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// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.vespa.hosted.provision.autoscale;
import com.yahoo.config.provision.ClusterSpec;
import com.yahoo.vespa.hosted.provision.Node;
import com.yahoo.vespa.hosted.provision.NodeRepository;
import com.yahoo.vespa.hosted.provision.applications.Cluster;
import java.time.Instant;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.stream.Collectors;
/**
* A series of metric snapshots for all nodes in a cluster
*
* @author bratseth
*/
public class ClusterTimeseries {
private final List<Node> clusterNodes;
private final Map<String, Instant> startTimePerNode;
/** The measurements for all hosts in this snapshot */
private final List<NodeTimeseries> nodeTimeseries;
public ClusterTimeseries(Cluster cluster, List<Node> clusterNodes, NodeMetricsDb db, NodeRepository nodeRepository) {
this.clusterNodes = clusterNodes;
ClusterSpec.Type clusterType = clusterNodes.get(0).allocation().get().membership().cluster().type();
this.nodeTimeseries = db.getNodeTimeseries(nodeRepository.clock().instant().minus(Autoscaler.scalingWindow(clusterType)),
clusterNodes.stream().map(Node::hostname).collect(Collectors.toList()));
this.startTimePerNode = metricStartTimes(cluster, clusterNodes, nodeRepository);
}
/**
* Returns the instant of the oldest metric to consider for each node, or an empty map if metrics from the
* entire (max) window should be considered.
*/
private Map<String, Instant> metricStartTimes(Cluster cluster,
List<Node> clusterNodes,
NodeRepository nodeRepository) {
Map<String, Instant> startTimePerHost = new HashMap<>();
if ( ! cluster.scalingEvents().isEmpty()) {
var deployment = cluster.scalingEvents().get(cluster.scalingEvents().size() - 1);
for (Node node : clusterNodes) {
startTimePerHost.put(node.hostname(), nodeRepository.clock().instant()); // Discard all unless we can prove otherwise
var nodeGenerationMeasurements =
nodeTimeseries.stream().filter(m -> m.hostname().equals(node.hostname())).findAny();
if (nodeGenerationMeasurements.isPresent()) {
var firstMeasurementOfCorrectGeneration =
nodeGenerationMeasurements.get().asList().stream()
.filter(m -> m.generation() >= deployment.generation())
.findFirst();
if (firstMeasurementOfCorrectGeneration.isPresent()) {
startTimePerHost.put(node.hostname(), firstMeasurementOfCorrectGeneration.get().at());
}
}
}
}
return startTimePerHost;
}
/**
* Returns the average load of this resource in the measurement window,
* or empty if we are not in a position to make decisions from these measurements at this time.
*/
public Optional<Double> averageLoad(Resource resource) {
ClusterSpec.Type clusterType = clusterNodes.get(0).allocation().get().membership().cluster().type();
List<NodeTimeseries> currentMeasurements = filterStale(nodeTimeseries, startTimePerNode);
// Require a total number of measurements scaling with the number of nodes,
// but don't require that we have at least that many from every node
int measurementCount = currentMeasurements.stream().mapToInt(m -> m.size()).sum();
if (measurementCount / clusterNodes.size() < Autoscaler.minimumMeasurementsPerNode(clusterType)) return Optional.empty();
if (currentMeasurements.size() != clusterNodes.size()) return Optional.empty();
double measurementSum = currentMeasurements.stream().flatMap(m -> m.asList().stream()).mapToDouble(m -> value(resource, m)).sum();
return Optional.of(measurementSum / measurementCount);
}
private double value(Resource resource, MetricSnapshot snapshot) {
switch (resource) {
case cpu: return snapshot.cpu();
case memory: return snapshot.memory();
case disk: return snapshot.disk();
default: throw new IllegalArgumentException("Got an unknown resource " + resource);
}
}
private List<NodeTimeseries> filterStale(List<NodeTimeseries> timeseries,
Map<String, Instant> startTimePerHost) {
if (startTimePerHost.isEmpty()) return timeseries; // Map is either empty or complete
return timeseries.stream().map(m -> m.justAfter(startTimePerHost.get(m.hostname()))).collect(Collectors.toList());
}
}
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