HDFS-14224. RBF: NPE in getContentSummary() for getEcPolicy() in case of multiple destinations. Contributed by Ayush Saxena.

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

@@ -1635,6 +1635,7 @@ public class RouterClientProtocol implements ClientProtocol {
     long quota = 0;
     long spaceConsumed = 0;
     long spaceQuota = 0;
+    String ecPolicy = "";
 
     for (ContentSummary summary : summaries) {
       length += summary.getLength();
@@ -1643,6 +1644,11 @@ public class RouterClientProtocol implements ClientProtocol {
       quota += summary.getQuota();
       spaceConsumed += summary.getSpaceConsumed();
       spaceQuota += summary.getSpaceQuota();
+      // We return from the first response as we assume that the EC policy
+      // of each sub-cluster is same.
+      if (ecPolicy.isEmpty()) {
+        ecPolicy = summary.getErasureCodingPolicy();
+      }
     }
 
     ContentSummary ret = new ContentSummary.Builder()
@@ -1652,6 +1658,7 @@ public class RouterClientProtocol implements ClientProtocol {
         .quota(quota)
         .spaceConsumed(spaceConsumed)
         .spaceQuota(spaceQuota)
+        .erasureCodingPolicy(ecPolicy)
         .build();
     return ret;
   }

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRpcMultiDestination.java

@@ -41,6 +41,7 @@ import java.util.TreeSet;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DistributedFileSystem;
 import org.apache.hadoop.hdfs.protocol.ClientProtocol;
 import org.apache.hadoop.hdfs.protocol.DirectoryListing;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
@@ -229,6 +230,21 @@ public class TestRouterRpcMultiDestination extends TestRouterRpc {
     testRename2(getRouterContext(), filename1, renamedFile, false);
   }
 
+  @Test
+  public void testGetContentSummaryEc() throws Exception {
+    DistributedFileSystem routerDFS =
+        (DistributedFileSystem) getRouterFileSystem();
+    Path dir = new Path("/");
+    String expectedECPolicy = "RS-6-3-1024k";
+    try {
+      routerDFS.setErasureCodingPolicy(dir, expectedECPolicy);
+      assertEquals(expectedECPolicy,
+          routerDFS.getContentSummary(dir).getErasureCodingPolicy());
+    } finally {
+      routerDFS.unsetErasureCodingPolicy(dir);
+    }
+  }
+
   @Test
   public void testSubclusterDown() throws Exception {
     final int totalFiles = 6;