Merge pull request #312 from dmuino/tomcat

Add servo-tomcat subproject: generate metrics related to tomcat

servo-tomcat/build.gradle

@@ -0,0 +1,3 @@
+dependencies {
+  compile project(':servo-core')
+}

servo-tomcat/src/main/java/com/netflix/servo/publish/tomcat/TomcatPoller.java

@@ -0,0 +1,190 @@
+/*
+ * Copyright 2015 Netflix, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.netflix.servo.publish.tomcat;
+
+import com.netflix.servo.Metric;
+import com.netflix.servo.annotations.DataSourceType;
+import com.netflix.servo.monitor.MonitorConfig;
+import com.netflix.servo.publish.BaseMetricPoller;
+import com.netflix.servo.tag.BasicTagList;
+import com.netflix.servo.tag.Tag;
+import com.netflix.servo.tag.TagList;
+import com.netflix.servo.tag.Tags;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.management.Attribute;
+import javax.management.AttributeList;
+import javax.management.JMException;
+import javax.management.MBeanServer;
+import javax.management.ObjectName;
+import java.lang.management.ManagementFactory;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * Fetch Tomcat metrics from JMX.
+ */
+public class TomcatPoller extends BaseMetricPoller {
+    private static final List<Metric> EMPTY_LIST = Collections.emptyList();
+    private static final Logger LOGGER = LoggerFactory.getLogger(TomcatPoller.class);
+
+
+    private static String normalizeName(String name) {
+        return "tomcat." + (name.equals("activeCount") ? "currentThreadsBusy" : name);
+    }
+
+    private static Metric toMetric(long t, ObjectName name, Attribute attribute, Tag dsType) {
+        Tag id = Tags.newTag("id", name.getKeyProperty("name"));
+        Tag clazz = Tags.newTag("class", name.getKeyProperty("type"));
+        TagList list = BasicTagList.of(id, clazz, dsType);
+        return new Metric(normalizeName(attribute.getName()), list, t, attribute.getValue());
+    }
+
+    private static Metric toGauge(long t, ObjectName name, Attribute attribute) {
+        return toMetric(t, name, attribute, DataSourceType.GAUGE);
+    }
+
+    private static Metric toCounter(long t, ObjectName name, Attribute attribute) {
+        return toMetric(t, name, attribute, DataSourceType.COUNTER);
+    }
+
+    private static final String[] THREAD_POOL_ATTRS = new String[]{
+            "maxThreads",
+            "currentThreadCount",
+            "currentThreadsBusy",
+            "backlog"
+    };
+
+    private static final String[] GLOBAL_REQ_ATTRS = new String[]{
+            "requestCount",
+            "errorCount",
+            "bytesSent",
+            "processingTime",
+            "maxTime"
+    };
+
+    private static final String[] EXECUTOR_ATTRS = new String[]{
+            "maxThreads",
+            "completedTaskCount",
+            "queueSize",
+            "poolSize",
+            "activeCount"
+    };
+
+    private static void addMetric(List<Metric> metrics, Metric metric) {
+        if (metric.getNumberValue().doubleValue() >= 0.0) {
+            final MonitorConfig c = metric.getConfig();
+            if (LOGGER.isDebugEnabled()) {
+                LOGGER.debug("Adding " + c.getName() + " " + c.getTags() + " "
+                        + metric.getNumberValue());
+            }
+            metrics.add(metric);
+        } else {
+            LOGGER.debug("Ignoring {}", metric);
+        }
+    }
+
+    private static void fetchRequestProcessorMetrics(long now, MBeanServer mbs,
+                                                     List<Metric> metrics) throws JMException {
+        final ObjectName globalName = new ObjectName("Catalina:type=GlobalRequestProcessor,*");
+        final Set<ObjectName> names = mbs.queryNames(globalName, null);
+        if (names == null) {
+            return;
+        }
+
+        for (ObjectName name : names) {
+            AttributeList list = mbs.getAttributes(name, GLOBAL_REQ_ATTRS);
+            for (Attribute a : list.asList()) {
+                // the only gauge here is maxTime
+                addMetric(metrics, a.getName().equals("maxTime")
+                        ? toGauge(now, name, a)
+                        : toCounter(now, name, a));
+            }
+        }
+    }
+
+    private static void fetchThreadPoolMetrics(long now, MBeanServer mbs, List<Metric> metrics)
+            throws JMException {
+        final ObjectName threadPoolName = new ObjectName("Catalina:type=ThreadPool,*");
+        final Set<ObjectName> names = mbs.queryNames(threadPoolName, null);
+        if (names == null) {
+            return;
+        }
+
+        for (ObjectName name : names) {
+            AttributeList list = mbs.getAttributes(name, THREAD_POOL_ATTRS);
+            // determine whether the shared threadPool is used
+            boolean isUsed = true;
+            for (Attribute a : list.asList()) {
+                if (a.getName().equals("maxThreads")) {
+                    Number v = (Number) a.getValue();
+                    isUsed = v.doubleValue() >= 0.0;
+                    break;
+                }
+            }
+
+            if (isUsed) {
+                // only add the attributes if the metric is used.
+                for (Attribute a : list.asList()) {
+                    addMetric(metrics, toGauge(now, name, a));
+                }
+            }
+        }
+    }
+
+    private static void fetchExecutorMetrics(long now, MBeanServer mbs, List<Metric> metrics)
+            throws JMException {
+        final ObjectName executorName = new ObjectName("Catalina:type=Executor,*");
+        final Set<ObjectName> names = mbs.queryNames(executorName, null);
+        if (names == null) {
+            return;
+        }
+
+        for (ObjectName name : names) {
+            AttributeList list = mbs.getAttributes(name, EXECUTOR_ATTRS);
+            for (Attribute a : list.asList()) {
+                addMetric(metrics, a.getName().equals("completedTaskCount")
+                        ? toCounter(now, name, a)
+                        : toGauge(now, name, a));
+            }
+        }
+    }
+
+    List<Metric> pollImpl(long timestamp) {
+        try {
+            MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
+            List<Metric> metrics = new ArrayList<Metric>();
+            fetchThreadPoolMetrics(timestamp, mbs, metrics);
+            fetchRequestProcessorMetrics(timestamp, mbs, metrics);
+            fetchExecutorMetrics(timestamp, mbs, metrics);
+            return metrics;
+        } catch (JMException e) {
+            logger.error("Could not get Tomcat JMX metrics", e);
+            return EMPTY_LIST;
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public List<Metric> pollImpl(boolean reset) {
+        return pollImpl(System.currentTimeMillis());
+    }
+}

settings.gradle

@@ -14,4 +14,5 @@
  *     limitations under the License.
  */
 
-include 'servo-internal', 'servo-core','servo-apache','servo-aws','servo-graphite','servo-example'
+include 'servo-internal', 'servo-core','servo-apache','servo-aws','servo-graphite','servo-example', 
+    'servo-tomcat'