Add metric for requests per connection

6 files changed, 80 insertions, 4 deletions

diff --git a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectionMetricAggregator.java b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectionMetricAggregator.java
new file mode 100644
index 00000000000..a92cbf264a4
--- /dev/null
+++ b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectionMetricAggregator.java
@@ -0,0 +1,65 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.jdisc.http.server.jetty;
+
+import com.yahoo.jdisc.Metric;
+import com.yahoo.jdisc.http.ServerConfig;
+import org.eclipse.jetty.io.Connection;
+import org.eclipse.jetty.server.HttpChannel;
+import org.eclipse.jetty.server.Request;
+import org.eclipse.jetty.util.component.AbstractLifeCycle;
+
+import java.util.Collection;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static com.yahoo.jdisc.http.server.jetty.RequestUtils.getConnector;
+import static com.yahoo.jdisc.http.server.jetty.RequestUtils.isHttpServerConnection;
+
+/**
+ * @author bjorncs
+ */
+class ConnectionMetricAggregator extends AbstractLifeCycle implements Connection.Listener, HttpChannel.Listener{
+
+    private final SimpleConcurrentIdentityHashMap<Connection, ConnectionMetrics> connectionsMetrics = new SimpleConcurrentIdentityHashMap<>();
+
+    private final Metric metricAggregator;
+    private final Collection<String> monitoringHandlerPaths;
+
+    ConnectionMetricAggregator(ServerConfig serverConfig, Metric metricAggregator) {
+        this.monitoringHandlerPaths = serverConfig.metric().monitoringHandlerPaths();
+        this.metricAggregator = metricAggregator;
+    }
+
+    @Override public void onOpened(Connection connection) {}
+
+    @Override
+    public void onClosed(Connection connection) {
+        if (isHttpServerConnection(connection)) {
+            connectionsMetrics.remove(connection).ifPresent(metrics ->
+                    metricAggregator.set(MetricDefinitions.REQUESTS_PER_CONNECTION, metrics.requests.get(), metrics.metricContext));
+        }
+    }
+
+    @Override
+    public void onRequestBegin(Request request) {
+        if (monitoringHandlerPaths.stream()
+                .anyMatch(pathPrefix -> request.getRequestURI().startsWith(pathPrefix))){
+            return;
+        }
+        Connection connection = request.getHttpChannel().getConnection();
+        if (isHttpServerConnection(connection)) {
+            ConnectionMetrics metrics = this.connectionsMetrics.computeIfAbsent(
+                    connection,
+                    () -> new ConnectionMetrics(getConnector(request).getConnectorMetricContext()));
+            metrics.requests.incrementAndGet();
+        }
+    }
+
+    private static class ConnectionMetrics {
+        final AtomicLong requests = new AtomicLong();
+        final Metric.Context metricContext;
+
+        ConnectionMetrics(Metric.Context metricContext) {
+            this.metricContext = metricContext;
+        }
+    }
+}
diff --git a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectorFactory.java b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectorFactory.java
index b9b6bcf57f0..9d14771d242 100644
--- a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectorFactory.java
+++ b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/ConnectorFactory.java
@@ -66,9 +66,11 @@ public class ConnectorFactory {
         return connectorConfig;
     }
 
-    public ServerConnector createConnector(final Metric metric, final Server server, JettyConnectionLogger connectionLogger) {
+    public ServerConnector createConnector(final Metric metric, final Server server, JettyConnectionLogger connectionLogger,
+                                           ConnectionMetricAggregator connectionMetricAggregator) {
         ServerConnector connector = new JDiscServerConnector(
-                connectorConfig, metric, server, connectionLogger, createConnectionFactories(metric).toArray(ConnectionFactory[]::new));
+                connectorConfig, metric, server, connectionLogger, connectionMetricAggregator,
+                createConnectionFactories(metric).toArray(ConnectionFactory[]::new));
         connector.setPort(connectorConfig.listenPort());
         connector.setName(connectorConfig.name());
         connector.setAcceptQueueSize(connectorConfig.acceptQueueSize());
diff --git a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/JDiscServerConnector.java b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/JDiscServerConnector.java
index a355ca886c5..ae475ca4517 100644
--- a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/JDiscServerConnector.java
+++ b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/JDiscServerConnector.java
@@ -31,7 +31,8 @@ class JDiscServerConnector extends ServerConnector {
     private final String connectorName;
     private final int listenPort;
 
