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HADOOP-13200. Implement customizable and configurable erasure coders. Contributed by Tim Yao.

Wei-Chiu Chuang 8 vuotta sitten
vanhempi
commit
872088c6e7
19 muutettua tiedostoa jossa 138 lisäystä ja 76 poistoa
  1. 25 57
      hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/CodecUtil.java
  2. 1 0
      hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/ErasureCodeConstants.java
  3. 12 0
      hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/DummyRawErasureCoderFactory.java
  4. 13 0
      hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/NativeRSRawErasureCoderFactory.java
  5. 13 0
      hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/NativeXORRawErasureCoderFactory.java
  6. 13 0
      hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/RSLegacyRawErasureCoderFactory.java
  7. 13 0
      hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/RSRawErasureCoderFactory.java
  8. 12 0
      hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/RawErasureCoderFactory.java
  9. 13 0
      hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/XORRawErasureCoderFactory.java
  10. 3 3
      hadoop-common-project/hadoop-common/src/main/resources/core-default.xml
  11. 4 4
      hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/erasurecode/TestCodecRawCoderMapping.java
  12. 1 1
      hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/erasurecode/coder/TestHHXORErasureCoder.java
  13. 1 1
      hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/erasurecode/coder/TestRSErasureCoder.java
  14. 9 5
      hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md
  15. 1 1
      hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStripedInputStream.java
  16. 1 1
      hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStripedOutputStream.java
  17. 1 1
      hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStripedOutputStreamWithFailure.java
  18. 1 1
      hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestReconstructStripedFile.java
  19. 1 1
      hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestUnsetAndChangeDirectoryEcPolicy.java

+ 25 - 57
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/CodecUtil.java

@@ -18,8 +18,6 @@
 package org.apache.hadoop.io.erasurecode;
 
 import com.google.common.base.Preconditions;
-import com.google.common.base.Splitter;
-import com.google.common.collect.ImmutableMap;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
@@ -30,18 +28,12 @@ import org.apache.hadoop.io.erasurecode.codec.RSErasureCodec;
 import org.apache.hadoop.io.erasurecode.codec.XORErasureCodec;
 import org.apache.hadoop.io.erasurecode.coder.ErasureDecoder;
 import org.apache.hadoop.io.erasurecode.coder.ErasureEncoder;
-import org.apache.hadoop.io.erasurecode.rawcoder.NativeRSRawErasureCoderFactory;
-import org.apache.hadoop.io.erasurecode.rawcoder.NativeXORRawErasureCoderFactory;
-import org.apache.hadoop.io.erasurecode.rawcoder.RSRawErasureCoderFactory;
-import org.apache.hadoop.io.erasurecode.rawcoder.RSLegacyRawErasureCoderFactory;
 import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureCoderFactory;
 import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureDecoder;
 import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureEncoder;
-import org.apache.hadoop.io.erasurecode.rawcoder.XORRawErasureCoderFactory;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
-import java.util.Map;
 
 /**
  * A codec & coder utility to help create coders conveniently.
@@ -79,27 +71,12 @@ public final class CodecUtil {
   /** Comma separated raw codec name. The first coder is prior to the latter. */
   public static final String IO_ERASURECODE_CODEC_RS_LEGACY_RAWCODERS_KEY =
       IO_ERASURECODE_CODEC + "rs-legacy.rawcoders";
-  public static final String IO_ERASURECODE_CODEC_RS_LEGACY_RAWCODERS_DEFAULT =
-      RSLegacyRawErasureCoderFactory.class.getCanonicalName();
   public static final String IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY =
       IO_ERASURECODE_CODEC + "rs.rawcoders";
-  public static final String IO_ERASURECODE_CODEC_RS_RAWCODERS_DEFAULT =
-      NativeRSRawErasureCoderFactory.class.getCanonicalName() +
-      "," + RSRawErasureCoderFactory.class.getCanonicalName();
 
