Moved QuaDer metrics exporter to Singleton

quads-loader/src/main/java/fr/vcity/converg/MetricsSingleton.java

@@ -0,0 +1,74 @@
+package fr.vcity.converg;
+
+import io.prometheus.metrics.core.metrics.Counter;
+import io.prometheus.metrics.core.metrics.Summary;
+import io.prometheus.metrics.model.snapshots.Unit;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Objects;
+
+public class MetricsSingleton {
+
+    private static final Logger log = LoggerFactory.getLogger(MetricsSingleton.class);
+
+    private static MetricsSingleton metricsSingleton;
+
+    public Counter counterVersionTotal;
+
+    public Summary summaryVersionBatchingDuration;
+
+    public Summary summaryVersionCatalogDuration;
+
+    public Summary summaryVersionCondensingDuration;
+
+    /**
+     * Constructor method in order to create db connection & statement
+     */
+    private MetricsSingleton() {
+        counterVersionTotal =
+                Counter.builder()
+                        .name("version_count_total")
+                        .help("number of version that have been imported in the database")
+                        .register();
+
+        summaryVersionBatchingDuration =
+                Summary.builder()
+                        .name("file_at_version_batching_duration_seconds")
+                        .help("duration of the file batching in seconds at a certain version")
+                        .unit(Unit.SECONDS)
+                        .labelNames("filename", "version")
+                        .register();
+
+        summaryVersionCatalogDuration =
+                Summary.builder()
+                        .name("file_at_version_catalog_duration_seconds")
+                        .help("duration of the file catalog in seconds at a certain version")
+                        .unit(Unit.SECONDS)
+                        .labelNames("filename", "version")
+                        .register();
+
+        summaryVersionCondensingDuration =
+                Summary.builder()
+                        .name("file_at_version_condensing_duration_seconds")
+                        .help("duration of the file condensing in seconds at a certain version")
+                        .unit(Unit.SECONDS)
+                        .labelNames("filename", "version")
+                        .register();
+    }
+
+    /**
+     * Create the instance of {@link MetricsSingleton} object if it is not created yet and guarantee that there is only one single instance is created for this class.
+     *
+     * @return MetricsSingleton created single instance
+     */
+    public static MetricsSingleton getInstance() {
+        log.info("MetricsSingleton.getInstance()");
+
+        if (Objects.isNull(metricsSingleton)) {
+            metricsSingleton = new MetricsSingleton();
+        }
+
+        return metricsSingleton;
+    }
+}

quads-loader/src/main/java/fr/vcity/converg/QuadsLoaderApplication.java

@@ -1,9 +1,7 @@
 package fr.vcity.converg;
 
-import io.prometheus.metrics.core.metrics.Counter;
-import io.prometheus.metrics.instrumentation.jvm.JvmMetrics;
 import io.prometheus.metrics.exporter.httpserver.HTTPServer;
-import io.prometheus.metrics.model.snapshots.Unit;
+import io.prometheus.metrics.instrumentation.jvm.JvmMetrics;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@@ -12,7 +10,7 @@
 @SpringBootApplication
 public class QuadsLoaderApplication {
 
-    public static void main(String[] args) throws IOException, InterruptedException {
+    public static void main(String[] args) throws IOException {
         SpringApplication.run(QuadsLoaderApplication.class, args);
 
         JvmMetrics.builder().register();
@@ -21,19 +19,7 @@ public static void main(String[] args) throws IOException, InterruptedException
                 .port(9400)
                 .buildAndStart();
 
-        Counter counter =
-                Counter.builder()
-                        .name("uptime_seconds_total")
-                        .help("total number of seconds since this application was started")
-                        .unit(Unit.SECONDS)
-                        .register();
-
         System.out.println(
                 "HTTPServer listening on port:" + server.getPort() + "/metrics");
-
-        while (true) {
-            Thread.sleep(1000);
-            counter.inc();
-        }
     }
 }

quads-loader/src/main/java/fr/vcity/converg/services/QuadImportService.java

@@ -1,5 +1,6 @@
 package fr.vcity.converg.services;
 
+import fr.vcity.converg.MetricsSingleton;
 import fr.vcity.converg.dao.ResourceOrLiteral;
 import fr.vcity.converg.dao.Version;
 import fr.vcity.converg.repository.*;
@@ -73,35 +74,13 @@ public record QuadValueType(TripleValueType tripleValueType, String namedGraph,
     Set<String> namedGraphs = new HashSet<>();
     List<TripleValueType> tripleValueTypes = new ArrayList<>();
 
-    Counter counterVersionTotal =
-            Counter.builder()
-                    .name("version_count_total")
-                    .help("number of version that have been imported in the database")
-                    .register();
-
-    Summary summaryVersionBatchingDuration =
-            Summary.builder()
-                    .name("file_at_version_batching_duration_seconds")
-                    .help("duration of the file batching in seconds at a certain version")
-                    .unit(Unit.SECONDS)
-                    .labelNames("filename", "version")
-                    .register();
-
-    Summary summaryVersionCatalogDuration =
-            Summary.builder()
-                    .name("file_at_version_catalog_duration_seconds")
-                    .help("duration of the file catalog in seconds at a certain version")
-                    .unit(Unit.SECONDS)
-                    .labelNames("filename", "version")
-                    .register();
-
-    Summary summaryVersionCondensingDuration =
-            Summary.builder()
-                    .name("file_at_version_condensing_duration_seconds")
-                    .help("duration of the file condensing in seconds at a certain version")
-                    .unit(Unit.SECONDS)
-                    .labelNames("filename", "version")
-                    .register();
+    Counter counterVersionTotal = MetricsSingleton.getInstance().counterVersionTotal;
+
+    Summary summaryVersionBatchingDuration = MetricsSingleton.getInstance().summaryVersionBatchingDuration;
+
+    Summary summaryVersionCatalogDuration = MetricsSingleton.getInstance().summaryVersionCatalogDuration;
+
+    Summary summaryVersionCondensingDuration = MetricsSingleton.getInstance().summaryVersionCondensingDuration;
 
     public QuadImportService(
             IFlatModelQuadRepository flatModelQuadRepository,