ass3-elastic/src/main/java/dst/ass3/elastic/impl/ElasticityController.java

   1 package dst.ass3.elastic.impl;
   2
   3 import dst.ass3.elastic.ContainerException;
   4 import dst.ass3.elastic.ContainerInfo;
   5 import dst.ass3.elastic.IContainerService;
   6 import dst.ass3.elastic.IElasticityController;
   7 import dst.ass3.messaging.IWorkloadMonitor;
   8 import dst.ass3.messaging.RequestType;
   9
  10 import java.util.List;
  11 import java.util.Map;
  12
  13 public class ElasticityController implements IElasticityController {
  14     final static double alpha = 0.1;
  15     final static double omega = 0.05;
  16     private IContainerService containerService;
  17     private IWorkloadMonitor workloadMonitor;
  18
  19     public ElasticityController(IContainerService containerService, IWorkloadMonitor workloadMonitor) {
  20         this.containerService = containerService;
  21         this.workloadMonitor = workloadMonitor;
  22     }
  23
  24     @Override
  25     public void adjustWorkers() throws ContainerException {
  26         Map<RequestType, Long> workers = workloadMonitor.getWorkerCount();
  27         Map<RequestType, Long> reqs = workloadMonitor.getRequestCount();
  28         Map<RequestType, Double> avg = workloadMonitor.getAverageProcessingTime();
  29
  30         for (RequestType t : workers.keySet()) {
  31             // do weird math.
  32             double k = workers.get(t);
  33             double q = reqs.get(t);
  34             double r10 = avg.get(t);
  35             double rMax = (t == RequestType.VIDEO) ? 120000.0 : 30000.0; // 30 sec or 120 sec for videos.
  36
  37             double rExp = r10 * (double) q / k;
  38
  39             if (rExp > (rMax * (1.0 + alpha))) {
  40                 while (((r10 * q) / (k)) > rMax) {
  41                     //if (containerService.startWorker(t).isRunning()) k++; // FIXME: DOES NOT WORK - mock doesnt seem to return a valid container info.
  42                     containerService.startWorker(t);
  43                     k++;
  44                 }
  45             }
  46             if (rExp < (rMax * (1.0 - omega))) {
  47                 List<ContainerInfo> cl = containerService.listContainers();
  48                 while ((((r10 * q) / (k)) < rMax) && k > 0) {
  49                     for (ContainerInfo ci : cl) {
  50                         if (ci.getWorkerType() == t) {
  51                             containerService.stopContainer(ci.getContainerId());
  52                             k--;
  53                             break;
  54                         }
  55                     }
  56                 }
  57             }
  58         }
  59     }
  60 }