HDFS-17595. [ARR] ErasureCoding supports asynchronous rpc.

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/AsyncErasureCoding.java

@@ -0,0 +1,178 @@
+/**
+ * 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.federation.router;
+
+import org.apache.hadoop.hdfs.protocol.AddErasureCodingPolicyResponse;
+import org.apache.hadoop.hdfs.protocol.ECBlockGroupStats;
+import org.apache.hadoop.hdfs.protocol.ECTopologyVerifierResult;
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicyInfo;
+import org.apache.hadoop.hdfs.server.federation.resolver.ActiveNamenodeResolver;
+import org.apache.hadoop.hdfs.server.federation.resolver.FederationNamespaceInfo;
+import org.apache.hadoop.hdfs.server.federation.resolver.RemoteLocation;
+import org.apache.hadoop.hdfs.server.federation.router.async.ApplyFunction;
+import org.apache.hadoop.hdfs.server.namenode.NameNode;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import static org.apache.hadoop.hdfs.server.federation.router.RouterRpcServer.merge;
+import static org.apache.hadoop.hdfs.server.federation.router.async.AsyncUtil.asyncApply;
+import static org.apache.hadoop.hdfs.server.federation.router.async.AsyncUtil.asyncReturn;
+
+public class AsyncErasureCoding extends ErasureCoding{
+  /** RPC server to receive client calls. */
+  private final RouterRpcServer rpcServer;
+  /** RPC clients to connect to the Namenodes. */
+  private final RouterRpcClient rpcClient;
+  /** Interface to identify the active NN for a nameservice or blockpool ID. */
+  private final ActiveNamenodeResolver namenodeResolver;
+
+  public AsyncErasureCoding(RouterRpcServer server) {
+    super(server);
+    this.rpcServer = server;
+    this.rpcClient =  this.rpcServer.getRPCClient();
+    this.namenodeResolver = this.rpcClient.getNamenodeResolver();
+  }
+
+  public ErasureCodingPolicyInfo[] getErasureCodingPolicies()
+      throws IOException {
+    rpcServer.checkOperation(NameNode.OperationCategory.READ);
+
+    RemoteMethod method = new RemoteMethod("getErasureCodingPolicies");
+    Set<FederationNamespaceInfo> nss = namenodeResolver.getNamespaces();
+
+    rpcClient.invokeConcurrent(
+        nss, method, true, false, ErasureCodingPolicyInfo[].class);
+    asyncApply(
+        (ApplyFunction<Map<FederationNamespaceInfo, ErasureCodingPolicyInfo[]>, ErasureCodingPolicyInfo[]>)
+            ret -> merge(ret, ErasureCodingPolicyInfo.class));
+
+    return asyncReturn(ErasureCodingPolicyInfo[].class);
+  }
+
+  @Override
+  public Map getErasureCodingCodecs() throws IOException {
+    rpcServer.checkOperation(NameNode.OperationCategory.READ);
+
+    RemoteMethod method = new RemoteMethod("getErasureCodingCodecs");
+    Set<FederationNamespaceInfo> nss = namenodeResolver.getNamespaces();
+
+    rpcClient.invokeConcurrent(
+        nss, method, true, false, Map.class);
+
+    asyncApply((ApplyFunction<Map<FederationNamespaceInfo, Map>, Map>) retCodecs -> {
+      Map<String, String> ret = new HashMap<>();
+      Object obj = retCodecs;
+      @SuppressWarnings("unchecked")
+      Map<FederationNamespaceInfo, Map<String, String>> results =
+          (Map<FederationNamespaceInfo, Map<String, String>>)obj;
+      Collection<Map<String, String>> allCodecs = results.values();
+      for (Map<String, String> codecs : allCodecs) {
+        ret.putAll(codecs);
+      }
+      return ret;
+    });
+
+    return asyncReturn(Map.class);
+  }
+
+  @Override
+  public AddErasureCodingPolicyResponse[] addErasureCodingPolicies(
+      ErasureCodingPolicy[] policies) throws IOException {
+    rpcServer.checkOperation(NameNode.OperationCategory.WRITE);
+
+    RemoteMethod method = new RemoteMethod("addErasureCodingPolicies",
+        new Class<?>[] {ErasureCodingPolicy[].class}, new Object[] {policies});
+    Set<FederationNamespaceInfo> nss = namenodeResolver.getNamespaces();
+
+    rpcClient.invokeConcurrent(
+        nss, method, true, false, AddErasureCodingPolicyResponse[].class);
+
+    asyncApply(
+        (ApplyFunction<Map<FederationNamespaceInfo, AddErasureCodingPolicyResponse[]>,
+            AddErasureCodingPolicyResponse[]>) ret -> {
+          return merge(ret, AddErasureCodingPolicyResponse.class);
+        });
+    return asyncReturn(AddErasureCodingPolicyResponse[].class);
+  }
+
+  @Override
+  public ErasureCodingPolicy getErasureCodingPolicy(String src)
+      throws IOException {
+    rpcServer.checkOperation(NameNode.OperationCategory.READ);
+
+    final List<RemoteLocation> locations =
+        rpcServer.getLocationsForPath(src, false, false);
+    RemoteMethod remoteMethod = new RemoteMethod("getErasureCodingPolicy",
+        new Class<?>[] {String.class}, new RemoteParam());
+    rpcClient.invokeSequential(
+        locations, remoteMethod, null, null);
+
+    asyncApply(ret -> {
+      return (ErasureCodingPolicy) ret;
+    });
+
+    return asyncReturn(ErasureCodingPolicy.class);
+  }
+
+
+  @Override
+  public ECTopologyVerifierResult getECTopologyResultForPolicies(
+      String[] policyNames) throws IOException {
+    RemoteMethod method = new RemoteMethod("getECTopologyResultForPolicies",
+        new Class<?>[] {String[].class}, new Object[] {policyNames});
+    Set<FederationNamespaceInfo> nss = namenodeResolver.getNamespaces();
+    if (nss.isEmpty()) {
+      throw new IOException("No namespace availaible.");
+    }
+
+    rpcClient.invokeConcurrent(nss, method, true, false,
+        ECTopologyVerifierResult.class);
+    asyncApply((ApplyFunction<Map<FederationNamespaceInfo, ECTopologyVerifierResult>, ECTopologyVerifierResult>) ret -> {
+      for (Map.Entry<FederationNamespaceInfo, ECTopologyVerifierResult> entry : ret
+          .entrySet()) {
+        if (!entry.getValue().isSupported()) {
+          return entry.getValue();
+        }
+      }
+      // If no negative result, return the result from the first namespace.
+      return ret.get(nss.iterator().next());
+    });
+    return asyncReturn(ECTopologyVerifierResult.class);
+  }
+
+  @Override
+  public ECBlockGroupStats getECBlockGroupStats() throws IOException {
+    rpcServer.checkOperation(NameNode.OperationCategory.READ);
+
+    RemoteMethod method = new RemoteMethod("getECBlockGroupStats");
+    Set<FederationNamespaceInfo> nss = namenodeResolver.getNamespaces();
+    rpcClient.invokeConcurrent(
+        nss, method, true, false, ECBlockGroupStats.class);
+
+    asyncApply((ApplyFunction<Map<FederationNamespaceInfo, ECBlockGroupStats>, ECBlockGroupStats>) allStats -> {
+      return ECBlockGroupStats.merge(allStats.values());
+    });
+    return asyncReturn(ECBlockGroupStats.class);
+  }
+}