-    JDiscServerConnector(ConnectorConfig config, Metric metric, Server server, JettyConnectionLogger connectionLogger, ConnectionFactory... factories) {
+    JDiscServerConnector(ConnectorConfig config, Metric metric, Server server, JettyConnectionLogger connectionLogger,
+                         ConnectionMetricAggregator connectionMetricAggregator, ConnectionFactory... factories) {
         super(server, factories);
         this.config = config;
         this.tcpKeepAlive = config.tcpKeepAliveEnabled();
@@ -48,6 +49,7 @@ class JDiscServerConnector extends ServerConnector {
             new ConnectionThrottler(this, throttlingConfig).registerWithConnector();
         }
         addBean(connectionLogger);
+        addBean(connectionMetricAggregator);
     }
 
     @Override
diff --git a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/JettyHttpServer.java b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/JettyHttpServer.java
index cf9945cc65b..70f173b74e5 100644
--- a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/JettyHttpServer.java
+++ b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/JettyHttpServer.java
@@ -83,10 +83,11 @@ public class JettyHttpServer extends AbstractServerProvider {
         setupJmx(server, serverConfig);
         configureJettyThreadpool(server, serverConfig);
         JettyConnectionLogger connectionLogger = new JettyConnectionLogger(serverConfig.connectionLog(), connectionLog);
+        ConnectionMetricAggregator connectionMetricAggregator = new ConnectionMetricAggregator(serverConfig, metric);
 
         for (ConnectorFactory connectorFactory : connectorFactories.allComponents()) {
             ConnectorConfig connectorConfig = connectorFactory.getConnectorConfig();
-            server.addConnector(connectorFactory.createConnector(metric, server, connectionLogger));
+            server.addConnector(connectorFactory.createConnector(metric, server, connectionLogger, connectionMetricAggregator));
             listenedPorts.add(connectorConfig.listenPort());
         }
 
diff --git a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/MetricDefinitions.java b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/MetricDefinitions.java
index b0b7ae14739..172e6483de2 100644
--- a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/MetricDefinitions.java
+++ b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/MetricDefinitions.java
@@ -24,6 +24,7 @@ class MetricDefinitions {
     static final String CONNECTION_DURATION_MEAN = "serverConnectionDurationMean";
     static final String CONNECTION_DURATION_STD_DEV = "serverConnectionDurationStdDev";
     static final String NUM_PREMATURELY_CLOSED_CONNECTIONS = "jdisc.http.request.prematurely_closed";
+    static final String REQUESTS_PER_CONNECTION = "jdisc.http.request.requests_per_connection";
 
     static final String NUM_BYTES_RECEIVED = "serverBytesReceived";
     static final String NUM_BYTES_SENT     = "serverBytesSent";
diff --git a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/RequestUtils.java b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/RequestUtils.java
index 5fca7a8d778..b248f55a3df 100644
--- a/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/RequestUtils.java
+++ b/container-core/src/main/java/com/yahoo/jdisc/http/server/jetty/RequestUtils.java
@@ -1,6 +1,7 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.jdisc.http.server.jetty;
 
+import org.eclipse.jetty.http2.server.HTTP2ServerConnection;
 import org.eclipse.jetty.io.Connection;
 import org.eclipse.jetty.server.HttpConnection;
 import org.eclipse.jetty.server.Request;
@@ -28,6 +29,10 @@ public class RequestUtils {
         return (JDiscServerConnector) request.getHttpChannel().getConnector();
     }
 
+    static boolean isHttpServerConnection(Connection connection) {
+        return connection instanceof HttpConnection || connection instanceof HTTP2ServerConnection;
+    }
+
     /**
      * Note: {@link HttpServletRequest#getLocalPort()} may return the local port of the load balancer / reverse proxy if proxy-protocol is enabled.
      * @return the actual local port of the underlying Jetty connector