Add JMXFetch telemetry around bean/attribute matching

src/main/java/org/datadog/jmxfetch/Instance.java

@@ -509,13 +509,18 @@ public List<Metric> getMetrics() throws IOException {
                 }
             }
         }
-        instanceTelemetryBean.setBeansFetched(beans.size());
-        instanceTelemetryBean.setTopLevelAttributeCount(matchingAttributes.size());
-        instanceTelemetryBean.setMetricCount(metrics.size());
-        log.debug("Updated jmx bean for instance: " + this.getCheckName()
-                + " With beans fetched = " + instanceTelemetryBean.getBeansFetched()
-                + " top attributes = " + instanceTelemetryBean.getTopLevelAttributeCount()
-                + " metrics = " + instanceTelemetryBean.getMetricCount());
+        if (instanceTelemetryBean != null) {
+            instanceTelemetryBean.setBeansFetched(beans.size());
+            instanceTelemetryBean.setTopLevelAttributeCount(matchingAttributes.size());
+            instanceTelemetryBean.setMetricCount(metrics.size());
+            log.debug("Updated jmx bean for instance: " + this.getCheckName()
+                    + " With beans fetched = " + instanceTelemetryBean.getBeansFetched()
+                    + " top attributes = " + instanceTelemetryBean.getTopLevelAttributeCount()
+                    + " metrics = " + instanceTelemetryBean.getMetricCount()
+                    + " wildcard domain query count = " 
+                    + instanceTelemetryBean.getWildcardDomainQueryCount() 
+                    + " bean match ratio = " + instanceTelemetryBean.getBeanMatchRatio());
+        }
         return metrics;
     }
 
@@ -547,11 +552,14 @@ private void getMatchingAttributes() throws IOException {
         this.failingAttributes.clear();
         int metricsCount = 0;
 
+        int beansWithAttributeMatch = 0;
+
         if (!action.equals(AppConfig.ACTION_COLLECT)) {
             reporter.displayInstanceName(this);
         }
 
         for (ObjectName beanName : this.beans) {
+            boolean attributeMatched = false;
             if (limitReached) {
                 log.debug("Limit reached");
                 if (action.equals(AppConfig.ACTION_COLLECT)) {
@@ -702,7 +710,17 @@ private void getMatchingAttributes() throws IOException {
                             || action.equals(AppConfig.ACTION_LIST_NOT_MATCHING))) {
                     reporter.displayNonMatchingAttributeName(jmxAttribute);
                 }
+                if (jmxAttribute.getMatchingConf() != null) {
+                    attributeMatched = true; 
+                }
             }
+            if (attributeMatched) {
+                beansWithAttributeMatch += 1;
+            }
+        }
+        if (instanceTelemetryBean != null) {
+            instanceTelemetryBean.setBeanMatchRatio((double) 
+                                  beansWithAttributeMatch / beans.size());
         }
         log.info("Found {} matching attributes", matchingAttributes.size());
     }
@@ -733,14 +751,21 @@ private void refreshBeansList() throws IOException {
                     ObjectName name = new ObjectName(scope);
                     this.beans.addAll(connection.queryNames(name));
                 }
-            } catch (Exception e) {
+            } catch (MalformedObjectNameException e) {
+                log.error("Unable to create ObjectName", e);
+            } catch (IOException e) {
                 log.error(
-                        "Unable to compute a common bean scope, querying all beans as a fallback",
-                        e);
+                        "Unable to query mbean server", e);
             }
         }
 
