Added a new example (#157)

API changes/additions  for getting  workflow lists of tasks and files
Bug fix in JobManager

conf/cmake/Examples.cmake

@@ -2,6 +2,7 @@
 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
         )
 
 foreach (cmakefile ${EXAMPLES_CMAKEFILES_TXT})

examples/README.md

@@ -21,13 +21,16 @@ 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.
+    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```: A simulation of the execution of a 
-        chain workflow by a Workflow Management System on a compute service that has
-        scratch space to hold intermediate workflow files.
+  - ```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.
+     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. 
 

examples/basic-examples/bare-metal-chain-scratch/BareMetalChainScratch.cpp

@@ -0,0 +1,164 @@
+/**
+ * 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 chain workflow, that is, of a workflow
+ ** in which each task has at most a single parent and at most a single child:
+ **
+ **   File #0 -> Task #0 -> File #1 -> Task #1 -> File #2 -> .... -> Task #n-1 -> File #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-meta-chain-simulator 10 ./two_hosts.xml --wrench-no-logs --log=workflow_as_a_single_job_wms.threshold=info
+ **
+ ** Example invocation of the simulator for a 5-task workflow with full logging:
+ **    ./bare-meta-chain-simulator 5 ./two_hosts.xml
+ **/
+
+
+#include <iostream>
+#include <wrench.h>
+
+#include "WorkflowAsAsingleJobWMS.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;
+
+    /* Add workflow tasks */
+    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), 10000000000.0, 1, 10, 0.90, 10000000);
+    }
+
+    /* Add workflow files */
+    for (int i=0; i < num_tasks+1; i++) {
+        /* Create a 10MB file */
+        workflow.addFile("file_" + std::to_string(i), 10000000);
+    }
+
+    /* Set input/output files for each task */
+    for (int i=0; i < num_tasks; i++) {
+        auto task = workflow.getTaskByID("task_" + std::to_string(i));
+        task->addInputFile(workflow.getFileByID("file_" + std::to_string(i)));
+        task->addOutputFile(workflow.getFileByID("file_" + std::to_string(i + 1)));
+    }
+
+    /* 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 500M 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, "500000000"}}, {}));
+
+    /* 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 scratch storage space (mount point argument = "/scratch").
+     * This means that the WMS can opt to leave files in scratch. However, files in scratch are removed after
+     * a job completes */
+    std::cerr << "Instantiating a BareMetalComputeService on WMSHost..." << std::endl;
+    auto baremetal_service = simulation.add(new wrench::BareMetalComputeService(
+            "ComputeHost", {"ComputeHost"}, "/scratch/", {}, {}));
+
+    /* Instantiate a WMS, to be stated on WMSHost, which is responsible
+     * for executing the workflow. See comments in OneTaskAtATimeWMS.cpp
+     * for more details */
+    auto wms = simulation.add(
+            new wrench::WorkflowAsAsingleJobWMS({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-chain-scratch/CMakeLists.txt

@@ -0,0 +1,13 @@
+
+set(SOURCE_FILES
+        WorkflowAsAsingleJobWMS.h
+        WorkflowAsAsingleJobWMS.cpp
+        BareMetalChainScratch.cpp
+        )
+
+add_executable(wrench-bare-metal-chain-scratch-simulator ${SOURCE_FILES})
+
+target_link_libraries(wrench-bare-metal-chain-scratch-simulator wrench ${SimGrid_LIBRARY} ${PUGIXML_LIBRARY} ${LEMON_LIBRARY})
+
+install(TARGETS wrench-bare-metal-chain-scratch-simulator DESTINATION bin)
+

