Implement new VM pause monitor

community/common/src/main/java/org/neo4j/util/Preconditions.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2002-2018 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.neo4j.util;
+
+public final class Preconditions
+{
+    private Preconditions()
+    {
+        // util class
+    }
+
+    public static long requireNonNegative( long value )
+    {
+        if ( value < 0 )
+        {
+            throw new IllegalArgumentException( "Expected non-negative integer value, got " + value );
+        }
+        return value;
+    }
+
+    public static long requirePositive( long value )
+    {
+        if ( value < 1 )
+        {
+            throw new IllegalArgumentException( "Expected positive integer value, got " + value );
+        }
+        return value;
+    }
+}

community/kernel/src/main/java/org/neo4j/graphdb/factory/GraphDatabaseSettings.java

@@ -43,7 +43,6 @@
 import org.neo4j.kernel.configuration.Settings;
 import org.neo4j.kernel.configuration.Title;
 import org.neo4j.kernel.configuration.ssl.SslPolicyConfigValidator;
-import org.neo4j.kernel.impl.cache.MonitorGc;
 import org.neo4j.logging.Level;
 import org.neo4j.logging.LogTimeZone;
 
@@ -617,16 +616,13 @@ public class GraphDatabaseSettings implements LoadableConfig
     public static final Setting<String> forced_kernel_id = buildSetting( "unsupported.dbms.kernel_id", STRING, NO_DEFAULT ).constraint(
             illegalValueMessage( "has to be a valid kernel identifier", matches( "[a-zA-Z0-9]*" ) ) ).build();
 
-    @SuppressWarnings( "unused" )
-    @Description( "Amount of time in ms the GC monitor thread will wait before taking another measurement." )
     @Internal
-    public static final Setting<Duration> gc_monitor_interval = MonitorGc.Configuration.gc_monitor_wait_time;
+    public static final Setting<Duration> vm_pause_monitor_measurement_duration =
+            setting( "unsupported.vm_pause_monitor.measurement_duration", DURATION, "100ms" );
 
-    @SuppressWarnings( "unused" )
-    @Description( "The amount of time in ms the monitor thread has to be blocked before logging a message it was " +
-            "blocked." )
     @Internal
-    public static final Setting<Duration> gc_monitor_block_threshold = MonitorGc.Configuration.gc_monitor_threshold;
+    public static final Setting<Duration> vm_pause_monitor_stall_alert_threshold =
+            setting( "unsupported.vm_pause_monitor.stall_alert_threshold", DURATION, "100ms" );
 
     @Description( "Relationship count threshold for considering a node to be dense" )
     public static final Setting<Integer> dense_node_threshold =

community/kernel/src/main/java/org/neo4j/kernel/impl/cache/MonitorGc.java → community/kernel/src/main/java/org/neo4j/kernel/impl/cache/VmPauseMonitorComponent.java

@@ -19,32 +19,19 @@
  */
 package org.neo4j.kernel.impl.cache;
 
-import java.time.Duration;
-
-import org.neo4j.graphdb.config.Setting;
+import org.neo4j.graphdb.factory.GraphDatabaseSettings;
 import org.neo4j.kernel.configuration.Config;
 import org.neo4j.kernel.lifecycle.Lifecycle;
+import org.neo4j.kernel.monitoring.VmPauseMonitor;
 import org.neo4j.logging.Log;
 
-import static org.neo4j.kernel.configuration.Settings.DURATION;
-import static org.neo4j.kernel.configuration.Settings.setting;
-import static org.neo4j.kernel.impl.cache.MeasureDoNothing.loggingMonitor;
-
-public class MonitorGc implements Lifecycle
+public class VmPauseMonitorComponent implements Lifecycle
 {
-    public static class Configuration
-    {
-        public static final Setting<Duration> gc_monitor_wait_time = setting( "unsupported.dbms.gc_monitor_wait_time",
-                DURATION, "100ms" );
-        public static final Setting<Duration> gc_monitor_threshold = setting("unsupported.dbms.gc_monitor_threshold",
-                DURATION, "200ms" );
-    }
-
     private final Config config;
     private final Log log;
-    private volatile MeasureDoNothing monitorGc;
+    private volatile VmPauseMonitor vmPauseMonitor;
 
-    public MonitorGc( Config config, Log log )
+    public VmPauseMonitorComponent( Config config, Log log )
     {
         this.config = config;
         this.log = log;
@@ -58,17 +45,19 @@ public void init()
     @Override
     public void start()
     {
-        monitorGc = new MeasureDoNothing( "neo4j.PauseMonitor", loggingMonitor( log ),
-                config.get( Configuration.gc_monitor_wait_time ).toMillis(),
-                config.get( Configuration.gc_monitor_threshold ).toMillis() );
-        monitorGc.start();
+        vmPauseMonitor = new VmPauseMonitor(
+                config.get( GraphDatabaseSettings.vm_pause_monitor_measurement_duration ).toMillis(),
+                config.get( GraphDatabaseSettings.vm_pause_monitor_stall_alert_threshold ).toMillis(),
+                log, vmPauseInfo -> log.debug( "Detected VM stop-the-world pause: {}", vmPauseInfo )
+        );
+        vmPauseMonitor.start();
     }
 
     @Override
     public void stop()
     {
-        monitorGc.stopMeasuring();
-        monitorGc = null;
+        vmPauseMonitor.stop();
+        vmPauseMonitor = null;
     }
 
     @Override

community/kernel/src/main/java/org/neo4j/kernel/impl/factory/DataSourceModule.java

@@ -50,11 +50,9 @@
 import org.neo4j.kernel.impl.api.dbms.NonTransactionalDbmsOperations;
 import org.neo4j.kernel.impl.api.explicitindex.InternalAutoIndexing;
 import org.neo4j.kernel.impl.api.index.IndexingService;
-import org.neo4j.kernel.impl.cache.MonitorGc;
+import org.neo4j.kernel.impl.cache.VmPauseMonitorComponent;
 import org.neo4j.kernel.impl.core.DatabasePanicEventGenerator;
 import org.neo4j.kernel.impl.core.EmbeddedProxySPI;
-import org.neo4j.kernel.impl.core.NodeProxy;
-import org.neo4j.kernel.impl.core.RelationshipProxy;
 import org.neo4j.kernel.impl.core.RelationshipTypeTokenHolder;
 import org.neo4j.kernel.impl.core.StartupStatisticsProvider;
 import org.neo4j.kernel.impl.core.ThreadToStatementContextBridge;
@@ -65,7 +63,6 @@
 import org.neo4j.kernel.impl.proc.ProcedureTransactionProvider;
 import org.neo4j.kernel.impl.proc.Procedures;
 import org.neo4j.kernel.impl.proc.TerminationGuardProvider;
-import org.neo4j.kernel.impl.proc.TypeMappers.DefaultValueConverter;
 import org.neo4j.kernel.impl.query.QueryExecutionEngine;
 import org.neo4j.kernel.impl.store.StoreId;
 import org.neo4j.kernel.impl.transaction.log.files.LogFileCreationMonitor;
@@ -209,7 +206,7 @@ public DataSourceModule( final PlatformModule platformModule, EditionModule edit
 
         dataSourceManager.register( neoStoreDataSource );
 
-        life.add( new MonitorGc( config, logging.getInternalLog( MonitorGc.class ) ) );
+        life.add( new VmPauseMonitorComponent( config, logging.getInternalLog( VmPauseMonitorComponent.class ) ) );
 
         life.add( new PublishPageCacheTracerMetricsAfterStart( platformModule.tracers.pageCursorTracerSupplier ) );