source: DCWoRMS/trunk/src/example/localplugin/coolemall/recs/RECS_LB_SP.java @ 851

package example.localplugin.coolemall.recs;

import java.util.List;

import schedframe.events.scheduling.SchedulingEvent;
import schedframe.exceptions.ResourceException;
import schedframe.resources.UserResourceType;
import schedframe.resources.computing.ComputingResource;
import schedframe.resources.computing.recs.Node;
import schedframe.scheduling.manager.resources.ClusterResourceManager;
import schedframe.scheduling.manager.resources.ResourceManager;
import schedframe.scheduling.manager.tasks.JobRegistry;
import schedframe.scheduling.manager.tasks.JobRegistryImpl;
import schedframe.scheduling.plan.SchedulingPlanInterface;
import schedframe.scheduling.plan.impl.SchedulingPlan;
import schedframe.scheduling.plugin.grid.ModuleList;
import schedframe.scheduling.queue.TaskQueue;
import schedframe.scheduling.queue.TaskQueueList;
import schedframe.scheduling.tasks.TaskInterface;
import example.localplugin.BaseLocalSchedulingPlugin;
import gridsim.dcworms.DCWormsTags;

public class RECS_LB_SP extends BaseLocalSchedulingPlugin {

        public RECS_LB_SP () {
        }

        public SchedulingPlanInterface<?> schedule(SchedulingEvent event, TaskQueueList queues, JobRegistry jobRegistry,
                         ResourceManager resManager, ModuleList modules) {

                ClusterResourceManager resourceManager = (ClusterResourceManager) resManager;
                SchedulingPlan plan = new SchedulingPlan();
                // choose the events types to serve.
                // Different actions for different events are possible.
                switch (event.getType()) {
                case START_TASK_EXECUTION:
                case TASK_FINISHED:
                //case TIMER:
                        // our tasks are placed only in first queue (see
                        // BaseLocalSchedulingPlugin.placeJobsInQueues() method)
                        TaskQueue q = queues.get(0);
                        
                        // check all tasks in queue
                        for (int i = 0; i < q.size(); i++) {
                                TaskInterface<?> task = q.get(i);
                                // if status of the tasks in READY
                                if (task.getStatus() == DCWormsTags.READY) {

                                        String nodeName = chooseProvider(resourceManager);
                                        if (nodeName != null) {
                                                addToSchedulingPlan(plan, task, nodeName);
                                        }
                                }
                        }
                        break;
                }
                return plan;
        }

        @SuppressWarnings("unchecked")
        private String chooseProvider(ClusterResourceManager resourceManager) {
                List<ComputingResource> nodes = null;
                try {
                        nodes = (List<ComputingResource>) resourceManager.getResourcesOfType(new UserResourceType("Node"));
                } catch (ResourceException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
                int nodeIdx = findLeastLoadedResourceIdx(nodes);
                return nodes.get(nodeIdx).getName();
        }
        
        private int findLeastLoadedResourceIdx(List<ComputingResource> nodes ){
                int resourceIdx = -1;
                int minLoad = Integer.MAX_VALUE;
                
                for(int i = 0; i < nodes.size(); i++){
                        Node node = (Node) nodes.get(i);
                        JobRegistry jr = new JobRegistryImpl(node.getName());
                        int totalLoad = jr.getRunningTasks().size(); 
                        if(totalLoad < minLoad){
                                resourceIdx = i;
                                minLoad = totalLoad;
                        }
                }
                return resourceIdx;
        }

}