text: /**
   * 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.hadoop.hdfs.server.blockmanagement;
  
  import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_MAX_FULL_BLOCK_REPORT_LEASES;
  import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_FULL_BLOCK_REPORT_LEASE_LENGTH_MS;
  
  import com.google.common.base.Joiner;
  import java.util.function.Supplier;
  import com.google.common.util.concurrent.Uninterruptibles;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hdfs.MiniDFSCluster;
  import org.apache.hadoop.hdfs.protocol.DatanodeID;
  import org.apache.hadoop.hdfs.server.protocol.BlockReportContext;
  import org.apache.hadoop.test.GenericTestUtils;
  import org.apache.log4j.Level;
  import org.junit.Assert;
  import org.junit.After;
  import org.junit.BeforeClass;
  import org.junit.Test;
  
  import java.io.IOException;
  import java.util.HashSet;
  import java.util.concurrent.Semaphore;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicReference;
  
  public class TestBlockReportRateLimiting {
    static final Logger LOG =
        LoggerFactory.getLogger(TestBlockReportRateLimiting.class);
  
    private static void setFailure(AtomicReference<String> failure,
                                   String what) {
      failure.compareAndSet("", what);
      LOG.error("Test error: " + what);
    }
  
    @After
    public void restoreNormalBlockManagerFaultInjector() {
      BlockManagerFaultInjector.instance = new BlockManagerFaultInjector();
    }
  
    @BeforeClass
    public static void raiseBlockManagerLogLevels() {
      GenericTestUtils.setLogLevel(BlockManager.LOG, Level.ALL);
      GenericTestUtils.setLogLevel(BlockReportLeaseManager.LOG, Level.ALL);
    }
  
    @Test(timeout=180000)
    public void testRateLimitingDuringDataNodeStartup() throws Exception {
      Configuration conf = new Configuration();
      conf.setInt(DFS_NAMENODE_MAX_FULL_BLOCK_REPORT_LEASES, 1);
      conf.setLong(DFS_NAMENODE_FULL_BLOCK_REPORT_LEASE_LENGTH_MS,
          20L * 60L * 1000L);
  
      final Semaphore fbrSem = new Semaphore(0);
      final HashSet<DatanodeID> expectedFbrDns = new HashSet<>();
      final HashSet<DatanodeID> fbrDns = new HashSet<>();
      final AtomicReference<String> failure = new AtomicReference<String>("");
  
      final BlockManagerFaultInjector injector = new BlockManagerFaultInjector() {
        private int numLeases = 0;
  
        @Override
        public void incomingBlockReportRpc(DatanodeID nodeID,
                      BlockReportContext context) throws IOException {
          LOG.info("Incoming full block report from " + nodeID +
              ".  Lease ID = 0x" + Long.toHexString(context.getLeaseId()));
          if (context.getLeaseId() == 0) {
            setFailure(failure, "Got unexpected rate-limiting-" +
                "bypassing full block report RPC from " + nodeID);
          }
          fbrSem.acquireUninterruptibly();
          synchronized (this) {
            fbrDns.add(nodeID);
            if (!expectedFbrDns.remove(nodeID)) {
              setFailure(failure, "Got unexpected full block report " +
                  "RPC from " + nodeID + ".  expectedFbrDns = " +
                  Joiner.on(", ").join(expectedFbrDns));
            }
            LOG.info("Proceeding with full block report from " +
                nodeID + ".  Lease ID = 0x" +
                Long.toHexString(context.getLeaseId()));
          }
        }
  
        @Override
        public void requestBlockReportLease(DatanodeDescriptor node,
                                            long leaseId) {
          if (leaseId == 0) {
            return;
          }
          synchronized (this) {
            numLeases++;
            expectedFbrDns.add(node);
            LOG.info("requestBlockReportLease(node=" + node +
                ", leaseId=0x" + Long.toHexString(leaseId) + ").  " +
                "expectedFbrDns = " +  Joiner.on(", ").join(expectedFbrDns));
            if (numLeases > 1) {
              setFailure(failure, "More than 1 lease was issued at once.");
            }
          }
        }
  
