Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.solr.util.stats; import org.apache.http.conn.scheme.SchemeRegistry; import org.apache.http.impl.conn.PoolingClientConnectionManager; import org.apache.solr.metrics.SolrMetricManager; import org.apache.solr.metrics.SolrMetricProducer; /** * Sub-class of PoolingHttpClientConnectionManager which tracks metrics interesting to Solr. * Inspired by dropwizard metrics-httpclient library implementation. */ public class InstrumentedPoolingClientConnectionManager extends PoolingClientConnectionManager implements SolrMetricProducer { public InstrumentedPoolingClientConnectionManager(SchemeRegistry schreg) { super(schreg); } @Override public void initializeMetrics(SolrMetricManager manager, String registry, String scope) { // these acquire a lock on the connection pool; remove if contention sucks manager.registerGauge(registry, () -> getTotalStats().getAvailable(), true, SolrMetricManager.mkName("availableConnections", scope)); manager.registerGauge(registry, () -> getTotalStats().getLeased(), true, SolrMetricManager.mkName("leasedConnections", scope)); manager.registerGauge(registry, () -> getTotalStats().getMax(), true, SolrMetricManager.mkName("maxConnections", scope)); manager.registerGauge(registry, () -> getTotalStats().getPending(), true, SolrMetricManager.mkName("pendingConnections", scope)); } }