-        this.beans = (this.beans.isEmpty()) ? connection.queryNames(null) : this.beans;
+        if (this.beans.isEmpty()) {
+            this.beans = connection.queryNames(null);
+            if (instanceTelemetryBean != null) {
+                int wildcardQueryCount = instanceTelemetryBean.getWildcardDomainQueryCount();
+                instanceTelemetryBean.setWildcardDomainQueryCount(wildcardQueryCount + 1);
+            }
+        }
         this.lastRefreshTime = System.currentTimeMillis();
     }
 

src/main/java/org/datadog/jmxfetch/Status.java

@@ -127,6 +127,10 @@ private void addStats(
             instStats.put("instance_attribute_count", 
                           instanceTelemetryBean.getTopLevelAttributeCount());
             instStats.put("instance_metric_count", instanceTelemetryBean.getMetricCount());
+            instStats.put("instance_wildcard_domain_query_count", 
+                          instanceTelemetryBean.getWildcardDomainQueryCount());
+            instStats.put("instance_bean_match_ratio",
+                          instanceTelemetryBean.getBeanMatchRatio());
         }
         instStats.put("message", message);
         instStats.put("status", status);

src/main/java/org/datadog/jmxfetch/util/InstanceTelemetry.java

@@ -7,12 +7,16 @@ public class InstanceTelemetry implements InstanceTelemetryMBean {
     private int beansFetched;
     private int topLevelAttributeCount;
     private int metricCount;
+    private int wildcardDomainQueryCount;
+    private double beanMatchRatio;
 
     /** Jmxfetch telemetry bean constructor. */
     public InstanceTelemetry() {
         beansFetched = 0;
         topLevelAttributeCount = 0;
         metricCount = 0;
+        wildcardDomainQueryCount = 0;
+        beanMatchRatio = 0.0;
     }
 
     public int getBeansFetched() {
@@ -27,6 +31,13 @@ public int getMetricCount() {
         return metricCount;
     }
 
+    public int getWildcardDomainQueryCount() {
+        return wildcardDomainQueryCount;
+    }
+
+    public double getBeanMatchRatio() {
+        return beanMatchRatio;
+    }
 
     public void setBeansFetched(int count) {
         beansFetched = count;
@@ -40,5 +51,12 @@ public void setMetricCount(int count) {
         metricCount = count;
     }
 
+    public void setWildcardDomainQueryCount(int count) {
+        wildcardDomainQueryCount = count;
+    }
+
+    public void setBeanMatchRatio(double ratio) {
+        beanMatchRatio = ratio;
+    }
 
 }

src/main/java/org/datadog/jmxfetch/util/InstanceTelemetryMBean.java

@@ -8,4 +8,8 @@ public interface InstanceTelemetryMBean {
 
     int getMetricCount();
 
+    int getWildcardDomainQueryCount();
+
+    double getBeanMatchRatio();
+
 }

src/test/java/org/datadog/jmxfetch/StatusTest.java

@@ -33,10 +33,14 @@ public void TestStatus() throws IOException {
         int fakeBeansFetched = 11;
         int fakeMetricCount = 29;
         int fakeAttributeCount = 55;
+        int fakeWildcardDomainQueryCount = 9;
+        double fakeBeanMatchRatio = .4;
 
         instance.setBeansFetched(fakeBeansFetched);
         instance.setMetricCount(fakeMetricCount);
         instance.setTopLevelAttributeCount(fakeAttributeCount);
+        instance.setWildcardDomainQueryCount(fakeWildcardDomainQueryCount);
+        instance.setBeanMatchRatio(fakeBeanMatchRatio);
 
         status.addInstanceStats("fake_check", "fake_instance", 10, 3, "fake_message", Status.STATUS_OK, instance);
         status.flush();
@@ -55,6 +59,8 @@ public void TestStatus() throws IOException {
         assertEquals(fakeBeansFetched, stats.get("instance_bean_count"));
         assertEquals(fakeAttributeCount, stats.get("instance_attribute_count"));
         assertEquals(fakeMetricCount, stats.get("instance_metric_count"));
+        assertEquals(fakeWildcardDomainQueryCount, stats.get("instance_wildcard_domain_query_count"));
+        assertEquals(fakeBeanMatchRatio, stats.get("instance_bean_match_ratio"));
         assertEquals("fake_message", stats.get("message"));
         assertEquals(Status.STATUS_OK, stats.get("status"));
     }