ZOOKEEPER-3037 - Add unit test and various improvements

zookeeper-server/src/main/java/org/apache/zookeeper/server/ZooKeeperServer.java

@@ -224,14 +224,16 @@ public ZooKeeperServer(FileTxnSnapLog txnLogFactory, int tickTime,
 
     /**
      * Adds JvmPauseMonitor and calls
-     * {@link #ZooKeeperServer(FileTxnSnapLog, int, int, int, ZKDatabase)}
+     * {@link #ZooKeeperServer(FileTxnSnapLog, int, int, int, int, ZKDatabase)}
      *
      */
     public ZooKeeperServer(JvmPauseMonitor jvmPauseMonitor, FileTxnSnapLog txnLogFactory, int tickTime,
-                           int minSessionTimeout, int maxSessionTimeout, ZKDatabase zkDb) {
-        this(txnLogFactory, tickTime, minSessionTimeout, maxSessionTimeout, zkDb);
+                           int minSessionTimeout, int maxSessionTimeout, int clientPortListenBacklog, ZKDatabase zkDb) {
+        this(txnLogFactory, tickTime, minSessionTimeout, maxSessionTimeout, clientPortListenBacklog, zkDb);
         this.jvmPauseMonitor = jvmPauseMonitor;
-        LOG.info("Added JvmPauseMonitor to server");
+        if(jvmPauseMonitor != null) {
+            LOG.info("Added JvmPauseMonitor to server");
+        }
     }
 
     /**

zookeeper-server/src/main/java/org/apache/zookeeper/server/util/JvmPauseMonitor.java

@@ -46,17 +46,17 @@ public class JvmPauseMonitor {
     public static final String JVM_PAUSE_MONITOR_FEATURE_SWITCH_KEY = "jvm.pause.monitor";
 
     /** The target sleep time */
-    private long sleepTimeMs = SLEEP_TIME_MS_DEFAULT;
+    protected long sleepTimeMs;
     public static final String SLEEP_TIME_MS_KEY = "jvm.pause.sleep.time.ms";
     public static final long SLEEP_TIME_MS_DEFAULT = 500;
 
     /** log WARN if we detect a pause longer than this threshold */
-    private long warnThresholdMs = WARN_THRESHOLD_DEFAULT;
+    protected long warnThresholdMs;
     public static final String WARN_THRESHOLD_KEY = "jvm.pause.warn-threshold.ms";
     public static final long WARN_THRESHOLD_DEFAULT = 10000;
 
     /** log INFO if we detect a pause longer than this threshold */
-    private long infoThresholdMs = INFO_THRESHOLD_DEFAULT;
+    protected long infoThresholdMs;
     public static final String INFO_THRESHOLD_KEY = "jvm.pause.info-threshold.ms";
     public static final long INFO_THRESHOLD_DEFAULT = 1000;
 
@@ -128,10 +128,11 @@ private String formatMessage(long extraSleepTime,
             }
         }
 
-        String ret = "Detected pause in JVM or host machine (eg GC): " +
-                "pause of approximately " + extraSleepTime + "ms\n";
+        String ret = "Detected pause in JVM or host machine (eg GC): pause of approximately " + extraSleepTime
+                + "ms, total pause: info level: " + numGcInfoThresholdExceeded
+                + ", warn level: " + numGcWarnThresholdExceeded + "\n";
         if (gcDiffs.isEmpty()) {
-            ret += "No GCs detected";
+            ret += ("No GCs detected");
         } else {
             ret += String.join("\n", gcDiffs);
         }

zookeeper-server/src/test/java/org/apache/zookeeper/server/util/JvmPauseMonitorTest.java