   /** Raw coder factory for the XOR codec. */
   public static final String IO_ERASURECODE_CODEC_XOR_RAWCODERS_KEY =
       IO_ERASURECODE_CODEC + "xor.rawcoders";
-  public static final String IO_ERASURECODE_CODEC_XOR_RAWCODERS_DEFAULT =
-      NativeXORRawErasureCoderFactory.class.getCanonicalName() +
-      "," + XORRawErasureCoderFactory.class.getCanonicalName();
-
-  // Default coders for each codec names.
-  public static final Map<String, String> DEFAULT_CODERS_MAP = ImmutableMap.of(
-      "rs",         IO_ERASURECODE_CODEC_RS_RAWCODERS_DEFAULT,
-      "rs-legacy",  IO_ERASURECODE_CODEC_RS_LEGACY_RAWCODERS_DEFAULT,
-      "xor",        IO_ERASURECODE_CODEC_XOR_RAWCODERS_DEFAULT
-  );
 
   private CodecUtil() { }
 
@@ -168,70 +145,61 @@ public final class CodecUtil {
   }
 
   private static RawErasureCoderFactory createRawCoderFactory(
-      Configuration conf, String rawCoderFactoryKey) {
+      String coderName, String codecName) {
     RawErasureCoderFactory fact;
-    try {
-      Class<? extends RawErasureCoderFactory> factClass = conf.getClassByName(
-          rawCoderFactoryKey).asSubclass(RawErasureCoderFactory.class);
-      fact = factClass.newInstance();
-    } catch (ClassNotFoundException | InstantiationException |
-        IllegalAccessException e) {
-      throw new RuntimeException("Failed to create raw coder factory", e);
-    }
-
-    if (fact == null) {
-      throw new RuntimeException("Failed to create raw coder factory");
-    }
+    fact = CodecRegistry.getInstance().
+            getCoderByName(codecName, coderName);
 
     return fact;
   }
 
-  // Return comma separated coder names
-  private static String getRawCoders(Configuration conf, String codec) {
-    return conf.get(
-      IO_ERASURECODE_CODEC + codec + ".rawcoders",
-      DEFAULT_CODERS_MAP.getOrDefault(codec, codec)
+  // Return a list of coder names
+  private static String[] getRawCoderNames(
+      Configuration conf, String codecName) {
+    return conf.getStrings(
+      IO_ERASURECODE_CODEC + codecName + ".rawcoders",
+      CodecRegistry.getInstance().getCoderNames(codecName)
     );
   }
 
   private static RawErasureEncoder createRawEncoderWithFallback(
-      Configuration conf, String codec, ErasureCoderOptions coderOptions) {
-    String coders = getRawCoders(conf, codec);
-    for (String factName : Splitter.on(",").split(coders)) {
+      Configuration conf, String codecName, ErasureCoderOptions coderOptions) {
+    String[] rawCoderNames = getRawCoderNames(conf, codecName);
+    for (String rawCoderName : rawCoderNames) {
       try {
-        if (factName != null) {
-          RawErasureCoderFactory fact = createRawCoderFactory(conf,
-              factName);
+        if (rawCoderName != null) {
+          RawErasureCoderFactory fact = createRawCoderFactory(
+              rawCoderName, codecName);
           return fact.createEncoder(coderOptions);
         }
       } catch (LinkageError | Exception e) {
         // Fallback to next coder if possible
-        LOG.warn("Failed to create raw erasure encoder " + factName +
+        LOG.warn("Failed to create raw erasure encoder " + rawCoderName +
             ", fallback to next codec if possible", e);
       }
     }
     throw new IllegalArgumentException("Fail to create raw erasure " +
-       "encoder with given codec: " + codec);
+       "encoder with given codec: " + codecName);
   }
 
   private static RawErasureDecoder createRawDecoderWithFallback(
-          Configuration conf, String codec, ErasureCoderOptions coderOptions) {
-    String coders = getRawCoders(conf, codec);
-    for (String factName : Splitter.on(",").split(coders)) {
+      Configuration conf, String codecName, ErasureCoderOptions coderOptions) {
+    String[] coders = getRawCoderNames(conf, codecName);
+    for (String rawCoderName : coders) {
       try {
-        if (factName != null) {
-          RawErasureCoderFactory fact = createRawCoderFactory(conf,
-              factName);
+        if (rawCoderName != null) {
+          RawErasureCoderFactory fact = createRawCoderFactory(
+              rawCoderName, codecName);
           return fact.createDecoder(coderOptions);
         }
       } catch (LinkageError | Exception e) {
         // Fallback to next coder if possible
-        LOG.warn("Failed to create raw erasure decoder " + factName +
+        LOG.warn("Failed to create raw erasure decoder " + rawCoderName +
             ", fallback to next codec if possible", e);
       }
     }
     throw new IllegalArgumentException("Fail to create raw erasure " +
-            "encoder with given codec: " + codec);
+        "encoder with given codec: " + codecName);
   }
 
   private static ErasureCodec createCodec(Configuration conf,

+ 1 - 0
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/ErasureCodeConstants.java

