Merge pull request #41 from Cinimex-Informatica/feature/issue32_smart_gauge

issue32 Resolves:#32 ExtremeGauges added, typo in readme fixed.

Author: sberdyshev

README.md

@@ -137,7 +137,7 @@ The only input parameter is the path to your configuration file.
 <td><strong>Prometheus metric name</strong></td>
 <td><strong>Metric type</strong></td>
 <td><strong>Short description</strong></td>
-<td><strong>MQ metric elemen</strong></td>
+<td><strong>MQ metric element</strong></td>
 </tr>
 <tr>
 <td>system_cpu_user_cpu_time_percentage</td>

pom.xml

@@ -54,7 +54,7 @@
         </dependency>
     </dependencies>
     <build>
-        <finalName>webspheremq_exporter</finalName>
+        <finalName>mq_exporter</finalName>
         <plugins>
             <!-- Set a JDK compiler level -->
             <plugin>

src/main/java/ru/cinimex/exporter/prometheus/HTTPServer.java

@@ -7,7 +7,7 @@
 import io.prometheus.client.exporter.common.TextFormat;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import ru.cinimex.exporter.ExporterLauncher;
+import ru.cinimex.exporter.prometheus.metrics.MetricsManager;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -149,6 +149,7 @@ public void handle(HttpExchange t) throws IOException {
             }
             t.close();
             logger.debug("Data was sent to Prometheus.");
+            MetricsManager.notifyMetricsWereScraped();
         }
 
     }

src/main/java/ru/cinimex/exporter/prometheus/metrics/ExtremeGauge.java

@@ -0,0 +1,55 @@
+package ru.cinimex.exporter.prometheus.metrics;
+
+import io.prometheus.client.Gauge;
+import ru.cinimex.exporter.prometheus.Registry;
+
+/**
+ * Represents custom Prometheus metric. Counter, which can increase and decrease. Used to store max or min value
+ * between Prometheus scrapes.
+ */
+public class ExtremeGauge implements MetricInterface {
+    private Gauge gauge;
+    private boolean storeMax;
+    private volatile boolean wasScraped = true;
+
+    /**
+     * ExtremeGauge constructor.
+     *
+     * @param metricName    - metric name.
+     * @param metricInfo    - metric info (description).
+     * @param storeMaxValue - true, if gauge should keep max value between scrapes, false otherwise.
+     * @param labelNames    - labels.
+     */
+    public ExtremeGauge(String metricName, String metricInfo, boolean storeMaxValue, String... labelNames) {
+        this.storeMax = storeMaxValue;
+        gauge = Gauge.build().name(metricName).help(metricInfo).labelNames(labelNames).register(Registry.getRegistry());
+    }
+
+    /**
+     * Sets gauge to exact value.
+     *
+     * @param value       - new value.
+     * @param labelValues - value labels.
+     */
+    private void setGauge(double value, String... labelValues) {
+        gauge.labels(labelValues).set(value);
+    }
+
+    @Override
+    public synchronized void update(double value, String... labels) {
+        double currentValue = gauge.labels(labels).get();
+        if (wasScraped) {
+            setGauge(value, labels);
+            wasScraped = false;
+        } else if (storeMax && value > currentValue) {
+            setGauge(value, labels);
+        } else if (!storeMax && value < currentValue) {
+            setGauge(value, labels);
+        }
+    }
+
+    @Override
+    public void notifyWasScraped() {
+        wasScraped = true;
+    }
+}

src/main/java/ru/cinimex/exporter/prometheus/metrics/MetricInterface.java

@@ -7,9 +7,16 @@ public interface MetricInterface {
 
     /**
      * Method should contain all logic about updating exact metric.
-     * @param value - incoming value.
+     *
+     * @param value  - incoming value.
      * @param labels - incoming labels.
      */
     void update(double value, String... labels);
 
+    /**
+     * Method should contain additional processing for metric, when it was scraped by Prometheus.
+     * Leave empty, if there is no need to do anything after metric was scraped.
+     */
+    void notifyWasScraped();
+
 }

