HDDS-13963. Atomic Create-If-Not-Exists

hadoop-hdds/common/src/main/java/org/apache/hadoop/ozone/OzoneConsts.java

@@ -315,6 +315,7 @@ public final class OzoneConsts {
   public static final String TENANT = "tenant";
   public static final String USER_PREFIX = "userPrefix";
   public static final String REWRITE_GENERATION = "rewriteGeneration";
+  public static final long EXPECTED_GEN_CREATE_IF_NOT_EXISTS = -1L;
   public static final String FROM_SNAPSHOT = "fromSnapshot";
   public static final String TO_SNAPSHOT = "toSnapshot";
   public static final String TOKEN = "token";

hadoop-ozone/client/src/main/java/org/apache/hadoop/ozone/client/OzoneBucket.java

@@ -1029,8 +1029,8 @@ public List<OzoneFileStatus> listStatus(String keyName, boolean recursive,
    *
    * @param prefix Optional string to filter for the selected keys.
    */
-  public OzoneMultipartUploadList listMultipartUploads(String prefix, 
-      String keyMarker, String uploadIdMarker, int maxUploads) 
+  public OzoneMultipartUploadList listMultipartUploads(String prefix,
+      String keyMarker, String uploadIdMarker, int maxUploads)
       throws IOException {
     return proxy.listMultipartUploads(volumeName, getName(), prefix, keyMarker, uploadIdMarker, maxUploads);
   }

hadoop-ozone/client/src/main/java/org/apache/hadoop/ozone/client/rpc/RpcClient.java

@@ -677,7 +677,7 @@ public void createBucket(
       builder.setDefaultReplicationConfig(defaultReplicationConfig);
     }
 
-    String replicationType = defaultReplicationConfig == null 
+    String replicationType = defaultReplicationConfig == null
         ? "server-side default replication type"
         : defaultReplicationConfig.getType().toString();
 
@@ -1315,7 +1315,7 @@ public List<OzoneBucket> listBuckets(String volumeName, String bucketPrefix,
     List<OmBucketInfo> buckets = ozoneManagerClient.listBuckets(
         volumeName, prevBucket, bucketPrefix, maxListResult, hasSnapshot);
 
-    return buckets.stream().map(bucket -> 
+    return buckets.stream().map(bucket ->
             OzoneBucket.newBuilder(conf, this)
                 .setVolumeName(bucket.getVolumeName())
                 .setName(bucket.getBucketName())

hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/exceptions/OMException.java

@@ -208,7 +208,7 @@ public enum ResultCodes {
     USER_MISMATCH, // Error code when requested user name passed is different
     // from remote user.
 
-    INVALID_PART, // When part name is not found or not matching with partname 
+    INVALID_PART, // When part name is not found or not matching with partname
     // in OM MPU partInfo.
 
     INVALID_PART_ORDER, // When list of parts mentioned to complete MPU are not
@@ -267,7 +267,7 @@ public enum ResultCodes {
     UNAUTHORIZED,
 
     S3_SECRET_ALREADY_EXISTS,
-    
+
     INVALID_PATH,
     TOO_MANY_BUCKETS,
     KEY_UNDER_LEASE_RECOVERY,

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/client/rpc/OzoneRpcClientTests.java

@@ -35,11 +35,13 @@
 import static org.apache.hadoop.ozone.OzoneConfigKeys.OZONE_SCM_BLOCK_SIZE_DEFAULT;
 import static org.apache.hadoop.ozone.OzoneConsts.DEFAULT_OM_UPDATE_ID;
 import static org.apache.hadoop.ozone.OzoneConsts.ETAG;
+import static org.apache.hadoop.ozone.OzoneConsts.EXPECTED_GEN_CREATE_IF_NOT_EXISTS;
 import static org.apache.hadoop.ozone.OzoneConsts.GB;
 import static org.apache.hadoop.ozone.OzoneConsts.MD5_HASH;
 import static org.apache.hadoop.ozone.OzoneConsts.OZONE_URI_DELIMITER;
 import static org.apache.hadoop.ozone.client.OzoneClientTestUtils.assertKeyContent;
 import static org.apache.hadoop.ozone.om.OMConfigKeys.OZONE_DIR_DELETING_SERVICE_INTERVAL;
+import static org.apache.hadoop.ozone.om.exceptions.OMException.ResultCodes.KEY_ALREADY_EXISTS;
 import static org.apache.hadoop.ozone.om.exceptions.OMException.ResultCodes.KEY_NOT_FOUND;
 import static org.apache.hadoop.ozone.om.exceptions.OMException.ResultCodes.NO_SUCH_MULTIPART_UPLOAD_ERROR;
 import static org.apache.hadoop.ozone.om.exceptions.OMException.ResultCodes.PARTIAL_RENAME;
@@ -1370,6 +1372,54 @@ void rewriteFailsDueToOutdatedGenerationAtCommit(BucketLayout layout) throws IOE
     assertUnchanged(keyInfo, ozoneManager.lookupKey(keyArgs));
   }
 
