package org.apache.cassandra.utils; /* * * 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. * */ import java.io.IOException; import java.io.RandomAccessFile; import java.lang.management.ManagementFactory; import java.net.InetAddress; import java.util.StringTokenizer; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import org.apache.cassandra.concurrent.DebuggableScheduledThreadPoolExecutor; import org.apache.cassandra.gms.ApplicationState; import org.apache.cassandra.gms.EndpointState; import org.apache.cassandra.gms.Gossiper; import org.apache.cassandra.gms.VersionedValue; import org.apache.cassandra.service.StorageService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.common.util.concurrent.AtomicDouble; public class BackgroundActivityMonitor { private static final Logger logger = LoggerFactory.getLogger(BackgroundActivityMonitor.class); public static final int USER_INDEX = 0; public static final int NICE_INDEX = 1; public static final int SYS_INDEX = 2; public static final int IDLE_INDEX = 3; public static final int IOWAIT_INDEX = 4; public static final int IRQ_INDEX = 5; public static final int SOFTIRQ_INDEX = 6; private static final String OPERATING_SYSTEM = System.getProperty("os.name").toLowerCase(); private static final int NUM_CPUS = Runtime.getRuntime().availableProcessors(); private static final String PROC_STAT_PATH = "/proc/stat"; private final AtomicDouble compaction_severity = new AtomicDouble(); private final ScheduledExecutorService reportThread = new DebuggableScheduledThreadPoolExecutor("Background_Reporter"); private RandomAccessFile statsFile; private long[] lastReading; public BackgroundActivityMonitor() { try { statsFile = new RandomAccessFile(PROC_STAT_PATH, "r"); lastReading = readAndCompute(); } catch (IOException ex) { if (isUnix()) logger.warn("Couldn't open /proc/stats"); statsFile = null; } reportThread.scheduleAtFixedRate(new BackgroundActivityReporter(), 1, 1, TimeUnit.SECONDS); } public static boolean isUnix() { return OPERATING_SYSTEM.contains("nix") || OPERATING_SYSTEM.contains("nux") || OPERATING_SYSTEM.contains("aix"); } private long[] readAndCompute() throws IOException { statsFile.seek(0); StringTokenizer tokenizer = new StringTokenizer(statsFile.readLine()); String name = tokenizer.nextToken(); assert name.equalsIgnoreCase("cpu"); long[] returned = new long[tokenizer.countTokens()]; for (int i = 0; i < tokenizer.countTokens(); i++) returned[i] = Long.parseLong(tokenizer.nextToken()); return returned; } private float compareAtIndex(long[] reading1, long[] reading2, int index) { long total1 = 0, total2 = 0; for (int i = 0; i <= SOFTIRQ_INDEX; i++) { total1 += reading1[i]; total2 += reading2[i]; } float totalDiff = total2 - total1; long intrested1 = reading1[index], intrested2 = reading2[index]; float diff = intrested2 - intrested1; if (diff == 0) return 0f; return (diff / totalDiff) * 100; // yes it is hard coded to 100 [update // unit?] } public void incrCompactionSeverity(double sev) { compaction_severity.addAndGet(sev); } public double getIOWait() throws IOException { if (statsFile == null) return -1d; long[] newComp = readAndCompute(); double value = compareAtIndex(lastReading, newComp, IOWAIT_INDEX); lastReading = newComp; return value; } public double getNormalizedLoadAvg() { double avg = ManagementFactory.getOperatingSystemMXBean().getSystemLoadAverage(); return avg / NUM_CPUS; } public double getSeverity(InetAddress endpoint) { VersionedValue event; EndpointState state = Gossiper.instance.getEndpointStateForEndpoint(endpoint); if (state != null && (event = state.getApplicationState(ApplicationState.SEVERITY)) != null) return Double.parseDouble(event.value); return 0.0; } public class BackgroundActivityReporter implements Runnable { public void run() { double report = -1; try { report = getIOWait(); } catch (IOException e) { // ignore; if (isUnix()) logger.warn("Couldn't read /proc/stats"); } if (report == -1d) report = compaction_severity.get(); if (!Gossiper.instance.isEnabled()) return; VersionedValue updated = StorageService.instance.valueFactory.severity(report); Gossiper.instance.addLocalApplicationState(ApplicationState.SEVERITY, updated); } } }