@@ -25,6 +25,7 @@ public final class ErasureCodeConstants {
   private ErasureCodeConstants() {
   }
 
+  public static final String DUMMY_CODEC_NAME = "dummy";
   public static final String RS_CODEC_NAME = "rs";
   public static final String RS_LEGACY_CODEC_NAME = "rs-legacy";
   public static final String XOR_CODEC_NAME = "xor";

+ 12 - 0
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/DummyRawErasureCoderFactory.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.io.erasurecode.rawcoder;
 
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.io.erasurecode.ErasureCodeConstants;
 import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 
 /**
@@ -25,6 +26,7 @@ import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
  */
 @InterfaceAudience.Private
 public class DummyRawErasureCoderFactory implements RawErasureCoderFactory {
+  public static final String CODER_NAME = "dummy_dummy";
 
   @Override
   public RawErasureEncoder createEncoder(ErasureCoderOptions coderOptions) {
@@ -35,4 +37,14 @@ public class DummyRawErasureCoderFactory implements RawErasureCoderFactory {
   public RawErasureDecoder createDecoder(ErasureCoderOptions coderOptions) {
     return new DummyRawDecoder(coderOptions);
   }
+
+  @Override
+  public String getCoderName() {
+    return CODER_NAME;
+  }
+
+  @Override
+  public String getCodecName() {
+    return ErasureCodeConstants.DUMMY_CODEC_NAME;
+  }
 }

+ 13 - 0
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/NativeRSRawErasureCoderFactory.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.io.erasurecode.rawcoder;
 
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.io.erasurecode.ErasureCodeConstants;
 import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 
 /**
@@ -27,6 +28,8 @@ import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 @InterfaceAudience.Private
 public class NativeRSRawErasureCoderFactory implements RawErasureCoderFactory {
 
+  public static final String CODER_NAME = "rs_native";
+
   @Override
   public RawErasureEncoder createEncoder(ErasureCoderOptions coderOptions) {
     return new NativeRSRawEncoder(coderOptions);
@@ -36,4 +39,14 @@ public class NativeRSRawErasureCoderFactory implements RawErasureCoderFactory {
   public RawErasureDecoder createDecoder(ErasureCoderOptions coderOptions) {
     return new NativeRSRawDecoder(coderOptions);
   }
+
+  @Override
+  public String getCoderName() {
+    return CODER_NAME;
+  }
+
+  @Override
+  public String getCodecName() {
+    return ErasureCodeConstants.RS_CODEC_NAME;
+  }
 }

+ 13 - 0
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/NativeXORRawErasureCoderFactory.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.io.erasurecode.rawcoder;
 
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.io.erasurecode.ErasureCodeConstants;
 import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 
 /**
@@ -27,6 +28,8 @@ import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 @InterfaceAudience.Private
 public class NativeXORRawErasureCoderFactory implements RawErasureCoderFactory {
 
+  public static final String CODER_NAME = "xor_native";
+
   @Override
   public RawErasureEncoder createEncoder(ErasureCoderOptions coderOptions) {
     return new NativeXORRawEncoder(coderOptions);
@@ -36,4 +39,14 @@ public class NativeXORRawErasureCoderFactory implements RawErasureCoderFactory {
   public RawErasureDecoder createDecoder(ErasureCoderOptions coderOptions) {
     return new NativeXORRawDecoder(coderOptions);
   }
+
+  @Override
+  public String getCoderName() {
+    return CODER_NAME;
+  }
+
+  @Override
+  public String getCodecName() {
+    return ErasureCodeConstants.XOR_CODEC_NAME;
+  }
 }

+ 13 - 0
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/RSLegacyRawErasureCoderFactory.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.io.erasurecode.rawcoder;
 
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.io.erasurecode.ErasureCodeConstants;
 import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 
 /**
@@ -26,6 +27,8 @@ import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 @InterfaceAudience.Private
 public class RSLegacyRawErasureCoderFactory implements RawErasureCoderFactory {
 