+  @ParameterizedTest
+  @EnumSource
+  void rewriteFailsWhenKeyExists(BucketLayout layout) throws IOException {
+    checkFeatureEnable(OzoneManagerVersion.ATOMIC_REWRITE_KEY);
+    OzoneBucket bucket = createBucket(layout);
+    OzoneKeyDetails key1Details = createTestKey(bucket, "key1", "value".getBytes(UTF_8));
+    OzoneOutputStream key2Out = openTestKey(bucket, "key2", "value");
+    OzoneOutputStream key3Out = openTestKey(bucket, "key3", "value");
+
+    // Test 1: Rewrite with -1 fails when key is already committed
+    OMException e = assertThrows(OMException.class, () -> {
+      bucket.rewriteKey(
+          key1Details.getName(),
+          key1Details.getDataSize(),
+          EXPECTED_GEN_CREATE_IF_NOT_EXISTS,
+          RatisReplicationConfig.getInstance(HddsProtos.ReplicationFactor.ONE),
+          key1Details.getMetadata());
+    });
+
+    assertEquals(KEY_ALREADY_EXISTS, e.getResult());
+    assertThat(e).hasMessageContaining("Key already exists");
+
+    // Test 2: Rewrite with -1 succeeds when key is open but not yet committed
+    assertDoesNotThrow(() -> {
+      bucket.rewriteKey("key2",
+          1024,
+          EXPECTED_GEN_CREATE_IF_NOT_EXISTS,
+          RatisReplicationConfig.getInstance(HddsProtos.ReplicationFactor.ONE),
+          singletonMap("key", "value"));
+    });
+    key2Out.close();
+
+    // Test 3: After rewrite completes, attempting to rewrite again with -1 fails
+    key3Out.write("value".getBytes(UTF_8));
+    key3Out.close();
+
+    e = assertThrows(OMException.class, () -> {
+      bucket.rewriteKey("key2",
+          1024,
+          EXPECTED_GEN_CREATE_IF_NOT_EXISTS,
+          RatisReplicationConfig.getInstance(HddsProtos.ReplicationFactor.ONE),
+          singletonMap("key", "value"));
+    });
+
+    assertEquals(KEY_ALREADY_EXISTS, e.getResult());
+    assertThat(e).hasMessageContaining("Key already exists");
+  }
+
   @ParameterizedTest
   @EnumSource
   void cannotRewriteDeletedKey(BucketLayout layout) throws IOException {
@@ -4385,6 +4435,12 @@ private void completeMultipartUpload(OzoneBucket bucket, String keyName,
     assertNotNull(omMultipartUploadCompleteInfo.getHash());
   }
 
+  private OzoneOutputStream openTestKey(OzoneBucket bucket, String keyName, String keyValue) throws IOException {
+    return bucket.createKey(keyName, keyValue.getBytes(UTF_8).length,
+        RatisReplicationConfig.getInstance(HddsProtos.ReplicationFactor.ONE),
+        singletonMap("key", RandomStringUtils.secure().nextAscii(10)));
+  }
+
   private OzoneKeyDetails createTestKey(OzoneBucket bucket) throws IOException {
     return createTestKey(bucket, getTestName(), UUID.randomUUID().toString());
   }

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/request/key/OMKeyCommitRequest.java

@@ -616,14 +616,23 @@ protected void validateAtomicRewrite(OmKeyInfo existing, OmKeyInfo toCommit, Map
     if (toCommit.getExpectedDataGeneration() != null) {
       // These values are not passed in the request keyArgs, so add them into the auditMap if they are present
       // in the open key entry.
-      auditMap.put(OzoneConsts.REWRITE_GENERATION, String.valueOf(toCommit.getExpectedDataGeneration()));
-      if (existing == null) {
-        throw new OMException("Atomic rewrite is not allowed for a new key", KEY_NOT_FOUND);
-      }
-      if (!toCommit.getExpectedDataGeneration().equals(existing.getUpdateID())) {
-        throw new OMException("Cannot commit as current generation (" + existing.getUpdateID() +
-            ") does not match the expected generation to rewrite (" + toCommit.getExpectedDataGeneration() + ")",
-            KEY_NOT_FOUND);
+      Long expectedGen = toCommit.getExpectedDataGeneration();
+      auditMap.put(OzoneConsts.REWRITE_GENERATION, String.valueOf(expectedGen));
+
+      if (expectedGen == OzoneConsts.EXPECTED_GEN_CREATE_IF_NOT_EXISTS) {
+        if (existing != null) {
+          throw new OMException("Key already exists",
+              OMException.ResultCodes.KEY_ALREADY_EXISTS);
+        }
+      } else {
+        if (existing == null) {
+          throw new OMException("Atomic rewrite is not allowed for a new key", KEY_NOT_FOUND);
+        }
+        if (!toCommit.getExpectedDataGeneration().equals(existing.getUpdateID())) {
+          throw new OMException("Cannot commit as current generation (" + existing.getUpdateID() +
+              ") does not match the expected generation to rewrite (" + toCommit.getExpectedDataGeneration() + ")",
+              KEY_NOT_FOUND);
+        }
       }
     }
   }

