HDFS-14124. EC : Support EC Commands (set/get/unset EcPolicy) via WebHdfs. Contributed by Ayush Saxena.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/JsonUtilClient.java

@@ -675,6 +675,17 @@ public static BlockStoragePolicy toBlockStoragePolicy(Map<?, ?> m) {
         replicationFallbacks, copyOnCreateFile.booleanValue());
   }
 
+  public static ErasureCodingPolicy toECPolicy(Map<?, ?> m) {
+    byte id = ((Number) m.get("id")).byteValue();
+    String name = (String) m.get("name");
+    String codec = (String) m.get("codecName");
+    int cellsize = ((Number) m.get("cellSize")).intValue();
+    int dataunits = ((Number) m.get("numDataUnits")).intValue();
+    int parityunits = ((Number) m.get("numParityUnits")).intValue();
+    ECSchema ecs = new ECSchema(codec, dataunits, parityunits);
+    return new ErasureCodingPolicy(name, ecs, cellsize, id);
+  }
+
   private static StorageType[] toStorageTypes(List<?> list) {
     if (list == null) {
       return null;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -94,6 +94,7 @@
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
 import org.apache.hadoop.hdfs.protocol.BlockStoragePolicy;
 import org.apache.hadoop.hdfs.protocol.DirectoryListing;
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.SnapshotDiffReport;
@@ -1311,15 +1312,47 @@ public void allowSnapshot(final Path p) throws IOException {
   }
 
   public void enableECPolicy(String policyName) throws IOException {
+    statistics.incrementWriteOps(1);
+    storageStatistics.incrementOpCounter(OpType.ENABLE_EC_POLICY);
     final HttpOpParam.Op op = PutOpParam.Op.ENABLEECPOLICY;
     new FsPathRunner(op, null, new ECPolicyParam(policyName)).run();
   }
 
   public void disableECPolicy(String policyName) throws IOException {
+    statistics.incrementWriteOps(1);
+    storageStatistics.incrementOpCounter(OpType.DISABLE_EC_POLICY);
     final HttpOpParam.Op op = PutOpParam.Op.DISABLEECPOLICY;
     new FsPathRunner(op, null, new ECPolicyParam(policyName)).run();
   }
 
+  public void setErasureCodingPolicy(Path p, String policyName)
+      throws IOException {
+    statistics.incrementWriteOps(1);
+    storageStatistics.incrementOpCounter(OpType.SET_EC_POLICY);
+    final HttpOpParam.Op op = PutOpParam.Op.SETECPOLICY;
+    new FsPathRunner(op, p, new ECPolicyParam(policyName)).run();
+  }
+
+  public void unsetErasureCodingPolicy(Path p) throws IOException {
+    statistics.incrementWriteOps(1);
+    storageStatistics.incrementOpCounter(OpType.UNSET_EC_POLICY);
+    final HttpOpParam.Op op = PostOpParam.Op.UNSETECPOLICY;
+    new FsPathRunner(op, p).run();
+  }
+
+  public ErasureCodingPolicy getErasureCodingPolicy(Path p)
+      throws IOException {
+    statistics.incrementReadOps(1);
+    storageStatistics.incrementOpCounter(OpType.GET_EC_POLICY);
+    final HttpOpParam.Op op =GetOpParam.Op.GETECPOLICY;
+    return new FsPathResponseRunner<ErasureCodingPolicy>(op, p) {
+      @Override
+      ErasureCodingPolicy decodeResponse(Map<?, ?> json) throws IOException {
+        return JsonUtilClient.toECPolicy((Map<?, ?>) json);
+      }
+    }.run();
+  }
+
   @Override
   public Path createSnapshot(final Path path, final String snapshotName)
       throws IOException {

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/GetOpParam.java

@@ -53,6 +53,8 @@ public enum Op implements HttpOpParam.Op {
     GETALLSTORAGEPOLICY(false, HttpURLConnection.HTTP_OK),
     GETSTORAGEPOLICY(false, HttpURLConnection.HTTP_OK),
 
+    GETECPOLICY(false, HttpURLConnection.HTTP_OK),
+
     NULL(false, HttpURLConnection.HTTP_NOT_IMPLEMENTED),
 
     CHECKACCESS(false, HttpURLConnection.HTTP_OK),

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/PostOpParam.java

@@ -29,6 +29,8 @@ public enum Op implements HttpOpParam.Op {
 
     TRUNCATE(false, HttpURLConnection.HTTP_OK),
 
+    UNSETECPOLICY(false, HttpURLConnection.HTTP_OK),
+
     UNSETSTORAGEPOLICY(false, HttpURLConnection.HTTP_OK),
 
     NULL(false, HttpURLConnection.HTTP_NOT_IMPLEMENTED);