examples/basic-examples/bare-metal-chain-scratch/WorkflowAsAsingleJobWMS.cpp

@@ -0,0 +1,136 @@
+/**
+ * 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.
+ */
+
+/**
+ ** A Workflow Management System (WMS) implementation that operates as follows:
+ **  - While the workflow is not done, repeat:
+ **    - Pick a ready task if any
+ **    - Submit it to the first available BareMetalComputeService as a job in a way that
+ **       - Uses 5 cores
+ **       - Reads the input file from the StorageService
+ **       - Writes the output file from the StorageService
+ **/
+
+#include <iostream>
+
+#include "WorkflowAsAsingleJobWMS.h"
+
+XBT_LOG_NEW_DEFAULT_CATEGORY(workflow_as_a_single_job_wms, "Log category for WorkflowAsAsingleJobWMS");
+
+namespace wrench {
+
+    /**
+     * @brief Constructor, which calls the super constructor
+     *
+     * @param compute_services: a set of compute services available to run tasks
+     * @param storage_services: a set of storage services available to store files
+     * @param hostname: the name of the host on which to start the WMS
+     */
+    WorkflowAsAsingleJobWMS::WorkflowAsAsingleJobWMS(const std::set<std::shared_ptr<ComputeService>> &compute_services,
+                                                     const std::set<std::shared_ptr<StorageService>> &storage_services,
+                                                     const std::string &hostname) : WMS(
+            nullptr, nullptr,
+            compute_services,
+            storage_services,
+            {}, nullptr,
+            hostname,
+            "one-task-at-a-time") {}
+
+    /**
+     * @brief main method of the OneTaskAtATimeWMS daemon
+     *
+     * @return 0 on completion
+     *
+     * @throw std::runtime_error
+     */
+    int WorkflowAsAsingleJobWMS::main() {
+
+        /* Set the logging output to GREEN */
+        TerminalOutput::setThisProcessLoggingColor(TerminalOutput::COLOR_GREEN);
+
+        WRENCH_INFO("WMS starting on host %s", Simulation::getHostName().c_str());
+        WRENCH_INFO("About to execute a workflow with %lu tasks", this->getWorkflow()->getNumberOfTasks());
+
+        /* Create a job manager so that we can create/submit jobs */
+        auto job_manager = this->createJobManager();
+
+        /* Get the first available bare-metal compute service and storage servic  */
+        auto compute_service = *(this->getAvailableComputeServices<BareMetalComputeService>().begin());
+        auto storage_service = *(this->getAvailableStorageServices().begin());
+
+        /* We want to execute the workflow tasks so that intermediate files are
+         * kept in the compute service's scratch place, and only the final output
+         * file is written back to the storage service at host WMSHost. However,
+         * files stored in the compute service's scratch space are erased
+         * after the job that created them has completed. So we ave the run
+         * the entire workflow as a single multi-task job! */
+
+        /* First, we need to create a map of file locations, stating for each file
+         * where is should be read/written */
+        std::map<WorkflowFile *, std::shared_ptr<FileLocation>> file_locations;
+        // Set each file's location to the compute service's scratch space
+        for (auto const &file : this->getWorkflow()->getFiles()) {
+            file_locations[file] = FileLocation::SCRATCH;
+        }
+        // For the workflow input files, in fact, set the location to the storage service
+        for (auto const &f  : this->getWorkflow()->getInputFiles()) {
+            file_locations[f] = FileLocation::LOCATION(storage_service);
+        }
+        // For the workflow output files, in fact, set the location to the storage service
+        for (auto const &f  : this->getWorkflow()->getOutputFiles()) {
+            file_locations[f] = FileLocation::LOCATION(storage_service);
+        }
+
+        /* Second, we create a job */
+        auto job = job_manager->createStandardJob(this->getWorkflow()->getTasks(), file_locations);
+
+        /* Submit the job to the compute service */
+        job_manager->submitJob(job, compute_service);
+
+        /* Wait for a workflow execution event and process it. In this case we know that
+         * the event will be a StandardJobCompletionEvent, which is processed by the method
+         * processEventStandardJobCompletion() that this class overrides. */
+        this->waitForAndProcessNextEvent();
+
+        WRENCH_INFO("Workflow execution complete");
+        return 0;
+    }
+
+    /**
+     * @brief Process a standard job completion event
+     *
+     * @param event: the event
+     */
+    void WorkflowAsAsingleJobWMS::processEventStandardJobCompletion(std::shared_ptr<StandardJobCompletedEvent> event) {
+        /* Retrieve the job that this event is for */
+        auto job = event->standard_job;
+        /* Retrieve the job's first (and in our case only) task */
+        auto task = job->getTasks().at(0);
+        WRENCH_INFO("Notified that a standard job has completed task %s", task->getID().c_str());
+    }
+
+    /**
+     * @brief Process a standard job failure event
+     *
+     * @param event: the event
+     */
+    void WorkflowAsAsingleJobWMS::processEventStandardJobFailure(std::shared_ptr<StandardJobFailedEvent> event) {
+        /* Retrieve the job that this event is for */
+        auto job = event->standard_job;
+        /* Retrieve the job's first (and in our case only) task */
+        auto task = job->getTasks().at(0);
+        /* Print some error message */
+        WRENCH_INFO("Notified that a standard job has failed for task %s with error %s",
+                    task->getID().c_str(),
+                    event->failure_cause->toString().c_str());
+        throw std::runtime_error("ABORTING DUE TO JOB FAILURE");
+    }
+
+
+}

examples/basic-examples/bare-metal-chain-scratch/WorkflowAsAsingleJobWMS.h

@@ -0,0 +1,45 @@
+/**
+ * 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.
+ */
+
+
+#ifndef WRENCH_ONE_TASK_AT_A_TIME_SCRATCH_H
+#define WRENCH_ONE_TASK_AT_A_TIME_SCRATCH_H
+
+#include <wrench-dev.h>
+
+
+namespace wrench {
+
+    class Simulation;
+
+    /**
+     *  @brief A Workflow Management System (WMS) implementation (inherits from WMS)
+     */
+    class WorkflowAsAsingleJobWMS : public WMS {
+
+    public:
+        // Constructor
+        WorkflowAsAsingleJobWMS(
+                  const std::set<std::shared_ptr<ComputeService>> &compute_services,
+                  const std::set<std::shared_ptr<StorageService>> &storage_services,
+                  const std::string &hostname);
+
+    protected:
+
+        // Overriden methods
+        void processEventStandardJobCompletion(std::shared_ptr<StandardJobCompletedEvent>) override;
+        void processEventStandardJobFailure(std::shared_ptr<StandardJobFailedEvent>) override;
+
+    private:
+        // main() method of the WMS
+        int main() override;
+
+    };
+}
+#endif //WRENCH_ONE_TASK_AT_A_TIME_SCRATCH_H