Code review changes

Author: robsunday

instrumentation/jmx-metrics/library/src/main/resources/jmx/rules/tomcat.yaml

@@ -58,7 +58,12 @@ rules:
         metric: session.active.count
         type: updowncounter
         unit: "{session}"
-        desc: The number of active sessions.
+        desc: The number of currently active sessions.
+      maxActiveSessions:
+        metric: session.active.limit
+        type: updowncounter
+        unit: "{session}"
+        desc: Maximum number of active sessions.
 
   - beans:
     - Catalina:type=ThreadPool,name=*
@@ -72,6 +77,9 @@ rules:
       currentThreadCount:
         metric: count
         desc: Total thread count of the thread pool.
+      maxThreads:
+        metric: limit
+        desc: Maximum thread count of the thread pool.
       currentThreadsBusy:
         metric: busy.count
         desc: Number of busy threads in the thread pool.

instrumentation/jmx-metrics/library/src/test/java/io/opentelemetry/instrumentation/jmx/rules/TomcatIntegrationTest.java

@@ -48,7 +48,7 @@ void testCollectedMetrics(String dockerImageName, String sampleWebApplicationUrl
 
     startTarget(target);
 
-    // Deploy example web application to the tomcat to enable reporting tomcat.active_session.count
+    // Deploy example web application to the tomcat to enable reporting tomcat.session.active.count
     // metric
     target.execInContainer("rm", "-fr", "/usr/local/tomcat/webapps/ROOT");
     target.execInContainer(
@@ -61,7 +61,7 @@ private static MetricsVerifier createMetricsVerifier() {
     AttributeMatcher requestProcessorNameAttribute =
         attribute("tomcat.request_processor.name", "\"http-nio-8080\"");
     AttributeMatcher threadPoolNameAttribute =
-        attribute("tomcat.thread_pool.name", "\"http-nio-8080\"");
+        attribute("tomcat.thread.pool.name", "\"http-nio-8080\"");
 
     return MetricsVerifier.create()
         .add(
@@ -111,10 +111,18 @@ private static MetricsVerifier createMetricsVerifier() {
                             attribute("network.io.direction", "transmit"),
                             requestProcessorNameAttribute)))
         .add(
-            "tomcat.active_session.count",
+            "tomcat.session.active.count",
             metric ->
                 metric
-                    .hasDescription("The number of active sessions.")
+                    .hasDescription("The number of currently active sessions.")
+                    .hasUnit("{session}")
+                    .isUpDownCounter()
+                    .hasDataPointsWithOneAttribute(attributeWithAnyValue("tomcat.context")))
+        .add(
+            "tomcat.session.active.limit",
+            metric ->
+                metric
+                    .hasDescription("Maximum number of active sessions.")
                     .hasUnit("{session}")
                     .isUpDownCounter()
                     .hasDataPointsWithOneAttribute(attributeWithAnyValue("tomcat.context")))
@@ -126,6 +134,14 @@ private static MetricsVerifier createMetricsVerifier() {
                     .hasUnit("{thread}")
                     .isUpDownCounter()
                     .hasDataPointsWithOneAttribute(threadPoolNameAttribute))
+        .add(
+            "tomcat.thread.limit",
+            metric ->
+                metric
+                    .hasDescription("Maximum thread count of the thread pool.")
+                    .hasUnit("{thread}")
+                    .isUpDownCounter()
+                    .hasDataPointsWithOneAttribute(threadPoolNameAttribute))
         .add(
             "tomcat.thread.busy.count",
             metric ->