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Implement ElasticityController (3.2.4)

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This commit is contained in:
Tobias Eidelpes 2021-05-19 10:56:43 +02:00
parent ae25560fb5
commit 33d061cbef
2 changed files with 78 additions and 2 deletions
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77
ass3-elastic/src/main/java/dst/ass3/elastic/impl/ElasticityController.java Normal file
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@ -0,0 +1,77 @@
package dst.ass3.elastic.impl;
import dst.ass3.elastic.ContainerException;
import dst.ass3.elastic.ContainerInfo;
import dst.ass3.elastic.IContainerService;
import dst.ass3.elastic.IElasticityController;
import dst.ass3.messaging.IWorkloadMonitor;
import dst.ass3.messaging.Region;
import java.util.List;
import java.util.stream.Collectors;
public class ElasticityController implements IElasticityController {
IContainerService containerService;
IWorkloadMonitor workloadMonitor;
final double alpha = 0.1; // scale-out threshold
final double omega = 0.05; // scale-down threshold
public ElasticityController(IContainerService containerService, IWorkloadMonitor workloadMonitor) {
this.containerService = containerService;
this.workloadMonitor = workloadMonitor;
}
@Override
public void adjustWorkers() throws ContainerException {
long[] k = new long[3]; // number of workers per region currently running
long[] q = new long[3]; // number of waiting requests per region
double[] r10 = new double[3]; // avg processing time of last 10 requests per region
int[] rMax = new int[3]; // defined max wait time for request per region
double[] rExp = new double[3]; // expected wait time for last request in queue per region
rMax[0] = 30 * 1000; // max wait time of at_vienna in milliseconds
rMax[1] = 30 * 1000; // max wait time of at_linz in milliseconds
rMax[2] = 120 * 1000; // max wait time of de_berlin in milliseconds
k[0] = workloadMonitor.getWorkerCount().get(Region.AT_VIENNA);
k[1] = workloadMonitor.getWorkerCount().get(Region.AT_LINZ);
k[2] = workloadMonitor.getWorkerCount().get(Region.DE_BERLIN);
q[0] = workloadMonitor.getRequestCount().get(Region.AT_VIENNA);
q[1] = workloadMonitor.getRequestCount().get(Region.AT_LINZ);
q[2] = workloadMonitor.getRequestCount().get(Region.DE_BERLIN);
r10[0] = workloadMonitor.getAverageProcessingTime().get(Region.AT_VIENNA);
r10[1] = workloadMonitor.getAverageProcessingTime().get(Region.AT_LINZ);
r10[2] = workloadMonitor.getAverageProcessingTime().get(Region.DE_BERLIN);
for (int i = 0; i < 3; i++) {
rExp[i] = (q[i] * r10[i]) / k[i];
if (rExp[i] > rMax[i] * (1 + alpha)) {
// rExp exceeds scale-out threshold
// Calculate workers needed to get back to rMax
double workersNeeded = (q[i] * r10[i]) / rMax[i] - k[i];
System.out.println("Scaling up " + workersNeeded + " " + Region.values()[i] + " workers");
for (int j = 0; j < workersNeeded; j++) {
ContainerInfo containerInfo = containerService.startWorker(Region.values()[i]);
}
} else if (rExp[i] < rMax[i] * (1 - omega)) {
// rExp exceeds scale-down threshold
// Calculate how many workers should be stopped to get back to rMax
double workersStop = ((q[i] * r10[i]) / rMax[i] - k[i]) * (-1);
System.out.println("Scaling down " + workersStop + " " + Region.values()[i] + " workers");
List<ContainerInfo> containers = containerService.listContainers();
for (int j = 0; j < workersStop; j++) {
Region currentRegion = Region.values()[i];
List<ContainerInfo> containersToRemove = containers.stream()
.filter(containerInfo -> containerInfo.getWorkerRegion().equals(currentRegion))
.collect(Collectors.toList());
containerService.stopContainer(containersToRemove.get(0).getContainerId());
}
}
}
}
}

3
ass3-elastic/src/main/java/dst/ass3/elastic/impl/ElasticityFactory.java
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@ -16,8 +16,7 @@ public class ElasticityFactory implements IElasticityFactory {
@Override
public IElasticityController createElasticityController(IContainerService containerService,
IWorkloadMonitor workloadMonitor) {
// TODO
return null;
return new ElasticityController(containerService, workloadMonitor);
}
}