Description: Processing tuples in iFogSim involves intercepting and handling data packets or events that represent computations or messages exchanged between devices in the fog environment. Tuples arrive at fog devices as part of a simulation workflow, carrying specific data types and associated attributes such as source, destination, and processing requirements. A processTupleArrival method, often customized for individual applications, determines how a fog device should handle these tuples. This method typically involves identifying the tuple's type to apply appropriate processing logic. For instance, tuples categorized as "CAMERA" may trigger video analysis, while "MOTION_VIDEO_STREAM" could initiate video streaming processes. Depending on the application logic, tuples might be forwarded to other devices, such as parent nodes or actuators, or processed locally. The tuple's direction (upstream or downstream) influences whether it moves towards centralized servers or downstream devices. Developers implement specific logic to handle tuples based on their characteristics and desired outcomes, ensuring that the fog device collaborates effectively within the distributed system.
Sample Code
package fogsamples;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.LinkedList;
import java.util.List;
import org.cloudbus.cloudsim.Host;
import org.cloudbus.cloudsim.Log;
import org.cloudbus.cloudsim.Pe;
import org.cloudbus.cloudsim.Storage;
import org.cloudbus.cloudsim.core.CloudSim;
import org.cloudbus.cloudsim.core.SimEvent;
import org.cloudbus.cloudsim.power.PowerHost;
import org.cloudbus.cloudsim.provisioners.RamProvisionerSimple;
import org.cloudbus.cloudsim.sdn.overbooking.BwProvisionerOverbooking;
import org.cloudbus.cloudsim.sdn.overbooking.PeProvisionerOverbooking;
import org.fog.application.AppEdge;
import org.fog.application.AppLoop;
import org.fog.application.Application;
import org.fog.application.selectivity.FractionalSelectivity;
import org.fog.entities.Actuator;
import org.fog.entities.FogBroker;
import org.fog.entities.FogDevice;
import org.fog.entities.FogDeviceCharacteristics;
import org.fog.entities.Sensor;
import org.fog.entities.Tuple;
import org.fog.placement.Controller;
import org.fog.placement.ModuleMapping;
import org.fog.placement.ModulePlacementEdgewards;
import org.fog.placement.ModulePlacementMapping;
import org.fog.policy.AppModuleAllocationPolicy;
import org.fog.scheduler.StreamOperatorScheduler;
import org.fog.utils.FogLinearPowerModel;
import org.fog.utils.FogUtils;
import org.fog.utils.TimeKeeper;
import org.fog.utils.distribution.DeterministicDistribution;
public class TupleProcessing {
static List fogDevices = new ArrayList();
static List sensors = new ArrayList();
static List actuators = new ArrayList();
static int numOfAreas = 1;
static int numOfCamerasPerArea = 4;
private static boolean CLOUD = false;
public static void main(String[] args) {
Log.printLine("Starting TupleProcessing...");
try {
Log.disable();
int num_user = 1; // number of cloud users
Calendar calendar = Calendar.getInstance();
boolean trace_flag = false; // mean trace events
CloudSim.init(num_user, calendar, trace_flag);
String appId = "dcns"; // identifier of the application
FogBroker broker = new FogBroker("broker");
Application application = createApplication(appId, broker.getId());
application.setUserId(broker.getId());
createFogDevices(broker.getId(), appId);
Controller controller = null;
ModuleMapping moduleMapping = ModuleMapping.createModuleMapping(); // initializing a module mapping
for (FogDevice device : fogDevices) {
if (device.getName().startsWith("m")) { // names of all Smart Cameras start with 'm'
moduleMapping.addModuleToDevice("motion_detector", device.getName()); // fixing 1 instance of the Motion Detector module to each Smart Camera
}
}
moduleMapping.addModuleToDevice("user_interface", "cloud"); // fixing instances of User Interface module in the Cloud
