content: /*
   * 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.cassandra.distributed.test;
  
  import java.io.IOException;
  import java.lang.management.ManagementFactory;
  import java.nio.file.FileSystems;
  import java.nio.file.Path;
  import java.sql.Date;
  import java.text.SimpleDateFormat;
  import java.util.concurrent.TimeUnit;
  import java.util.function.Consumer;
  import javax.management.MBeanServer;
  import javax.management.MBeanServerConnection;
  import javax.management.remote.JMXConnector;
  
  import org.apache.cassandra.distributed.shared.Uninterruptibles;
  import org.apache.cassandra.distributed.shared.InstanceClassLoader;
  import org.junit.Assert;
  import org.junit.Ignore;
  import org.junit.Test;
  
  import com.sun.management.HotSpotDiagnosticMXBean;
  import org.apache.cassandra.distributed.Cluster;
  import org.apache.cassandra.distributed.api.ConsistencyLevel;
  import org.apache.cassandra.distributed.api.IInstanceConfig;
  import org.apache.cassandra.distributed.api.IInvokableInstance;
  import org.apache.cassandra.distributed.shared.JMXUtil;
  import org.apache.cassandra.io.util.File;
  import org.apache.cassandra.utils.FBUtilities;
  
  import static org.apache.cassandra.distributed.api.Feature.GOSSIP;
  import static org.apache.cassandra.distributed.api.Feature.JMX;
  import static org.apache.cassandra.distributed.api.Feature.NATIVE_PROTOCOL;
  import static org.apache.cassandra.distributed.api.Feature.NETWORK;
  import static org.apache.cassandra.distributed.test.jmx.JMXTestsUtil.testAllValidGetters;
  import static org.apache.cassandra.utils.FBUtilities.now;
  import static org.hamcrest.Matchers.lessThanOrEqualTo;
  import static org.hamcrest.Matchers.startsWith;
  
  /* Resource Leak Test - useful when tracking down issues with in-JVM framework cleanup.
   * All objects referencing the InstanceClassLoader need to be garbage collected or
   * the JVM runs out of metaspace. This test also calls out to lsof to check which
   * file handles are still opened.
   *
   * This is intended to be a burn type test where it is run outside of the test suites
   * when a problem is detected (like OutOfMetaspace exceptions).
   *
   * Currently this test demonstrates that the InstanceClassLoader is cleaned up (load up
   * the final hprof and check that the class loaders are not reachable from a GC root),
   * but it shows that the file handles for Data/Index files are being leaked.
   */
  
  public class ResourceLeakTest extends TestBaseImpl
  {
      // Parameters to adjust while hunting for leaks
      // numTestLoops should be >= 3, and numClusterNodes >= 2, when committed to source control.
      // This ensures the instance class loader assertions will fail quickly and reliably when a
      // new InstanceClassLoader leak is introduced.
      final int numTestLoops = 3;
      final int numClusterNodes = 2;
      final boolean dumpEveryLoop = true;   // Dump heap & possibly files every loop
      final boolean dumpFileHandles = false; // Call lsof whenever dumping resources
      final long finalWaitMillis = 0L;       // Number of millis to wait before final resource dump to give gc a chance
  
      static final SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmss");
      static final String when = format.format(Date.from(now()));
  
      static String outputFilename(String base, String description, String extension)
      {
          Path p = FileSystems.getDefault().getPath("build", "test",
                                                    String.join("-", when, base, description) + extension);
          return p.toString();
      }
  
      /**
       * Retrieves the process ID or <code>null</code> if the process ID cannot be retrieved.
       * @return the process ID or <code>null</code> if the process ID cannot be retrieved.
       *
       * (Duplicated from HeapUtils to avoid refactoring older releases where this test is useful).
       */
      private static Long getProcessId()
      {
          long pid = FBUtilities.getSystemInfo().getPid();
  
          if (pid >= 0)
              return Long.valueOf(pid);
  
          return getProcessIdFromJvmName();
      }
  
      /**
       * Retrieves the process ID from the JVM name.
       * @return the process ID or <code>null</code> if the process ID cannot be retrieved.
       */
      private static Long getProcessIdFromJvmName()
      {
          // the JVM name in Oracle JVMs is: '<pid>@<hostname>' but this might not be the case on all JVMs
          String jvmName = ManagementFactory.getRuntimeMXBean().getName();
          try
          {
              return Long.parseLong(jvmName.split("@")[0]);
          }
          catch (NumberFormatException e)
          {
              // ignore
          }
          return null;
      }
  
      static void dumpHeap(String description, boolean live) throws IOException
      {
          MBeanServer server = ManagementFactory.getPlatformMBeanServer();
          HotSpotDiagnosticMXBean mxBean = ManagementFactory.newPlatformMXBeanProxy(
          server, "com.sun.management:type=HotSpotDiagnostic", HotSpotDiagnosticMXBean.class);
          mxBean.dumpHeap(outputFilename("heap", description, ".hprof"), live);
      }
  
      static void dumpOpenFiles(String description) throws IOException, InterruptedException
      {
          long pid = getProcessId();
          ProcessBuilder map = new ProcessBuilder("/usr/sbin/lsof", "-p", Long.toString(pid));
          File output = new File(outputFilename("lsof", description, ".txt"));
          map.redirectOutput(output.toJavaIOFile());
          map.redirectErrorStream(true);
          map.start().waitFor();
      }
  
      void dumpResources(String description) throws IOException, InterruptedException
      {
          dumpHeap(description, false);
          if (dumpFileHandles)
          {
              dumpOpenFiles(description);
          }
      }
  
