HDDS-1586. Allow Ozone RPC client to read with topology awareness.

Author: ChenSammi

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientGrpc.java

@@ -23,6 +23,7 @@
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdds.HddsUtils;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
+import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos;
 import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos.ContainerCommandRequestProto;
 import org.apache.hadoop.hdds.protocol.datanode.proto.ContainerProtos.ContainerCommandResponseProto;
 import org.apache.hadoop.hdds.protocol.datanode.proto.XceiverClientProtocolServiceGrpc;
@@ -64,7 +65,7 @@
 import java.util.concurrent.TimeoutException;
 
 /**
- * A Client for the storageContainer protocol.
+ * A Client for the storageContainer protocol for read object data.
  */
 public class XceiverClientGrpc extends XceiverClientSpi {
   static final Logger LOG = LoggerFactory.getLogger(XceiverClientGrpc.class);
@@ -76,6 +77,7 @@ public class XceiverClientGrpc extends XceiverClientSpi {
   private final Semaphore semaphore;
   private boolean closed = false;
   private SecurityConfig secConfig;
+  private final boolean topologyAwareRead;
 
   /**
    * Constructs a client that can communicate with the Container framework on
@@ -96,16 +98,20 @@ public XceiverClientGrpc(Pipeline pipeline, Configuration config) {
     this.metrics = XceiverClientManager.getXceiverClientMetrics();
     this.channels = new HashMap<>();
     this.asyncStubs = new HashMap<>();
+    this.topologyAwareRead = Boolean.parseBoolean(config.get(
+        ScmConfigKeys.DFS_NETWORK_TOPOLOGY_AWARE_READ_ENABLED,
+        ScmConfigKeys.DFS_NETWORK_TOPOLOGY_AWARE_READ_ENABLED_DEFAULT));
   }
 
   /**
    * To be used when grpc token is not enabled.
    */
   @Override
   public void connect() throws Exception {
-    // leader by default is the 1st datanode in the datanode list of pipleline
-    DatanodeDetails dn = this.pipeline.getFirstNode();
-    // just make a connection to the 1st datanode at the beginning
+    // connect to the closest node, if closest node doesn't exist, delegate to
+    // first node, which is usually the leader in the pipeline.
+    DatanodeDetails dn = this.pipeline.getClosestNode();
+    // just make a connection to the picked datanode at the beginning
     connectToDatanode(dn, null);
   }
 
@@ -114,9 +120,11 @@ public void connect() throws Exception {
    */
   @Override
   public void connect(String encodedToken) throws Exception {
-    // leader by default is the 1st datanode in the datanode list of pipleline
-    DatanodeDetails dn = this.pipeline.getFirstNode();
-    // just make a connection to the 1st datanode at the beginning
+    // connect to the closest node, if closest node doesn't exist, delegate to
+    // first node, which is usually the leader in the pipeline.
+    DatanodeDetails dn;
+    dn = this.pipeline.getClosestNode();
+    // just make a connection to the picked datanode at the beginning
     connectToDatanode(dn, encodedToken);
   }
 
@@ -132,7 +140,8 @@ private void connectToDatanode(DatanodeDetails dn, String encodedToken)
 
     // Add credential context to the client call
     String userName = UserGroupInformation.getCurrentUser().getShortUserName();
-    LOG.debug("Connecting to server Port : " + dn.getIpAddress());
+    LOG.debug("Nodes in pipeline : {}", pipeline.getNodes().toString());
+    LOG.debug("Connecting to server : {}", dn.getIpAddress());
     NettyChannelBuilder channelBuilder =
         NettyChannelBuilder.forAddress(dn.getIpAddress(), port).usePlaintext()
             .maxInboundMessageSize(OzoneConsts.OZONE_SCM_CHUNK_MAX_SIZE)
@@ -252,7 +261,15 @@ private XceiverClientReply sendCommandWithRetry(
     // TODO: cache the correct leader info in here, so that any subsequent calls
     // should first go to leader
     XceiverClientReply reply = new XceiverClientReply(null);
-    for (DatanodeDetails dn : pipeline.getNodes()) {
+    List<DatanodeDetails> datanodeList;
+    if ((request.getCmdType() == ContainerProtos.Type.ReadChunk ||
+        request.getCmdType() == ContainerProtos.Type.GetSmallFile) &&
+        topologyAwareRead) {
+      datanodeList = pipeline.getNodesInOrder();
+    } else {
+      datanodeList = pipeline.getNodes();
+    }
+    for (DatanodeDetails dn : datanodeList) {
       try {
         LOG.debug("Executing command " + request + " on datanode " + dn);
         // In case the command gets retried on a 2nd datanode,
@@ -349,6 +366,8 @@ private XceiverClientReply sendCommandAsync(
       reconnect(dn, token);
     }
 
+    LOG.debug("Send command {} to datanode {}", request.getCmdType().toString(),
+        dn.getNetworkFullPath());
     final CompletableFuture<ContainerCommandResponseProto> replyFuture =
         new CompletableFuture<>();
     semaphore.acquire();