if (CLOUD) {
// if the mode of deployment is cloud-based
moduleMapping.addModuleToDevice("object_detector", "cloud"); // placing all instances of Object Detector module in the Cloud moduleMapping.addModuleToDevice("object_tracker", "cloud"); // placing all instances of Object Tracker module in the Cloud }
controller = new Controller("master-controller", fogDevices, sensors, actuators);
controller.submitApplication(application, (CLOUD) ? (new ModulePlacementMapping(fogDevices, application, moduleMapping)) : (new ModulePlacementEdgewards(fogDevices, sensors, actuators, application, moduleMapping)));
// You can add more conditions and custom processing for different tuple types here. }
/** * Creates the fog devices in the physical topology of the simulation. * * @param userId * @param appId */ private static void createFogDevices(int userId, String appId) { FogDevice cloud = createFogDevice("cloud", 44800, 40000, 100, 10000, 0, 0.01, 16 * 103, 16 * 83.25); cloud.setParentId(-1); fogDevices.add(cloud); FogDevice proxy = createFogDevice("proxy-server", 2800, 4000, 10000, 10000, 1, 0.0, 107.339, 83.4333); proxy.setParentId(cloud.getId()); proxy.setUplinkLatency(100); // latency of connection between proxy server and cloud is 100 ms fogDevices.add(proxy); for (int i = 0; i < numOfAreas; i++) { addArea(i + "", userId, appId, proxy.getId()); } }
private static FogDevice addArea(String id, int userId, String appId, int parentId) { FogDevice router = createFogDevice("d-" + id, 2800, 4000, 10000, 10000, 1, 0.0, 107.339, 83.4333); fogDevices.add(router); router.setUplinkLatency(2); // latency of connection between router and proxy server is 2 ms for (int i = 0; i < numOfCamerasPerArea; i++) { String mobileId = id + "-" + i; FogDevice camera = addCamera(mobileId, userId, appId, router.getId()); // adding a smart camera to the physical topology. Smart cameras have been modeled as fog devices as well. camera.setUplinkLatency(2); // latency of connection between camera and router is 2 ms fogDevices.add(camera); } router.setParentId(parentId); return router; }
private static FogDevice addCamera(String id, int userId, String appId, int parentId) { FogDevice camera = createFogDevice("m-" + id, 500, 1000, 10000, 10000, 3, 0, 87.53, 82.44); camera.setParentId(parentId); Sensor sensor = new Sensor("s-" + id, "CAMERA", userId, appId, new DeterministicDistribution(5)); // inter-transmission time of camera (sensor) follows a deterministic distribution sensors.add(sensor); Actuator ptz = new Actuator("ptz-" + id, userId, appId, "PTZ_CONTROL"); actuators.add(ptz); sensor.setGatewayDeviceId(camera.getId()); sensor.setLatency(1.0); // latency of connection between camera (sensor) and the parent Smart Camera is 1 ms ptz.setGatewayDeviceId(camera.getId()); ptz.setLatency(1.0); // latency of connection between PTZ Control and the parent Smart Camera is 1 ms return camera; }
/** * Creates a vanilla fog device * * @param nodeName name of the device to be used in simulation * @param mips MIPS * @param ram RAM * @param upBw uplink bandwidth * @param downBw downlink bandwidth * @param level hierarchy level of the device * @param ratePerMips cost rate per MIPS used * @param busyPower * @param idlePower * @return */ private static FogDevice createFogDevice(String nodeName, long mips, int ram, long upBw, long downBw, int level, double ratePerMips, double busyPower, double idlePower) {
List peList = new ArrayList();
// 3. Create PEs and add these into a list. peList.add(new Pe(0, new PeProvisionerOverbooking(mips))); // need to store Pe id and MIPS Rating
int hostId = FogUtils.generateEntityId(); long storage = 1000000; // host storage int bw = 10000;
PowerHost host = new PowerHost( hostId, new RamProvisionerSimple(ram), new BwProvisionerOverbooking(bw), storage, peList, new StreamOperatorScheduler(peList), new FogLinearPowerModel(busyPower, idlePower) );