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/PutOpParam.java

@@ -48,6 +48,7 @@ public enum Op implements HttpOpParam.Op {
 
     ENABLEECPOLICY(false, HttpURLConnection.HTTP_OK),
     DISABLEECPOLICY(false, HttpURLConnection.HTTP_OK),
+    SETECPOLICY(false, HttpURLConnection.HTTP_OK),
 
     ALLOWSNAPSHOT(false, HttpURLConnection.HTTP_OK),
     DISALLOWSNAPSHOT(false, HttpURLConnection.HTTP_OK),

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java

@@ -79,6 +79,7 @@
 import org.apache.hadoop.hdfs.protocol.ClientProtocol;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.DirectoryListing;
+import org.apache.hadoop.hdfs.protocol.ErasureCodingPolicy;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.protocol.SnapshotDiffReport;
@@ -804,12 +805,14 @@ protected Response put(
       validateOpParams(op, ecpolicy);
       cp.enableErasureCodingPolicy(ecpolicy.getValue());
       return Response.ok().type(MediaType.APPLICATION_OCTET_STREAM).build();
-
     case DISABLEECPOLICY:
       validateOpParams(op, ecpolicy);
       cp.disableErasureCodingPolicy(ecpolicy.getValue());
       return Response.ok().type(MediaType.APPLICATION_OCTET_STREAM).build();
-
+    case SETECPOLICY:
+      validateOpParams(op, ecpolicy);
+      cp.setErasureCodingPolicy(fullpath, ecpolicy.getValue());
+      return Response.ok().type(MediaType.APPLICATION_OCTET_STREAM).build();
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }
@@ -937,6 +940,9 @@ protected Response post(
       cp.unsetStoragePolicy(fullpath);
       return Response.ok().build();
     }
+    case UNSETECPOLICY:
+      cp.unsetErasureCodingPolicy(fullpath);
+      return Response.ok().build();
     default:
       throw new UnsupportedOperationException(op + " is not supported");
     }
@@ -1247,6 +1253,11 @@ protected Response get(
       final String js = JsonUtil.toJsonString(storagePolicy);
       return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
     }
+    case GETECPOLICY: {
+      ErasureCodingPolicy ecpolicy = cp.getErasureCodingPolicy(fullpath);
+      final String js = JsonUtil.toJsonString(ecpolicy);
+      return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
+    }
     case GETSERVERDEFAULTS: {
       // Since none of the server defaults values are hot reloaded, we can
       // cache the output of serverDefaults.

hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/WebHDFS.md

@@ -53,6 +53,7 @@ The HTTP REST API supports the complete [FileSystem](../../api/org/apache/hadoop
     * [`GETSNAPSHOTDIFF`](#Get_Snapshot_Diff)
     * [`GETSNAPSHOTTABLEDIRECTORYLIST`](#Get_Snapshottable_Directory_List)
     * [`GETFILEBLOCKLOCATIONS`](#Get_File_Block_Locations) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).getFileBlockLocations)
+    * [`GETECPOLICY`](#Get_EC_Policy) (see [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).getErasureCodingPolicy)
 *   HTTP PUT
     * [`CREATE`](#Create_and_Write_to_a_File) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).create)
     * [`MKDIRS`](#Make_a_Directory) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).mkdirs)
@@ -73,11 +74,13 @@ The HTTP REST API supports the complete [FileSystem](../../api/org/apache/hadoop
     * [`SETSTORAGEPOLICY`](#Set_Storage_Policy) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).setStoragePolicy)
     * [`ENABLEECPOLICY`](#Enable_EC_Policy) (see [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).enablePolicy)
     * [`DISABLEECPOLICY`](#Disable_EC_Policy) (see [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).disablePolicy)
+    * [`SETECPOLICY`](#Set_EC_Policy) (see [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).setErasureCodingPolicy)
 *   HTTP POST
     * [`APPEND`](#Append_to_a_File) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).append)
     * [`CONCAT`](#Concat_Files) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).concat)
     * [`TRUNCATE`](#Truncate_a_File) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).truncate)
     * [`UNSETSTORAGEPOLICY`](#Unset_Storage_Policy) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).unsetStoragePolicy)
+    * [`UNSETECPOLICY`](#Unset_EC_Policy) (see [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).unsetErasureCodingPolicy)
 *   HTTP DELETE
     * [`DELETE`](#Delete_a_FileDirectory) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).delete)
     * [`DELETESNAPSHOT`](#Delete_Snapshot) (see [FileSystem](../../api/org/apache/hadoop/fs/FileSystem.html).deleteSnapshot)
@@ -1285,7 +1288,7 @@ Erasure Coding Operations
         HTTP/1.1 200 OK
         Content-Length: 0
 
-See also: [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).enablePolicy)
+See also: [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).enablePolicy
 