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/XceiverClientManager.java

@@ -29,6 +29,8 @@
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos;
 import org.apache.hadoop.ozone.OzoneSecurityUtil;
 import org.apache.hadoop.security.UserGroupInformation;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -57,14 +59,16 @@
  * not being used for a period of time.
  */
 public class XceiverClientManager implements Closeable {
-
+  private static final Logger LOG =
+      LoggerFactory.getLogger(XceiverClientManager.class);
   //TODO : change this to SCM configuration class
   private final Configuration conf;
   private final Cache<String, XceiverClientSpi> clientCache;
   private final boolean useRatis;
 
   private static XceiverClientMetrics metrics;
   private boolean isSecurityEnabled;
+  private final boolean topologyAwareRead;
   /**
    * Creates a new XceiverClientManager.
    *
@@ -98,6 +102,9 @@ public void onRemoval(
               }
             }
           }).build();
+    topologyAwareRead = Boolean.parseBoolean(conf.get(
+        ScmConfigKeys.DFS_NETWORK_TOPOLOGY_AWARE_READ_ENABLED,
+        ScmConfigKeys.DFS_NETWORK_TOPOLOGY_AWARE_READ_ENABLED_DEFAULT));
   }
 
   @VisibleForTesting
@@ -118,12 +125,32 @@ public Cache<String, XceiverClientSpi> getClientCache() {
    */
   public XceiverClientSpi acquireClient(Pipeline pipeline)
       throws IOException {
+    return acquireClient(pipeline, false);
+  }
+
+  /**
+   * Acquires a XceiverClientSpi connected to a container for read.
+   *
+   * If there is already a cached XceiverClientSpi, simply return
+   * the cached otherwise create a new one.
+   *
+   * @param pipeline the container pipeline for the client connection
+   * @return XceiverClientSpi connected to a container
+   * @throws IOException if a XceiverClientSpi cannot be acquired
+   */
+  public XceiverClientSpi acquireClientForReadData(Pipeline pipeline)
+      throws IOException {
+    return acquireClient(pipeline, true);
+  }
+
+  private XceiverClientSpi acquireClient(Pipeline pipeline, boolean read)
+      throws IOException {
     Preconditions.checkNotNull(pipeline);
     Preconditions.checkArgument(pipeline.getNodes() != null);
     Preconditions.checkArgument(!pipeline.getNodes().isEmpty());
 
     synchronized (clientCache) {
-      XceiverClientSpi info = getClient(pipeline);
+      XceiverClientSpi info = getClient(pipeline, read);
       info.incrementReference();
       return info;
     }
@@ -136,12 +163,28 @@ public XceiverClientSpi acquireClient(Pipeline pipeline)
    * @param invalidateClient if true, invalidates the client in cache
    */
   public void releaseClient(XceiverClientSpi client, boolean invalidateClient) {
+    releaseClient(client, invalidateClient, false);
+  }
+
+  /**
+   * Releases a read XceiverClientSpi after use.
+   *
+   * @param client client to release
+   * @param invalidateClient if true, invalidates the client in cache
+   */
+  public void releaseClientForReadData(XceiverClientSpi client,
+      boolean invalidateClient) {
+    releaseClient(client, invalidateClient, true);
+  }
+
+  private void releaseClient(XceiverClientSpi client, boolean invalidateClient,
+      boolean read) {
     Preconditions.checkNotNull(client);
     synchronized (clientCache) {
       client.decrementReference();
       if (invalidateClient) {
         Pipeline pipeline = client.getPipeline();
-        String key = pipeline.getId().getId().toString() + pipeline.getType();
+        String key = getPipelineCacheKey(pipeline, read);
         XceiverClientSpi cachedClient = clientCache.getIfPresent(key);
         if (cachedClient == client) {
           clientCache.invalidate(key);
@@ -150,11 +193,13 @@ public void releaseClient(XceiverClientSpi client, boolean invalidateClient) {
     }
   }
 
-  private XceiverClientSpi getClient(Pipeline pipeline)
+  private XceiverClientSpi getClient(Pipeline pipeline, boolean forRead)
       throws IOException {
     HddsProtos.ReplicationType type = pipeline.getType();
     try {
-      String key = pipeline.getId().getId().toString() + type;
+      // create different client for read different pipeline node based on
+      // network topology
+      String key = getPipelineCacheKey(pipeline, forRead);
       // Append user short name to key to prevent a different user
       // from using same instance of xceiverClient.
       key = isSecurityEnabled ?
@@ -184,6 +229,19 @@ public XceiverClientSpi call() throws Exception {
     }
   }
 
+  private String getPipelineCacheKey(Pipeline pipeline, boolean forRead) {
+    String key = pipeline.getId().getId().toString() + pipeline.getType();
+    if (topologyAwareRead && forRead) {
+      try {
+        key += pipeline.getClosestNode().getHostName();
+      } catch (IOException e) {
+        LOG.error("Failed to get closest node to create pipeline cache key:" +
+            e.getMessage());
+      }
+    }
+    return key;
+  }
+
   /**
    * Close and remove all the cached clients.
    */

hadoop-hdds/client/src/main/java/org/apache/hadoop/hdds/scm/storage/BlockInputStream.java