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/request/key/OMKeyCreateRequest.java

@@ -35,6 +35,7 @@
 import org.apache.hadoop.hdds.scm.container.common.helpers.ExcludeList;
 import org.apache.hadoop.hdds.utils.UniqueId;
 import org.apache.hadoop.ozone.OmUtils;
+import org.apache.hadoop.ozone.OzoneConsts;
 import org.apache.hadoop.ozone.OzoneManagerVersion;
 import org.apache.hadoop.ozone.audit.OMAction;
 import org.apache.hadoop.ozone.om.OMMetadataManager;
@@ -178,7 +179,7 @@ public OMRequest preExecute(OzoneManager ozoneManager) throws IOException {
 
     KeyArgs.Builder finalNewKeyArgs = newKeyArgs;
     KeyArgs resolvedKeyArgs =
-        captureLatencyNs(perfMetrics.getCreateKeyResolveBucketAndAclCheckLatencyNs(), 
+        captureLatencyNs(perfMetrics.getCreateKeyResolveBucketAndAclCheckLatencyNs(),
             () -> resolveBucketAndCheckKeyAcls(finalNewKeyArgs.build(), ozoneManager,
             IAccessAuthorizer.ACLType.CREATE));
     newCreateKeyRequest =
@@ -358,7 +359,7 @@ public OMClientResponse validateAndUpdateCache(OzoneManager ozoneManager, Execut
       } else {
         perfMetrics.addCreateKeyFailureLatencyNs(createKeyLatency);
       }
-      
+
       if (acquireLock) {
         mergeOmLockDetails(ozoneLockStrategy
             .releaseWriteLock(omMetadataManager, volumeName,
@@ -460,12 +461,22 @@ public static OMRequest blockCreateKeyWithBucketLayoutFromOldClient(
   protected void validateAtomicRewrite(OmKeyInfo dbKeyInfo, KeyArgs keyArgs)
       throws OMException {
     if (keyArgs.hasExpectedDataGeneration()) {
-      // If a key does not exist, or if it exists but the updateID do not match, then fail this request.
-      if (dbKeyInfo == null) {
-        throw new OMException("Key not found during expected rewrite", OMException.ResultCodes.KEY_NOT_FOUND);
-      }
-      if (dbKeyInfo.getUpdateID() != keyArgs.getExpectedDataGeneration()) {
-        throw new OMException("Generation mismatch during expected rewrite", OMException.ResultCodes.KEY_NOT_FOUND);
+      long expectedGen = keyArgs.getExpectedDataGeneration();
+      // If expectedGen is EXPECTED_GEN_CREATE_IF_NOT_EXISTS, it means the key MUST NOT exist (If-None-Match)
+      if (expectedGen == OzoneConsts.EXPECTED_GEN_CREATE_IF_NOT_EXISTS) {
+        if (dbKeyInfo != null) {
+          throw new OMException("Key already exists",
+              OMException.ResultCodes.KEY_ALREADY_EXISTS);
+        }
+      } else {
+        // If a key does not exist, or if it exists but the updateID do not match, then fail this request.
+        if (dbKeyInfo == null) {
+          throw new OMException("Key not found during expected rewrite", OMException.ResultCodes.KEY_NOT_FOUND);
+        }
+        if (dbKeyInfo.getUpdateID() != expectedGen) {
+          throw new OMException("Generation mismatch during expected rewrite",
+              OMException.ResultCodes.KEY_NOT_FOUND);
+        }
       }
     }
   }

hadoop-ozone/ozone-manager/src/test/java/org/apache/hadoop/ozone/om/request/key/TestOMKeyCommitRequest.java

@@ -17,6 +17,7 @@
 
 package org.apache.hadoop.ozone.om.request.key;
 
+import static org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos.Status.KEY_ALREADY_EXISTS;
 import static org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos.Status.KEY_NOT_FOUND;
 import static org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos.Status.OK;
 import static org.assertj.core.api.Assertions.assertThat;
@@ -279,6 +280,76 @@ public void testAtomicRewrite() throws Exception {
     assertEquals(acls, committedKey.getAcls());
   }
 
