Pavlin Radoslavov | 41d5adb | 2014-10-23 13:44:21 -0700 | [diff] [blame] | 1 | package org.onlab.metrics; |
| 2 | |
| 3 | import com.codahale.metrics.Gauge; |
| 4 | import com.codahale.metrics.Meter; |
| 5 | |
| 6 | /** |
| 7 | * Metric measurements for events. |
| 8 | */ |
| 9 | public class EventMetric { |
| 10 | private static final String GAUGE_TIMESTAMP_NAME = "Timestamp.EpochMs"; |
| 11 | private static final String METER_RATE_NAME = "Rate"; |
| 12 | |
| 13 | private final MetricsService metricsService; |
| 14 | private final String componentName; |
| 15 | private final String featureName; |
| 16 | |
| 17 | private MetricsComponent metricsComponent; |
| 18 | private MetricsFeature metricsFeature; |
| 19 | |
| 20 | private volatile long lastEventTimestampEpochMs = 0; |
| 21 | private Gauge<Long> lastEventTimestampGauge; |
| 22 | private Meter eventRateMeter; |
| 23 | |
| 24 | /** |
| 25 | * Constructor. |
| 26 | * |
| 27 | * @param metricsService the Metrics Service to use for Metrics |
| 28 | * registration and deregistration |
| 29 | * @param componentName the Metrics Component Name to use for Metrics |
| 30 | * registration and deregistration |
| 31 | * @param featureName the Metrics Feature Name to use for Metrics |
| 32 | * registration and deregistration |
| 33 | */ |
| 34 | public EventMetric(MetricsService metricsService, String componentName, |
| 35 | String featureName) { |
| 36 | this.metricsService = metricsService; |
| 37 | this.componentName = componentName; |
| 38 | this.featureName = featureName; |
| 39 | } |
| 40 | |
| 41 | /** |
| 42 | * Registers the metrics. |
| 43 | */ |
| 44 | public void registerMetrics() { |
| 45 | metricsComponent = metricsService.registerComponent(componentName); |
| 46 | metricsFeature = metricsComponent.registerFeature(featureName); |
| 47 | |
| 48 | lastEventTimestampEpochMs = 0; |
| 49 | lastEventTimestampGauge = |
| 50 | metricsService.registerMetric(metricsComponent, |
| 51 | metricsFeature, |
| 52 | GAUGE_TIMESTAMP_NAME, |
| 53 | new Gauge<Long>() { |
| 54 | @Override |
| 55 | public Long getValue() { |
| 56 | return lastEventTimestampEpochMs; |
| 57 | } |
| 58 | }); |
| 59 | |
| 60 | eventRateMeter = metricsService.createMeter(metricsComponent, |
| 61 | metricsFeature, |
| 62 | METER_RATE_NAME); |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Removes the metrics. |
| 67 | */ |
| 68 | public void removeMetrics() { |
| 69 | lastEventTimestampEpochMs = 0; |
| 70 | metricsService.removeMetric(metricsComponent, |
| 71 | metricsFeature, |
| 72 | GAUGE_TIMESTAMP_NAME); |
| 73 | metricsService.removeMetric(metricsComponent, |
| 74 | metricsFeature, |
| 75 | METER_RATE_NAME); |
| 76 | } |
| 77 | |
| 78 | /** |
| 79 | * Updates the metric measurements for a single event. |
| 80 | */ |
| 81 | public void eventReceived() { |
| 82 | lastEventTimestampEpochMs = System.currentTimeMillis(); |
| 83 | eventRateMeter.mark(1); |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Gets the last event timestamp Gauge (ms from the Epoch). |
| 88 | * |
| 89 | * @return the last event timestamp Gauge (ms from the Epoch) |
| 90 | */ |
| 91 | public Gauge<Long> lastEventTimestampGauge() { |
| 92 | return lastEventTimestampGauge; |
| 93 | } |
| 94 | |
| 95 | /** |
| 96 | * Gets the event rate meter. |
| 97 | * |
| 98 | * @return the event rate meter |
| 99 | */ |
| 100 | public Meter eventRateMeter() { |
| 101 | return eventRateMeter; |
| 102 | } |
| 103 | } |