@@ -151,7 +151,7 @@ protected List<ChunkInfo> getChunkInfos() throws IOException {
       pipeline = Pipeline.newBuilder(pipeline)
           .setType(HddsProtos.ReplicationType.STAND_ALONE).build();
     }
-    xceiverClient = xceiverClientManager.acquireClient(pipeline);
+    xceiverClient = xceiverClientManager.acquireClientForReadData(pipeline);
     boolean success = false;
     List<ChunkInfo> chunks;
     try {
@@ -170,7 +170,7 @@ protected List<ChunkInfo> getChunkInfos() throws IOException {
       success = true;
     } finally {
       if (!success) {
-        xceiverClientManager.releaseClient(xceiverClient, false);
+        xceiverClientManager.releaseClientForReadData(xceiverClient, false);
       }
     }
 

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/protocol/DatanodeDetails.java

@@ -76,6 +76,7 @@ protected DatanodeDetails(DatanodeDetails datanodeDetails) {
     this.ipAddress = datanodeDetails.ipAddress;
     this.hostName = datanodeDetails.hostName;
     this.ports = datanodeDetails.ports;
+    this.setNetworkName(datanodeDetails.getNetworkName());
   }
 
   /**
@@ -192,6 +193,12 @@ public static DatanodeDetails getFromProtoBuf(
       builder.addPort(newPort(
           Port.Name.valueOf(port.getName().toUpperCase()), port.getValue()));
     }
+    if (datanodeDetailsProto.hasNetworkLocation()) {
+      builder.setNetworkLocation(datanodeDetailsProto.getNetworkLocation());
+    }
+    if (datanodeDetailsProto.hasNetworkName()) {
+      builder.setNetworkName(datanodeDetailsProto.getNetworkName());
+    }
     return builder.build();
   }
 
@@ -213,6 +220,7 @@ public HddsProtos.DatanodeDetailsProto getProtoBufMessage() {
       builder.setCertSerialId(certSerialId);
     }
     builder.setNetworkLocation(getNetworkLocation());
+    builder.setNetworkName(getNetworkName());
 
     for (Port port : ports) {
       builder.addPorts(HddsProtos.Port.newBuilder()
@@ -268,6 +276,7 @@ public static final class Builder {
     private String id;
     private String ipAddress;
     private String hostName;
+    private String networkName;
     private String networkLocation;
     private List<Port> ports;
     private String certSerialId;
@@ -313,6 +322,17 @@ public Builder setHostName(String host) {
       return this;
     }
 
+    /**
+     * Sets the network name of DataNode.
+     *
+     * @param name network name
+     * @return DatanodeDetails.Builder
+     */
+    public Builder setNetworkName(String name) {
+      this.networkName = name;
+      return this;
+    }
+
     /**
      * Sets the network location of DataNode.
      *
@@ -358,8 +378,12 @@ public DatanodeDetails build() {
       if (networkLocation == null) {
         networkLocation = NetConstants.DEFAULT_RACK;
       }
-      return new DatanodeDetails(id, ipAddress, hostName, networkLocation,
-          ports, certSerialId);
+      DatanodeDetails dn = new DatanodeDetails(id, ipAddress, hostName,
+          networkLocation, ports, certSerialId);
+      if (networkName != null) {
+        dn.setNetworkName(networkName);
+      }
+      return dn;
     }
   }
 

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/ScmConfigKeys.java

@@ -368,6 +368,10 @@ public final class ScmConfigKeys {
       "ozone.scm.network.topology.schema.file";
   public static final String OZONE_SCM_NETWORK_TOPOLOGY_SCHEMA_FILE_DEFAULT =
       "network-topology-default.xml";
+  public static final String DFS_NETWORK_TOPOLOGY_AWARE_READ_ENABLED =
+      "dfs.network.topology.aware.read.enable";
+  public static final String DFS_NETWORK_TOPOLOGY_AWARE_READ_ENABLED_DEFAULT =
+      "true";
 
   public static final String HDDS_TRACING_ENABLED = "hdds.tracing.enabled";
   public static final boolean HDDS_TRACING_ENABLED_DEFAULT = true;

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/net/NetworkTopology.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.hdds.scm.net;
 
 import java.util.Collection;
+import java.util.List;
 
 /**
  * The interface defines a network topology.
@@ -246,5 +247,6 @@ Node getNode(int leafIndex, String scope, String excludedScope,
    * @param nodes     Available replicas with the requested data
    * @param activeLen Number of active nodes at the front of the array
    */
-  void sortByDistanceCost(Node reader, Node[] nodes, int activeLen);
+  List<? extends Node> sortByDistanceCost(Node reader,
+      List<? extends Node> nodes, int activeLen);
 }