 ### Disable EC Policy
 
@@ -1299,7 +1302,68 @@ See also: [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).
         HTTP/1.1 200 OK
         Content-Length: 0
 
-See also: [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).disablePolicy)
+See also: [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).disablePolicy
+
+### Set EC Policy
+
+* Submit a HTTP PUT request.
+
+        curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETECPOLICY
+                                      &ecpolicy=<policy>"
+
+    The client receives a response with zero content length:
+
+        HTTP/1.1 200 OK
+        Content-Length: 0
+
+See also: [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).setErasureCodingPolicy
+
+### Get EC Policy
+
+* Submit a HTTP GET request.
+
+        curl -i -X GET "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETECPOLICY
+                                     "
+
+   The client receives a response with a [`ECPolicy` JSON object](#ECPolicy_JSON_Schema):
+
+
+        {
+            "name": "RS-10-4-1024k",
+            "schema":
+            {
+            "codecName": "rs",
+            "numDataUnits": 10,
+            "numParityUnits": 4,
+            "extraOptions": {}
+            }
+            "cellSize": 1048576,
+            "id":5,
+            "codecname":"rs",
+            "numDataUnits": 10,
+            "numParityUnits": 4,
+            "replicationpolicy":false,
+            "systemPolicy":true
+
+        }
+
+
+
+See also: [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).getErasureCodingPolicy
+
+### Unset EC Policy
+
+* Submit a HTTP POST request.
+
+        curl -i -X POST "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=UNSETECPOLICY
+                                     "
+
+    The client receives a response with zero content length:
+
+        HTTP/1.1 200 OK
+        Content-Length: 0
+
+See also: [HDFSErasureCoding](./HDFSErasureCoding.html#Administrative_commands).unsetErasureCodingPolicy
 
 Snapshot Operations
 -------------------
@@ -2173,6 +2237,26 @@ var blockStoragePolicyProperties =
   }
 };
 ```
+### ECPolicy JSON Schema
+
+```json
+{
+  "name": "RS-10-4-1024k",
+  schema {
+           "codecName": "rs",
+           "numDataUnits": 10,
+           "numParityUnits": 4,
+           "extraOptions": {}
+          }
+  "cellSize": 1048576,
+  "id":5,
+  "codecname":"rs",
+  "numDataUnits": 10,
+  "numParityUnits": 4,
+  "replicationpolicy":false,
+  "systemPolicy":true
+}
+```
 
 ### BlockStoragePolicies JSON Schema
 
@@ -2244,6 +2328,7 @@ A `BlockStoragePolicies` JSON object represents an array of `BlockStoragePolicy`
 }
 ```
 
+
 #### DiffReport Entries
 
 JavaScript syntax is used to define `diffReportEntries` so that it can be referred in `SnapshotDiffReport` JSON schema.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHDFS.java

@@ -1623,7 +1623,7 @@ private void checkECPolicyState(Collection<ErasureCodingPolicyInfo> policies,
 
   // Test For Enable/Disable EC Policy in DFS.
   @Test
-  public void testEnableDisableECPolicy() throws Exception {
+  public void testECPolicyCommands() throws Exception {
     Configuration conf = new HdfsConfiguration();
     try (MiniDFSCluster cluster =
         new MiniDFSCluster.Builder(conf).numDataNodes(0).build()) {
@@ -1632,12 +1632,24 @@ public void testEnableDisableECPolicy() throws Exception {
       final WebHdfsFileSystem webHdfs = WebHdfsTestUtil
           .getWebHdfsFileSystem(conf, WebHdfsConstants.WEBHDFS_SCHEME);
       String policy = "RS-10-4-1024k";
-
       // Check for Enable EC policy via WEBHDFS.
       dfs.disableErasureCodingPolicy(policy);
       checkECPolicyState(dfs.getAllErasureCodingPolicies(), policy, "disable");
-      webHdfs.enableECPolicy("RS-10-4-1024k");
+      webHdfs.enableECPolicy(policy);
       checkECPolicyState(dfs.getAllErasureCodingPolicies(), policy, "enable");
+      Path dir = new Path("/tmp");
+      dfs.mkdirs(dir);
+      // Check for Set EC policy via WEBHDFS
+      assertNull(dfs.getErasureCodingPolicy(dir));
+      webHdfs.setErasureCodingPolicy(dir, policy);
+      assertEquals(policy, dfs.getErasureCodingPolicy(dir).getName());
+
+      // Check for Get EC policy via WEBHDFS
+      assertEquals(policy, webHdfs.getErasureCodingPolicy(dir).getName());
+
+      // Check for Unset EC policy via WEBHDFS
+      webHdfs.unsetErasureCodingPolicy(dir);
+      assertNull(dfs.getErasureCodingPolicy(dir));
 
       // Check for Disable EC policy via WEBHDFS.
       webHdfs.disableECPolicy(policy);