+  public static final String CODER_NAME = "rs-legacy_java";
+
   @Override
   public RawErasureEncoder createEncoder(ErasureCoderOptions coderOptions) {
     return new RSLegacyRawEncoder(coderOptions);
@@ -35,4 +38,14 @@ public class RSLegacyRawErasureCoderFactory implements RawErasureCoderFactory {
   public RawErasureDecoder createDecoder(ErasureCoderOptions coderOptions) {
     return new RSLegacyRawDecoder(coderOptions);
   }
+
+  @Override
+  public String getCoderName() {
+    return CODER_NAME;
+  }
+
+  @Override
+  public String getCodecName() {
+    return ErasureCodeConstants.RS_LEGACY_CODEC_NAME;
+  }
 }

+ 13 - 0
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/RSRawErasureCoderFactory.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.io.erasurecode.rawcoder;
 
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.io.erasurecode.ErasureCodeConstants;
 import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 
 /**
@@ -26,6 +27,8 @@ import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 @InterfaceAudience.Private
 public class RSRawErasureCoderFactory implements RawErasureCoderFactory {
 
+  public static final String CODER_NAME = "rs_java";
+
   @Override
   public RawErasureEncoder createEncoder(ErasureCoderOptions coderOptions) {
     return new RSRawEncoder(coderOptions);
@@ -35,4 +38,14 @@ public class RSRawErasureCoderFactory implements RawErasureCoderFactory {
   public RawErasureDecoder createDecoder(ErasureCoderOptions coderOptions) {
     return new RSRawDecoder(coderOptions);
   }
+
+  @Override
+  public String getCoderName() {
+    return CODER_NAME;
+  }
+
+  @Override
+  public String getCodecName() {
+    return ErasureCodeConstants.RS_CODEC_NAME;
+  }
 }

+ 12 - 0
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/RawErasureCoderFactory.java

@@ -41,4 +41,16 @@ public interface RawErasureCoderFactory {
    * @return raw erasure decoder
    */
   RawErasureDecoder createDecoder(ErasureCoderOptions coderOptions);
+
+  /**
+   * Get the name of the coder.
+   * @return coder name
+   */
+  String getCoderName();
+
+  /**
+   * Get the name of its codec.
+   * @return codec name
+   */
+  String getCodecName();
 }

+ 13 - 0
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/erasurecode/rawcoder/XORRawErasureCoderFactory.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.io.erasurecode.rawcoder;
 
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.io.erasurecode.ErasureCodeConstants;
 import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 
 /**
@@ -26,6 +27,8 @@ import org.apache.hadoop.io.erasurecode.ErasureCoderOptions;
 @InterfaceAudience.Private
 public class XORRawErasureCoderFactory implements RawErasureCoderFactory {
 
+  public static final String CODER_NAME = "xor_java";
+
   @Override
   public RawErasureEncoder createEncoder(ErasureCoderOptions coderOptions) {
     return new XORRawEncoder(coderOptions);
@@ -35,4 +38,14 @@ public class XORRawErasureCoderFactory implements RawErasureCoderFactory {
   public RawErasureDecoder createDecoder(ErasureCoderOptions coderOptions) {
     return new XORRawDecoder(coderOptions);
   }
+
+  @Override
+  public String getCoderName() {
+    return CODER_NAME;
+  }
+
+  @Override
+  public String getCodecName() {
+    return ErasureCodeConstants.XOR_CODEC_NAME;
+  }
 }

+ 3 - 3
hadoop-common-project/hadoop-common/src/main/resources/core-default.xml

@@ -668,7 +668,7 @@
 
 <property>
   <name>io.erasurecode.codec.rs.rawcoders</name>
-  <value>org.apache.hadoop.io.erasurecode.rawcoder.NativeRSRawErasureCoderFactory,org.apache.hadoop.io.erasurecode.rawcoder.RSRawErasureCoderFactory</value>
+  <value>rs_native,rs_java</value>
   <description>
     Comma separated raw coder implementations for the rs codec. The earlier
     factory is prior to followings in case of failure of creating raw coders.
@@ -677,7 +677,7 @@
 