@@ -0,0 +1,135 @@
+/**
+ * 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.util;
+
+import org.apache.zookeeper.server.ServerConfig;
+import org.apache.zookeeper.server.quorum.QuorumPeerConfig;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Properties;
+
+public class JvmPauseMonitorTest {
+
+    @Test
+    public void testJvmPauseMonitorInit() {
+        final Long sleepTime = 444L;
+        final Long warnTH = 5555L;
+        final Long infoTH = 555L;
+
+        ServerConfig serverConfig = new ServerConfig();
+        QuorumPeerConfig quorumPeerConfig = new QuorumPeerConfig();
+
+        Assert.assertEquals(false, serverConfig.isJvmPauseMonitorToRun());
+        Assert.assertEquals(false, quorumPeerConfig.isJvmPauseMonitorToRun());
+
+        Properties zkProp = new Properties();
+        zkProp.setProperty("dataDir", new File("myDataDir").getAbsolutePath());
+        zkProp.setProperty("jvm.pause.monitor", "true");
+        zkProp.setProperty("jvm.pause.sleep.time.ms", sleepTime.toString());
+        zkProp.setProperty("jvm.pause.warn-threshold.ms", warnTH.toString());
+        zkProp.setProperty("jvm.pause.info-threshold.ms", infoTH.toString());
+        try {
+            quorumPeerConfig.parseProperties(zkProp);
+        } catch (IOException | QuorumPeerConfig.ConfigException e) {
+            Assert.fail("Exception while reading config for JvmPauseMonitor");
+        }
+        serverConfig.readFrom(quorumPeerConfig);
+
+        Assert.assertEquals(true, serverConfig.isJvmPauseMonitorToRun());
+        Assert.assertEquals(true, quorumPeerConfig.isJvmPauseMonitorToRun());
+
+        JvmPauseMonitor pauseMonitor = new JvmPauseMonitor(serverConfig);
+        Assert.assertFalse(pauseMonitor.isStarted());
+        pauseMonitor.serviceStart();
+        Assert.assertTrue(pauseMonitor.isStarted());
+
+        Assert.assertEquals(sleepTime, Long.valueOf(pauseMonitor.sleepTimeMs));
+        Assert.assertEquals(warnTH, Long.valueOf(pauseMonitor.warnThresholdMs));
+        Assert.assertEquals(infoTH, Long.valueOf(pauseMonitor.infoThresholdMs));
+    }
+
+    @Test
+    public void testJvmPauseMonitorExceedInfoThreshold() throws InterruptedException {
+        final Long sleepTime = 100L;
+        final Long infoTH = -1L;
+
+        ServerConfig serverConfig = new ServerConfig();
+        QuorumPeerConfig quorumPeerConfig = new QuorumPeerConfig();
+
+        Properties zkProp = new Properties();
+        zkProp.setProperty("dataDir", new File("myDataDir").getAbsolutePath());
+        zkProp.setProperty("jvm.pause.monitor", "true");
+        zkProp.setProperty("jvm.pause.sleep.time.ms", sleepTime.toString());
+        zkProp.setProperty("jvm.pause.info-threshold.ms", infoTH.toString());
+        try {
+            quorumPeerConfig.parseProperties(zkProp);
+        } catch (IOException | QuorumPeerConfig.ConfigException e) {
+            Assert.fail("Exception while reading config for JvmPauseMonitor");
+        }
+        serverConfig.readFrom(quorumPeerConfig);
+
+        JvmPauseMonitor pauseMonitor = new JvmPauseMonitor(serverConfig);
+        pauseMonitor.serviceStart();
+
+        Assert.assertEquals(sleepTime, Long.valueOf(pauseMonitor.sleepTimeMs));
+        Assert.assertEquals(infoTH, Long.valueOf(pauseMonitor.infoThresholdMs));
+
+        Thread.sleep(1000);
+
+        Assert.assertNotEquals(0L, pauseMonitor.getNumGcInfoThresholdExceeded());
+        Assert.assertEquals(0L, pauseMonitor.getNumGcWarnThresholdExceeded());
+        Assert.assertNotEquals(0L, pauseMonitor.getTotalGcExtraSleepTime());
+    }
+
+    @Test
+    public void testJvmPauseMonitorExceedWarnThreshold() throws InterruptedException {
+        final Long sleepTime = 100L;
+        final Long warnTH = -1L;
+
+        ServerConfig serverConfig = new ServerConfig();
+        QuorumPeerConfig quorumPeerConfig = new QuorumPeerConfig();
+
+        Properties zkProp = new Properties();
+        zkProp.setProperty("dataDir", new File("myDataDir").getAbsolutePath());
+        zkProp.setProperty("jvm.pause.monitor", "true");
+        zkProp.setProperty("jvm.pause.sleep.time.ms", sleepTime.toString());
+        zkProp.setProperty("jvm.pause.warn-threshold.ms", warnTH.toString());
+        try {
+            quorumPeerConfig.parseProperties(zkProp);
+        } catch (IOException | QuorumPeerConfig.ConfigException e) {
+            Assert.fail("Exception while reading config for JvmPauseMonitor");
+        }
+        serverConfig.readFrom(quorumPeerConfig);
+
+        JvmPauseMonitor pauseMonitor = new JvmPauseMonitor(serverConfig);
+        pauseMonitor.serviceStart();
+
+        Assert.assertEquals(sleepTime, Long.valueOf(pauseMonitor.sleepTimeMs));
+        Assert.assertEquals(warnTH, Long.valueOf(pauseMonitor.warnThresholdMs));
+
+        Thread.sleep(1000);
+
+        Assert.assertEquals(0L, pauseMonitor.getNumGcInfoThresholdExceeded());
+        Assert.assertNotEquals(0L, pauseMonitor.getNumGcWarnThresholdExceeded());
+        Assert.assertNotEquals(0L, pauseMonitor.getTotalGcExtraSleepTime());
+    }
+}