        @Override
        public void removeBlockReportLease(DatanodeDescriptor node, long leaseId) {
          LOG.info("removeBlockReportLease(node=" + node +
                   ", leaseId=0x" + Long.toHexString(leaseId) + ")");
          synchronized (this) {
            numLeases--;
          }
        }
      };
      BlockManagerFaultInjector.instance = injector;
  
      final int NUM_DATANODES = 5;
      MiniDFSCluster cluster =
          new MiniDFSCluster.Builder(conf).numDataNodes(NUM_DATANODES).build();
      cluster.waitActive();
      for (int n = 1; n <= NUM_DATANODES; n++) {
        LOG.info("Waiting for " + n + " datanode(s) to report in.");
        fbrSem.release();
        Uninterruptibles.sleepUninterruptibly(20, TimeUnit.MILLISECONDS);
        final int currentN = n;
        GenericTestUtils.waitFor(new Supplier<Boolean>() {
          @Override
          public Boolean get() {
            synchronized (injector) {
              if (fbrDns.size() > currentN) {
                setFailure(failure, "Expected at most " + currentN +
                    " datanodes to have sent a block report, but actually " +
                    fbrDns.size() + " have.");
              }
              return (fbrDns.size() >= currentN);
            }
          }
        }, 25, 50000);
      }
      cluster.shutdown();
      Assert.assertEquals("", failure.get());
    }
  
    /**
     * Start a 2-node cluster with only one block report lease.  When the
     * first datanode gets a lease, kill it.  Then wait for the lease to
     * expire, and the second datanode to send a full block report.
     */
    @Test(timeout=180000)
    public void testLeaseExpiration() throws Exception {
      Configuration conf = new Configuration();
      conf.setInt(DFS_NAMENODE_MAX_FULL_BLOCK_REPORT_LEASES, 1);
      conf.setLong(DFS_NAMENODE_FULL_BLOCK_REPORT_LEASE_LENGTH_MS, 100L);
  
      final Semaphore gotFbrSem = new Semaphore(0);
      final AtomicReference<String> failure = new AtomicReference<>();
      final AtomicReference<MiniDFSCluster> cluster =
          new AtomicReference<>();
      final AtomicReference<String> datanodeToStop = new AtomicReference<>();
      final BlockManagerFaultInjector injector = new BlockManagerFaultInjector() {
  
        @Override
        public void incomingBlockReportRpc(DatanodeID nodeID,
                  BlockReportContext context) throws IOException {
          if (context.getLeaseId() == 0) {
            setFailure(failure, "Got unexpected rate-limiting-" +
                "bypassing full block report RPC from " + nodeID);
          }
          if (nodeID.getXferAddr().equals(datanodeToStop.get())) {
            throw new IOException("Injecting failure into block " +
                "report RPC for " + nodeID);
          }
          gotFbrSem.release();
        }
  
        @Override
        public void requestBlockReportLease(DatanodeDescriptor node,
                                            long leaseId) {
          if (leaseId == 0) {
            return;
          }
          datanodeToStop.compareAndSet(null, node.getXferAddr());
        }
  
        @Override
        public void removeBlockReportLease(DatanodeDescriptor node, long leaseId) {
        }
      };
      try {
        BlockManagerFaultInjector.instance = injector;
        cluster.set(new MiniDFSCluster.Builder(conf).numDataNodes(2).build());
        cluster.get().waitActive();
        Assert.assertNotNull(cluster.get().stopDataNode(datanodeToStop.get()));
        gotFbrSem.acquire();
        Assert.assertNull(failure.get());
      } finally {
        if (cluster.get() != null) {
          cluster.get().shutdown();
        }
      }
    }
  }
  