 <property>
   <name>io.erasurecode.codec.rs-legacy.rawcoders</name>
-  <value>org.apache.hadoop.io.erasurecode.rawcoder.RSLegacyRawErasureCoderFactory</value>
+  <value>rs-legacy_java</value>
   <description>
     Comma separated raw coder implementations for the rs-legacy codec. The earlier
     factory is prior to followings in case of failure of creating raw coders.
@@ -686,7 +686,7 @@
 
 <property>
   <name>io.erasurecode.codec.xor.rawcoders</name>
-  <value>org.apache.hadoop.io.erasurecode.rawcoder.NativeXORRawErasureCoderFactory,org.apache.hadoop.io.erasurecode.rawcoder.XORRawErasureCoderFactory</value>
+  <value>xor_native,xor_java</value>
   <description>
     Comma separated raw coder implementations for the xor codec. The earlier
     factory is prior to followings in case of failure of creating raw coders.

+ 4 - 4
hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/erasurecode/TestCodecRawCoderMapping.java

@@ -28,6 +28,7 @@ import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureDecoder;
 import org.apache.hadoop.io.erasurecode.rawcoder.RawErasureEncoder;
 import org.apache.hadoop.io.erasurecode.rawcoder.XORRawDecoder;
 import org.apache.hadoop.io.erasurecode.rawcoder.XORRawEncoder;
+import org.apache.hadoop.io.erasurecode.rawcoder.XORRawErasureCoderFactory;
 import org.apache.hadoop.test.GenericTestUtils;
 import org.junit.Assert;
 import org.junit.Before;
@@ -104,8 +105,8 @@ public class TestCodecRawCoderMapping {
     ErasureCoderOptions coderOptions = new ErasureCoderOptions(
             numDataUnit, numParityUnit);
     conf.set(CodecUtil.IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY,
-        RSRawErasureCoderFactory.class.getCanonicalName() +
-        "," + NativeRSRawErasureCoderFactory.class.getCanonicalName());
+        RSRawErasureCoderFactory.CODER_NAME +
+        "," + NativeRSRawErasureCoderFactory.CODER_NAME);
     // should return default raw coder of rs codec
     RawErasureEncoder encoder = CodecUtil.createRawEncoder(
             conf, ErasureCodeConstants.RS_CODEC_NAME, coderOptions);
@@ -133,8 +134,7 @@ public class TestCodecRawCoderMapping {
     ErasureCoderOptions coderOptions = new ErasureCoderOptions(
             numDataUnit, numParityUnit);
     conf.set(CodecUtil.IO_ERASURECODE_CODEC_XOR_RAWCODERS_KEY,
-        "invalid-codec," +
-        "org.apache.hadoop.io.erasurecode.rawcoder.XORRawErasureCoderFactory");
+        "invalid-codec," + XORRawErasureCoderFactory.CODER_NAME);
     // should return second coder specified by IO_ERASURECODE_CODEC_CODERS
     RawErasureEncoder encoder = CodecUtil.createRawEncoder(
             conf, ErasureCodeConstants.XOR_CODEC_NAME, coderOptions);

+ 1 - 1
hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/erasurecode/coder/TestHHXORErasureCoder.java

@@ -51,7 +51,7 @@ public class TestHHXORErasureCoder extends TestHHErasureCoderBase {
      */
     Configuration conf = new Configuration();
     conf.set(CodecUtil.IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY,
-        RSRawErasureCoderFactory.class.getCanonicalName());
+        RSRawErasureCoderFactory.CODER_NAME);
     prepare(conf, 10, 4, new int[]{0}, new int[0]);
 
     testCoding(true);

+ 1 - 1
hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/erasurecode/coder/TestRSErasureCoder.java

@@ -58,7 +58,7 @@ public class TestRSErasureCoder extends TestErasureCoderBase {
      */
     Configuration conf = new Configuration();
     conf.set(CodecUtil.IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY,
-        RSRawErasureCoderFactory.class.getCanonicalName());
+        RSRawErasureCoderFactory.CODER_NAME);
     prepare(conf, 10, 4, new int[]{0}, new int[0]);
 
     testCoding(true);

+ 9 - 5
hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md

@@ -117,11 +117,15 @@ Deployment
   be more appropriate. If the administrator only cares about node-level fault-tolerance, `RS-10-4-64k` would still be appropriate as long as
   there are at least 14 DataNodes in the cluster.
 