List hostList = new ArrayList(); hostList.add(host);
String arch = "x86"; // system architecture String os = "Linux"; // operating system String vmm = "Xen"; double time_zone = 10.0; // time zone this resource located double cost = 3.0; // the cost of using processing in this resource double costPerMem = 0.05; // the cost of using memory in this resource double costPerStorage = 0.001; // the cost of using storage in this // resource double costPerBw = 0.0; // the cost of using bw in this resource LinkedList storageList = new LinkedList(); // we are not adding SAN // devices by now
/** * Function to create the Intelligent Surveillance application in the DDF * model. * * @param appId unique identifier of the application * @param userId identifier of the user of the application * @return */ @SuppressWarnings({"serial"}) private static Application createApplication(String appId, int userId) {
Application application = Application.createApplication(appId, userId); /* * Adding modules (vertices) to the application model (directed graph) */ application.addAppModule("object_detector", 10); application.addAppModule("motion_detector", 10); application.addAppModule("object_tracker", 10); application.addAppModule("user_interface", 10);
/*
* Connecting the application modules (vertices) in the application model (directed graph) with edges
*/
application.addAppEdge("CAMERA", "motion_detector", 1000, 20000, "CAMERA", Tuple.UP, AppEdge.SENSOR); // adding edge from CAMERA (sensor) to Motion Detector module carrying tuples of type CAMERA
application.addAppEdge("motion_detector", "object_detector", 2000, 2000, "MOTION_VIDEO_STREAM", Tuple.UP, AppEdge.MODULE); // adding edge from Motion Detector to Object Detector module carrying tuples of type MOTION_VIDEO_STREAM
application.addAppEdge("object_detector", "user_interface", 500, 2000, "DETECTED_OBJECT", Tuple.UP, AppEdge.MODULE); // adding edge from Object Detector to User Interface module carrying tuples of type DETECTED_OBJECT
application.addAppEdge("object_detector", "object_tracker", 1000, 100, "OBJECT_LOCATION", Tuple.UP, AppEdge.MODULE); // adding edge from Object Detector to Object Tracker module carrying tuples of type OBJECT_LOCATION
application.addAppEdge("object_tracker", "PTZ_CONTROL", 100, 28, 100, "PTZ_PARAMS", Tuple.DOWN, AppEdge.ACTUATOR); // adding edge from Object Tracker to PTZ CONTROL (actuator) carrying tuples of type PTZ_PARAMS
/*
* Defining the input-output relationships (represented by selectivity) of the application modules.
*/
application.addTupleMapping("motion_detector", "CAMERA", "MOTION_VIDEO_STREAM", new FractionalSelectivity(1.0)); // 1.0 tuples of type MOTION_VIDEO_STREAM are emitted by Motion Detector module per incoming tuple of type CAMERA
application.addTupleMapping("object_detector", "MOTION_VIDEO_STREAM", "OBJECT_LOCATION", new FractionalSelectivity(1.0)); // 1.0 tuples of type OBJECT_LOCATION are emitted by Object Detector module per incoming tuple of type MOTION_VIDEO_STREAM
application.addTupleMapping("object_detector", "MOTION_VIDEO_STREAM", "DETECTED_OBJECT", new FractionalSelectivity(0.05)); // 0.05 tuples of type MOTION_VIDEO_STREAM are emitted by Object Detector module per incoming tuple of type MOTION_VIDEO_STREAM
/*
* Defining application loops (maybe incomplete loops) to monitor the latency of.
* Here, we add two loops for monitoring : Motion Detector -> Object Detector -> Object Tracker and Object Tracker -> PTZ Control
*/
final AppLoop loop1 = new AppLoop(new ArrayList() {
{
add("motion_detector");
add("object_detector");
add("object_tracker");
}
});
final AppLoop loop2 = new AppLoop(new ArrayList() {
{
add("object_tracker");
add("PTZ_CONTROL");
}
});
List loops = new ArrayList() {
{
add(loop1);
add(loop2);
}
};
application.setLoops(loops);
return application;
}
}
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