+  @Test
+  public void testAtomicCreateIfNotExistsCommitKeyAbsent() throws Exception {
+    Table<String, OmKeyInfo> openKeyTable = omMetadataManager.getOpenKeyTable(getBucketLayout());
+    Table<String, OmKeyInfo> closedKeyTable = omMetadataManager.getKeyTable(getBucketLayout());
+
+    OMRequest modifiedOmRequest = doPreExecute(createCommitKeyRequest());
+    OMKeyCommitRequest omKeyCommitRequest = getOmKeyCommitRequest(modifiedOmRequest);
+    KeyArgs keyArgs = modifiedOmRequest.getCommitKeyRequest().getKeyArgs();
+
+    OMRequestTestUtils.addVolumeAndBucketToDB(volumeName, bucketName,
+        omMetadataManager, omKeyCommitRequest.getBucketLayout());
+
+    List<OmKeyLocationInfo> allocatedLocationList =
+        keyArgs.getKeyLocationsList().stream()
+            .map(OmKeyLocationInfo::getFromProtobuf)
+            .collect(Collectors.toList());
+
+    OmKeyInfo.Builder omKeyInfoBuilder = OMRequestTestUtils.createOmKeyInfo(
+        volumeName, bucketName, keyName, replicationConfig,
+        new OmKeyLocationInfoGroup(version, new ArrayList<>()));
+    omKeyInfoBuilder.setExpectedDataGeneration(OzoneConsts.EXPECTED_GEN_CREATE_IF_NOT_EXISTS);
+
+    String openKey = addKeyToOpenKeyTable(allocatedLocationList, omKeyInfoBuilder);
+    assertNotNull(openKeyTable.get(openKey));
+    assertNull(closedKeyTable.get(getOzonePathKey()));
+
+    OMClientResponse omClientResponse =
+        omKeyCommitRequest.validateAndUpdateCache(ozoneManager, 100L);
+    assertEquals(OK, omClientResponse.getOMResponse().getStatus());
+
+    OmKeyInfo committedKey = closedKeyTable.get(getOzonePathKey());
+    assertNotNull(committedKey);
+    assertNull(committedKey.getExpectedDataGeneration());
+  }
+
+  @Test
+  public void testAtomicCreateIfNotExistsCommitKeyAlreadyExists() throws Exception {
+    Table<String, OmKeyInfo> openKeyTable = omMetadataManager.getOpenKeyTable(getBucketLayout());
+    Table<String, OmKeyInfo> closedKeyTable = omMetadataManager.getKeyTable(getBucketLayout());
+
+    OMRequest modifiedOmRequest = doPreExecute(createCommitKeyRequest());
+    OMKeyCommitRequest omKeyCommitRequest = getOmKeyCommitRequest(modifiedOmRequest);
+    KeyArgs keyArgs = modifiedOmRequest.getCommitKeyRequest().getKeyArgs();
+
+    OMRequestTestUtils.addVolumeAndBucketToDB(volumeName, bucketName,
+        omMetadataManager, omKeyCommitRequest.getBucketLayout());
+
+    List<OmKeyLocationInfo> allocatedLocationList =
+        keyArgs.getKeyLocationsList().stream()
+            .map(OmKeyLocationInfo::getFromProtobuf)
+            .collect(Collectors.toList());
+
+    OmKeyInfo.Builder omKeyInfoBuilder = OMRequestTestUtils.createOmKeyInfo(
+        volumeName, bucketName, keyName, replicationConfig,
+        new OmKeyLocationInfoGroup(version, new ArrayList<>()));
+    omKeyInfoBuilder.setExpectedDataGeneration(OzoneConsts.EXPECTED_GEN_CREATE_IF_NOT_EXISTS);
+
+    String openKey = addKeyToOpenKeyTable(allocatedLocationList, omKeyInfoBuilder);
+    assertNotNull(openKeyTable.get(openKey));
+
+    OmKeyInfo existingClosedKey = OMRequestTestUtils.createOmKeyInfo(
+        volumeName, bucketName, keyName, replicationConfig,
+        new OmKeyLocationInfoGroup(version, new ArrayList<>())).build();
+    closedKeyTable.put(getOzonePathKey(), existingClosedKey);
+
+    OMClientResponse omClientResponse =
+        omKeyCommitRequest.validateAndUpdateCache(ozoneManager, 100L);
+    assertEquals(KEY_ALREADY_EXISTS, omClientResponse.getOMResponse().getStatus());
+  }
+
   @Test
   public void testValidateAndUpdateCacheWithUncommittedBlocks()
       throws Exception {
@@ -456,7 +527,7 @@ private Map<String, RepeatedOmKeyInfo> doKeyCommit(boolean isHSync,
         .collect(Collectors.toList());
     String openKey = addKeyToOpenKeyTable(allocatedBlockList);
     String ozoneKey = getOzonePathKey();
-    
+
     OMClientResponse omClientResponse =
         omKeyCommitRequest.validateAndUpdateCache(ozoneManager, 100L);
     assertEquals(OK,