-  The codec implementation for Reed-Solomon and XOR can be configured with the following client and DataNode configuration keys:
-  `io.erasurecode.codec.rs.rawcoder` for the default RS codec,
-  `io.erasurecode.codec.rs-legacy.rawcoder` for the legacy RS codec,
-  `io.erasurecode.codec.xor.rawcoder` for the XOR codec.
-  The default implementations for all of these codecs are pure Java. For default RS codec, there is also a native implementation which leverages Intel ISA-L library to improve the performance of codec. For XOR codec, a native implementation which leverages Intel ISA-L library to improve the performance of codec is also supported. Please refer to section "Enable Intel ISA-L" for more detail information.
+  The codec implementations for Reed-Solomon and XOR can be configured with the following client and DataNode configuration keys:
+  `io.erasurecode.codec.rs.rawcoders` for the default RS codec,
+  `io.erasurecode.codec.rs-legacy.rawcoders` for the legacy RS codec,
+  `io.erasurecode.codec.xor.rawcoders` for the XOR codec.
+  User can also configure self-defined codec with configuration key like:
+  `io.erasurecode.codec.self-defined-codec.rawcoders`.
+  The values for these key are lists of coder names with a fall-back mechanism.
+  All these codecs have implementations in pure Java. For default RS codec, there is also a native implementation which leverages Intel ISA-L library to improve the performance of codec. For XOR codec, a native implementation which leverages Intel ISA-L library to improve the performance of codec is also supported. Please refer to section "Enable Intel ISA-L" for more detail information.
+  The default implementation for RS Legacy is pure Java, and the default implementations for default RS and XOR are native implementations using Intel ISA-L library.
 
   Erasure coding background recovery work on the DataNodes can also be tuned via the following configuration parameters:
 

+ 1 - 1
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStripedInputStream.java

@@ -98,7 +98,7 @@ public class TestDFSStripedInputStream {
     if (ErasureCodeNative.isNativeCodeLoaded()) {
       conf.set(
           CodecUtil.IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY,
-          NativeRSRawErasureCoderFactory.class.getCanonicalName());
+          NativeRSRawErasureCoderFactory.CODER_NAME);
     }
     SimulatedFSDataset.setFactory(conf);
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(

+ 1 - 1
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStripedOutputStream.java

@@ -85,7 +85,7 @@ public class TestDFSStripedOutputStream {
     if (ErasureCodeNative.isNativeCodeLoaded()) {
       conf.set(
           CodecUtil.IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY,
-          NativeRSRawErasureCoderFactory.class.getCanonicalName());
+          NativeRSRawErasureCoderFactory.CODER_NAME);
     }
     DFSTestUtil.enableAllECPolicies(conf);
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDNs).build();

+ 1 - 1
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStripedOutputStreamWithFailure.java

@@ -214,7 +214,7 @@ public class TestDFSStripedOutputStreamWithFailure {
     if (ErasureCodeNative.isNativeCodeLoaded()) {
       conf.set(
           CodecUtil.IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY,
-          NativeRSRawErasureCoderFactory.class.getCanonicalName());
+          NativeRSRawErasureCoderFactory.CODER_NAME);
     }
     DFSTestUtil.enableAllECPolicies(conf);
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(numDNs).build();

+ 1 - 1
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestReconstructStripedFile.java

@@ -100,7 +100,7 @@ public class TestReconstructStripedFile {
     if (ErasureCodeNative.isNativeCodeLoaded()) {
       conf.set(
           CodecUtil.IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY,
-          NativeRSRawErasureCoderFactory.class.getCanonicalName());
+          NativeRSRawErasureCoderFactory.CODER_NAME);
     }
     conf.set(DFSConfigKeys.DFS_NAMENODE_EC_POLICIES_ENABLED_KEY,
         StripedFileTestUtil.getDefaultECPolicy().getName());

+ 1 - 1
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestUnsetAndChangeDirectoryEcPolicy.java

@@ -68,7 +68,7 @@ public class TestUnsetAndChangeDirectoryEcPolicy {
     if (ErasureCodeNative.isNativeCodeLoaded()) {
       conf.set(
           CodecUtil.IO_ERASURECODE_CODEC_RS_RAWCODERS_KEY,
-          NativeRSRawErasureCoderFactory.class.getCanonicalName());
+          NativeRSRawErasureCoderFactory.CODER_NAME);
     }
     DFSTestUtil.enableAllECPolicies(conf);
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(