
-These simulators showcase the simplest use cases, simulating the execution of 
-simple applications on small hardware platforms that run instances of the **bare-metal
-compute service** and of the simple storage service. The bare-metal service
-is the simplest of the compute services implemented in WRENCH, which is why it is
-used in these examples.
-
-  - ```bare-metal-chain```: A simulation of the execution of a 
-    chain workflow by a Workflow Management System on a compute service, with all workflow data being read/written
-    from/to a single storage service. The compute  service runs on a 10-core host, and each task
-    is executed as a single job  that uses 10 cores
-
-  - ```bare-metal-chain-scratch```: Similar, but the compute service now has
-        scratch space to hold intermediate workflow files. Since  files created in the scratch
-        space during a job's execution are erased after that job's completion. As a result,
-        the workflow is executed as a single multi-task job.
-
-  - ```bare-metal-bag-of-tasks```: A simulation of the execution of a 
-     bag-of-task workflow by a Workflow Management System on a compute service, with all workflow data being read/written
-     from/to a single storage service. Up to two workflow tasks are executed concurrently on the compute service, in which case
-     one task is executed on 6 cores and the other on 4 cores. 
+These simulators showcase the simplest use cases, simulating the execution
+of simple applications on small hardware platforms that run instances of
+the **bare-metal compute service** and of the simple storage service. The
+bare-metal service is the simplest of the compute services implemented in
+WRENCH, which is why it is used in these examples.
+
+  - ```bare-metal-chain```: A simulation of the execution of a
+    chain workflow by a Workflow Management System on a compute service,
+    with all workflow data being read/written from/to a single storage
+    service. The compute  service runs on a 10-core host, and each task is
+    executed as a single job  that uses 10 cores
+
+  - ```bare-metal-chain-scratch```: Similar, but the compute service now
+    has scratch space to hold intermediate workflow files. Since  files
+    created in the scratch space during a job's execution are erased after
+    that job's completion. As a result, the workflow is executed as a single
+    multi-task job.
+
+  - ```bare-metal-bag-of-tasks```: A simulation of the execution of a
+     bag-of-task workflow by a Workflow Management System on a compute
+     service, with all workflow data being read/written from/to a single
+     storage service. Up to two workflow tasks are executed concurrently on
+     the compute service, in which case one task is executed on 6 cores and
+     the other on 4 cores.
+
+  - ```bare-metal-complex-job```: A simulation of the execution of a
+    one-task workflow on a compute service as a job that includes not long
+    the task computation but also data movements.
+
 