src/main/java/ru/cinimex/exporter/prometheus/metrics/MetricsManager.java

@@ -46,6 +46,16 @@ public static void initMetrics(ArrayList<PCFElement> elements, ArrayList<MQObjec
                         metrics.put(metricName, metric);
                         logger.trace("New counter created! Name: {}, description: {}, labels: {}.", metricName, row.getRowDesc(), labels);
                         break;
+                    case ExtremeGaugeMax:
+                        metric = new ExtremeGauge(metricName, row.getRowDesc(), true, labels.stream().toArray(String[]::new));
+                        metrics.put(metricName, metric);
+                        logger.trace("New extreme gauge created! Name: {}, description: {}, labels: {}.", metricName, row.getRowDesc(), labels);
+                        break;
+                    case ExtremeGaugeMin:
+                        metric = new ExtremeGauge(metricName, row.getRowDesc(), false, labels.stream().toArray(String[]::new));
+                        metrics.put(metricName, metric);
+                        logger.trace("New extreme gauge created! Name: {}, description: {}, labels: {}.", metricName, row.getRowDesc(), labels);
+                        break;
                     default:
                         logger.error("Error during metrics initialization: Unknown metric type! Make sure it is one " + "of: {}", MetricsReference.Metric.Type.values());
                 }
@@ -70,6 +80,15 @@ public static void updateMetric(String metricName, Double value, String... label
         metrics.get(metricName).update(value, labels);
     }
 
+    /**
+     * Notifies all metrics after each Prometheus scrape.
+     */
+    public static void notifyMetricsWereScraped() {
+        for (MetricInterface metric : metrics.values()) {
+            metric.notifyWasScraped();
+        }
+    }
+
     /**
      * Contains all possible labels
      */

src/main/java/ru/cinimex/exporter/prometheus/metrics/MetricsReference.java

@@ -88,10 +88,10 @@ public class MetricsReference {
             put("Subscription delete failure count", new Metric("mq_subscribe_subscription_delete_failure_count_totalcalls", Metric.Type.SimpleCounter));
             put("MQSUBRQ count", new Metric("mq_subscribe_mqsubrq_count_totalcalls", Metric.Type.SimpleCounter));
             put("Failed MQSUBRQ count", new Metric("mq_subscribe_failed_mqsubrq_count_totalcalls", Metric.Type.SimpleCounter));
-            put("Durable subscriber - high water mark", new Metric("mq_subscribe_durable_subscriber_high_water_mark_subscriptions", Metric.Type.SimpleGauge));
-            put("Durable subscriber - low water mark", new Metric("mq_subscribe_durable_subscriber_low_water_mark_subscriptions", Metric.Type.SimpleGauge));
-            put("Non-durable subscriber - high water mark", new Metric("mq_subscribe_non_durable_subscriber_high_water_mark_subscriptions", Metric.Type.SimpleGauge));
-            put("Non-durable subscriber - low water mark", new Metric("mq_subscribe_non_durable_subscriber_low_water_mark_subscriptions", Metric.Type.SimpleGauge));
+            put("Durable subscriber - high water mark", new Metric("mq_subscribe_durable_subscriber_high_water_mark_subscriptions", Metric.Type.ExtremeGaugeMax));
+            put("Durable subscriber - low water mark", new Metric("mq_subscribe_durable_subscriber_low_water_mark_subscriptions", Metric.Type.ExtremeGaugeMin));
+            put("Non-durable subscriber - high water mark", new Metric("mq_subscribe_non_durable_subscriber_high_water_mark_subscriptions", Metric.Type.ExtremeGaugeMax));
+            put("Non-durable subscriber - low water mark", new Metric("mq_subscribe_non_durable_subscriber_low_water_mark_subscriptions", Metric.Type.ExtremeGaugeMin));
             put("Topic MQPUT/MQPUT1 interval total", new Metric("mq_publish_topic_mqput_mqput1_interval_total_totalmessages", Metric.Type.SimpleCounter));
             put("Interval total topic bytes put", new Metric("mq_publish_interval_total_topic_bytes_put_totalbytes", Metric.Type.SimpleCounter));
             put("Published to subscribers - message count", new Metric("mq_publish_published_to_subscribers_message_count_totalmessages", Metric.Type.SimpleCounter));
@@ -289,7 +289,7 @@ public Metric(String name, Type type) {
         }
 
         public enum Type {
-            SimpleCounter, SimpleGauge
+            SimpleCounter, SimpleGauge, ExtremeGaugeMin, ExtremeGaugeMax
         }
     }
 }

src/main/java/ru/cinimex/exporter/prometheus/metrics/SimpleCounter.java

@@ -11,6 +11,7 @@ public class SimpleCounter implements MetricInterface {
 
     /**
      * Counter constructor.
+     *
      * @param metricName - metric name.
      * @param metricInfo - metric info (description).
      * @param labelNames - labels.
@@ -35,4 +36,8 @@ private void incCounter(double value, String... labelValues) {
     public void update(double value, String... labels) {
         incCounter(value, labels);
     }
+
+    @Override
+    public void notifyWasScraped() {
+    }
 }

src/main/java/ru/cinimex/exporter/prometheus/metrics/SimpleGauge.java

@@ -35,6 +35,9 @@ private void setGauge(double value, String... labelValues) {
     @Override
     public void update(double value, String... labels) {
         setGauge(value, labels);
+    }
 
+    @Override
+    public void notifyWasScraped() {
     }
 }