      static void testJmx(Cluster cluster)
      {
          try
          {
              for (IInvokableInstance instance : cluster.get(1, cluster.size()))
              {
                  IInstanceConfig config = instance.config();
                  try (JMXConnector jmxc = JMXUtil.getJmxConnector(config, 5))
                  {
                      MBeanServerConnection mbsc = jmxc.getMBeanServerConnection();
                      // instances get their default domain set to their IP address, so us it
                      // to check that we are actually connecting to the correct instance
                      String defaultDomain = mbsc.getDefaultDomain();
                      Assert.assertThat(defaultDomain, startsWith(JMXUtil.getJmxHost(config) + ":" + config.jmxPort()));
                  }
              }
              testAllValidGetters(cluster, null);
          }
          catch (Exception e)
          {
              throw new RuntimeException(e);
          }
      }
  
      void checkForInstanceClassLoaderLeaks(int maxAllowableInstances, int loop) throws IOException, InterruptedException {
          for (int i = 0; InstanceClassLoader.getApproximateLiveLoaderCount(true) > maxAllowableInstances && i < 120; i++) {
              Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);
          }
          int approximateLiveLoaderCount = InstanceClassLoader.getApproximateLiveLoaderCount(true);
          if (approximateLiveLoaderCount > maxAllowableInstances) {
              dumpResources(String.format("InstanceClassLoader max reached at loop %d", loop));
              Assert.assertThat("InstanceClassLoader leak detected",
                      approximateLiveLoaderCount,
                      lessThanOrEqualTo(maxAllowableInstances));
          }
      }
  
      void doTest(Consumer<IInstanceConfig> updater) throws Throwable
      {
          doTest(updater, ignored -> {}, false);
      }
  
      void doTest(Consumer<IInstanceConfig> updater, Consumer<Cluster> actionToPerform, boolean shouldCheckForClassloaderLeaks) throws Throwable
      {
          for (int loop = 0; loop < numTestLoops; loop++)
          {
              System.out.println(String.format("========== Starting loop %03d ========", loop));
              Cluster.Builder builder = builder();
              try (Cluster cluster = (Cluster) builder.withNodes(numClusterNodes).withConfig(updater).start())
              {
                  init(cluster);
                  String tableName = "tbl" + loop;
                  cluster.schemaChange("CREATE TABLE " + KEYSPACE + "." + tableName + " (pk int, ck int, v int, PRIMARY KEY (pk, ck))");
                  cluster.coordinator(1).execute("INSERT INTO " + KEYSPACE + "." + tableName + "(pk,ck,v) VALUES (0,0,0)", ConsistencyLevel.ALL);
                  cluster.get(1).flush(KEYSPACE);
                  actionToPerform.accept(cluster);
                  if (dumpEveryLoop)
                  {
                      dumpResources(String.format("loop%03d", loop));
                  }
                  // We add 2 to the number of allowed classloaders to provide some wiggle room, as GC is non-deterministic
                  // and some threads don't always shut down in time
                  if (shouldCheckForClassloaderLeaks)
                  {
                      checkForInstanceClassLoaderLeaks(numClusterNodes + 2, loop);
                  }
              }
              catch (AssertionError ae) {
                  throw ae;
              }
              catch (Throwable tr)
              {
                  System.out.println("Dumping resources for exception: " + tr);
                  tr.printStackTrace();
                  dumpResources("exception");
              }
              System.runFinalization();
              System.gc();
              System.out.println(String.format("========== Completed loop %03d ========", loop));
          }
      }
  
      @Ignore("Only run if debugging an issue")
      @Test
      public void looperTest() throws Throwable
      {
          doTest(config -> {});
          System.runFinalization();
          System.gc();
          Thread.sleep(finalWaitMillis);
          dumpResources("final");
      }
  
      @Ignore("Only run if debugging an issue")
      @Test
      public void looperGossipNetworkTest() throws Throwable
      {
          doTest(config -> config.with(GOSSIP).with(NETWORK));
          System.runFinalization();
          System.gc();
          Thread.sleep(finalWaitMillis);
          dumpResources("final-gossip-network");
      }
  
      @Ignore("Only run if debugging an issue")
      @Test
      public void looperNativeTest() throws Throwable
      {
          doTest(config -> config.with(NATIVE_PROTOCOL));
          System.runFinalization();
          System.gc();
          Thread.sleep(finalWaitMillis);
          dumpResources("final-native");
      }
  
      @Ignore("Only run if debugging an issue")
      @Test
      public void looperJmxTest() throws Throwable
      {
          doTest(config -> config.with(JMX), ResourceLeakTest::testJmx, false);
          System.runFinalization();
          System.gc();
          Thread.sleep(finalWaitMillis);
          dumpResources("final-jmx");
      }
  
      /**
       * This test is enabled in an attempt to automatically catch InstanceClassloader leaks.
       * Depending on the type of leak, we may need to actually exercise functionality like JMX or Native
       * beyond just enabling the feature, so we use the "everything" test even though it may take longer to run.
       */
      @Ignore
      @Test
      public void looperEverythingTest() throws Throwable
      {
          doTest(config -> config.with(NETWORK, GOSSIP, NATIVE_PROTOCOL, JMX), // Exclude `BLANK_GOSSIP`
                 cluster -> {
                     NativeProtocolTest.testNativeRequests(cluster);
                     testJmx(cluster);
                 }, true);
          System.runFinalization();
          System.gc();
          Thread.sleep(finalWaitMillis);
          dumpResources("final-everything");
      }
  }
  