examples/basic-examples/bare-metal-bag-of-tasks/BareMetalBagOfTasks.cpp

@@ -0,0 +1,159 @@
+/**
+ * Copyright (c) 2017-2018. The WRENCH Team.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ */
+
+/**
+ ** This simulator simulates the execution of a bag-of-tasks workflow, that is, of a workflow
+ ** in which each task has its own input file and its own output file, and tasks can be
+ ** executed completely independently
+ **
+ **   InputFile #0 -> Task #0 -> OutputFile #1
+ **   ...
+ **   InputFile #n -> Task #n -> OutputFile #n
+ **
+ ** The compute platform comprises two hosts, WMSHost and ComputeHost. On WMSHost runs a simple storage
+ ** service and a WMS (defined in class OneTaskAtATimeWMS). On ComputeHost runs a bare metal
+ ** compute service, that has access to the 10 cores of that host. Once the simulation is done,
+ ** the completion time of each workflow task is printed.
+ **
+ ** Example invocation of the simulator for a 10-task workflow, with only WMS logging:
+ **    ./bare-metal-bag-of-tasks-simulator 10 ./two_hosts.xml --wrench-no-logs --log=one_task_at_a_time_wms.threshold=info
+ **
+ ** Example invocation of the simulator for a 5-task workflow with full logging:
+ **    ./bare-metal-bag-of-tasks-simulator 5 ./two_hosts.xml
+ **/
+
+
+#include <iostream>
+#include <wrench.h>
+
+#include "TwoTasksAtATimeWMS.h" // WMS implementation
+
+/**
+ * @brief The Simulator's main function
+ *
+ * @param argc: argument count
+ * @param argv: argument array
+ * @return 0 on success, non-zero otherwise
+ */
+int main(int argc, char **argv) {
+
+    /*
+     * Declare a WRENCH simulation object
+     */
+    wrench::Simulation simulation;
+
+    /* Initialize the simulation, which may entail extracting WRENCH-specific and
+     * Simgrid-specific command-line arguments that can modify general simulation behavior.
+     * Two special command-line arguments are --help-wrench and --help-simgrid, which print
+     * details about available command-line arguments. */
+    simulation.init(&argc, argv);
+
+    /* Parsing of the command-line arguments for this WRENCH simulation */
+    if (argc != 3) {
+        std::cerr << "Usage: " << argv[0] << " <number of tasks> <xml platform file> [optional logging arguments]" << std::endl;
+        exit(1);
+    }
+
+    /* Reading and parsing the platform description file, written in XML following the SimGrid-defined DTD,
+     * to instantiate the simulated platform */
+    std::cerr << "Instantiating simulated platform..." << std::endl;
+    simulation.instantiatePlatform(argv[2]);
+
+    /* Parse the first command-line argument (number of tasks) */
+    int num_tasks = 0;
+    try {
+        num_tasks = std::atoi(argv[1]);
+    } catch (std::invalid_argument &e) {
+        std::cerr << "Invalid number of tasks\n";
+        exit(1);
+    }
+
+    /* Declare a workflow */
+    wrench::Workflow workflow;
+
+    /* Initialize and seed a RNG */
+    std::uniform_int_distribution<double> dist(100000000.0,10000000000.0);
+    std::mt19937 rng(42);
+
+    /* Add workflow tasks and files */
+    for (int i=0; i < num_tasks; i++) {
+        /* Create a task: 10GFlop, 1 to 10 cores, 0.90 parallel efficiency, 10MB memory footprint */
+        auto task = workflow.addTask("task_" + std::to_string(i), dist(rng), 1, 10, 0.90, 10000000);
+        task->addInputFile(workflow.addFile("input_" + std::to_string(i), 10000000));
+        task->addOutputFile(workflow.addFile("output_" + std::to_string(i), 10000000));
+    }
+
+    /* Instantiate a storage service, and add it to the simulation.
+     * A wrench::StorageService is an abstraction of a service on
+     * which files can be written and read.  This particular storage service, which is an instance
+     * of wrench::SimpleStorageService, is started on WMSHost in the
+     * platform , which has an attached disk mounted at "/". The SimpleStorageService
+     * is a basic storage service implementation provided by WRENCH.
+     * Throughout the simulation execution, input/output files of workflow tasks will be located
+     * in this storage service, and accessed remotely by the compute service. Note that the
+     * storage service is configured to use a buffer size of 50M when transferring data over
+     * the network (i.e., to pipeline disk reads/writes and network revs/sends). */
+    std::cerr << "Instantiating a SimpleStorageService on WMSHost..." << std::endl;
+    auto storage_service = simulation.add(new wrench::SimpleStorageService(
+            "WMSHost", {"/"}, {{wrench::SimpleStorageServiceProperty::BUFFER_SIZE, "50000000"}}, {}));
+
+    /* Instantiate a bare-metal compute service, and add it to the simulation.
+     * A wrench::BareMetalComputeService is an abstraction of a compute service that corresponds to a
+     * to a software infrastructure that can execute tasks on hardware resources.
+     * This particular service is started on ComputeHost and has no scratch storage space (mount point argument = "").
+     * This means that tasks running on this service will access data only from remote storage services. */
+    std::cerr << "Instantiating a BareMetalComputeService on WMSHost..." << std::endl;
+    auto baremetal_service = simulation.add(new wrench::BareMetalComputeService(
+            "ComputeHost", {"ComputeHost"}, "", {}, {}));
+
+    /* Instantiate a WMS, to be stated on WMSHost, which is responsible
+     * for executing the workflow. See comments in TwoTasksAtATimeWMS.cpp
+     * for more details */
+
+    auto wms = simulation.add(
+            new wrench::TwoTasksAtATimeWMS({baremetal_service}, {storage_service}, "WMSHost"));
+
+    /* Associate the workflow to the WMS */
+    wms->addWorkflow(&workflow);
+
+    /* Instantiate a file registry service to be started on WMSHost. This service is
+     * essentially a replica catalog that stores <file , storage service> pairs so that
+     * any service, in particular a WMS, can discover where workflow files are stored. */
+    std::cerr << "Instantiating a FileRegistryService on WMSHost ..." << std::endl;
+    auto file_registry_service = new wrench::FileRegistryService("WMSHost");
+    simulation.add(file_registry_service);
+
+    /* It is necessary to store, or "stage", input files that only input. The getInputFiles()
+     * method of the Workflow class returns the set of all workflow files that are not generated
+     * by workflow tasks, and thus are only input files. These files are then staged on the storage service. */
+    std::cerr << "Staging task input files..." << std::endl;
+    for (auto const &f : workflow.getInputFiles()) {
+        simulation.stageFile(f, storage_service);
+    }
+
+    /* Launch the simulation. This call only returns when the simulation is complete. */
+    std::cerr << "Launching the Simulation..." << std::endl;
+    try {
+        simulation.launch();
+    } catch (std::runtime_error &e) {
+        std::cerr << "Exception: " << e.what() << std::endl;
+        return 1;
+    }
+    std::cerr << "Simulation done!" << std::endl;
+
+    /* Simulation results can be examined via simulation.output, which provides access to traces
+     * of events. In the code below, we print the  retrieve the trace of all task completion events, print how
+     * many such events there are, and print some information for the first such event. */
+    auto trace = simulation.getOutput().getTrace<wrench::SimulationTimestampTaskCompletion>();
+    for (auto const &item : trace) {
+        std::cerr << "Task "  << item->getContent()->getTask()->getID() << " completed at time " << item->getDate()  << std::endl;
+    }
+
+    return 0;
+}

examples/basic-examples/bare-metal-bag-of-tasks/CMakeLists.txt

@@ -0,0 +1,13 @@
+
+set(SOURCE_FILES
+        TwoTasksAtATimeWMS.h
+        TwoTasksAtATimeWMS.cpp
+        BareMetalBagOfTasks.cpp
+        )
+
+add_executable(wrench-bare-metal-bag-of-tasks-simulator ${SOURCE_FILES})
+
+target_link_libraries(wrench-bare-metal-bag-of-tasks-simulator wrench ${SimGrid_LIBRARY} ${PUGIXML_LIBRARY} ${LEMON_LIBRARY})
+
+install(TARGETS wrench-bare-metal-bag-of-tasks-simulator  DESTINATION bin)
+