jetty threads

Author: SylvainJuge

jmx-scraper/src/integrationTest/java/io/opentelemetry/contrib/jmxscraper/target_systems/JettyIntegrationTest.java

@@ -74,6 +74,14 @@ protected void verifyMetrics() {
                 "s",
                 attrs -> attrs.containsKey("resource")),
         metric ->
-            assertSum(metric, "jetty.select.count", "The number of select calls.", "{operations}"));
+            assertSum(metric, "jetty.select.count", "The number of select calls.", "{operations}"),
+        metric ->
+            assertGaugeWithAttributes(
+                metric,
+                "jetty.thread.count",
+                "The current number of threads.",
+                "{threads}",
+                attrs -> attrs.containsEntry("state", "busy"),
+                attrs -> attrs.containsEntry("state", "idle")));
   }
 }

jmx-scraper/src/main/resources/jetty.yaml

@@ -32,3 +32,18 @@ rules:
         type: gauge
         unit: s
         desc: The maximum amount of time a session has been active.
+
+  - bean: org.eclipse.jetty.util.thread:type=queuedthreadpool,id=*
+    prefix: jetty.thread.
+    unit: "{threads}"
+    mapping:
+      busyThreads:
+        metric: count
+        desc: The current number of threads.
+        metricAttribute:
+          state: const(busy)
+      idleThreads:
+        metric: count
+        desc: The current number of threads.
+        metricAttribute:
+          state: const(idle)