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.zookeeper.server; import java.util.concurrent.atomic.AtomicLong; import org.apache.zookeeper.common.Time; import org.apache.zookeeper.server.metric.AvgMinMaxCounter; import org.apache.zookeeper.server.quorum.BufferStats; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Basic Server Statistics */ public class ServerStats { private static final Logger LOG = LoggerFactory.getLogger(ServerStats.class); private final AtomicLong packetsSent = new AtomicLong(); private final AtomicLong packetsReceived = new AtomicLong(); private final AvgMinMaxCounter requestLatency = new AvgMinMaxCounter("request_latency"); private final AtomicLong fsyncThresholdExceedCount = new AtomicLong(0); private final BufferStats clientResponseStats = new BufferStats(); private final Provider provider; private final long startTime = Time.currentElapsedTime(); public interface Provider { long getOutstandingRequests(); long getLastProcessedZxid(); String getState(); int getNumAliveConnections(); long getDataDirSize(); long getLogDirSize(); } public ServerStats(Provider provider) { this.provider = provider; } // getters public long getMinLatency() { return requestLatency.getMin(); } public double getAvgLatency() { return requestLatency.getAvg(); } public long getMaxLatency() { return requestLatency.getMax(); } public long getOutstandingRequests() { return provider.getOutstandingRequests(); } public long getLastProcessedZxid() { return provider.getLastProcessedZxid(); } public long getDataDirSize() { return provider.getDataDirSize(); } public long getLogDirSize() { return provider.getLogDirSize(); } public long getPacketsReceived() { return packetsReceived.get(); } public long getPacketsSent() { return packetsSent.get(); } public String getServerState() { return provider.getState(); } /** The number of client connections alive to this server */ public int getNumAliveClientConnections() { return provider.getNumAliveConnections(); } public long getUptime() { return Time.currentElapsedTime() - startTime; } public boolean isProviderNull() { return provider == null; } @Override public String toString() { StringBuilder sb = new StringBuilder(); sb.append("Latency min/avg/max: " + getMinLatency() + "/" + getAvgLatency() + "/" + getMaxLatency() + "\n"); sb.append("Received: " + getPacketsReceived() + "\n"); sb.append("Sent: " + getPacketsSent() + "\n"); sb.append("Connections: " + getNumAliveClientConnections() + "\n"); if (provider != null) { sb.append("Outstanding: " + getOutstandingRequests() + "\n"); sb.append("Zxid: 0x" + Long.toHexString(getLastProcessedZxid()) + "\n"); } sb.append("Mode: " + getServerState() + "\n"); return sb.toString(); } /** * Update request statistic. This should only be called from a request * that originated from that machine. */ public void updateLatency(Request request, long currentTime) { long latency = currentTime - request.createTime; if (latency < 0) { return; } requestLatency.addDataPoint(latency); if (request.getHdr() != null) { // Only quorum request should have header ServerMetrics.getMetrics().UPDATE_LATENCY.add(latency); } else { // All read request should goes here ServerMetrics.getMetrics().READ_LATENCY.add(latency); } } public void resetLatency() { requestLatency.reset(); } public void resetMaxLatency() { requestLatency.resetMax(); } public void incrementPacketsReceived() { packetsReceived.incrementAndGet(); } public void incrementPacketsSent() { packetsSent.incrementAndGet(); } public void resetRequestCounters() { packetsReceived.set(0); packetsSent.set(0); } public long getFsyncThresholdExceedCount() { return fsyncThresholdExceedCount.get(); } public void incrementFsyncThresholdExceedCount() { fsyncThresholdExceedCount.incrementAndGet(); } public void resetFsyncThresholdExceedCount() { fsyncThresholdExceedCount.set(0); } public void reset() { resetLatency(); resetRequestCounters(); clientResponseStats.reset(); ServerMetrics.getMetrics().resetAll(); } public void updateClientResponseSize(int size) { clientResponseStats.setLastBufferSize(size); } public BufferStats getClientResponseStats() { return clientResponseStats; } }