diff --git a/hdfs/CHANGES.HDFS-1623.txt b/hdfs/CHANGES.HDFS-1623.txt
index eeb80edc5a..91d58c04a2 100644
--- a/hdfs/CHANGES.HDFS-1623.txt
+++ b/hdfs/CHANGES.HDFS-1623.txt
@@ -5,3 +5,5 @@ branch is merged.
------------------------------
HDFS-2179. Add fencing framework and mechanisms for NameNode HA. (todd)
+
+HDFS-1974. Introduce active and standy states to the namenode. (suresh)
diff --git a/hdfs/src/java/org/apache/hadoop/hdfs/DFSUtil.java b/hdfs/src/java/org/apache/hadoop/hdfs/DFSUtil.java
index 8ccba1f8ae..5d32c7a05e 100644
--- a/hdfs/src/java/org/apache/hadoop/hdfs/DFSUtil.java
+++ b/hdfs/src/java/org/apache/hadoop/hdfs/DFSUtil.java
@@ -696,4 +696,14 @@ public class DFSUtil {
ClientDatanodeProtocol.versionID, addr, ticket, confWithNoIpcIdle,
NetUtils.getDefaultSocketFactory(conf), socketTimeout);
}
+
+ /**
+ * Returns true if HA for namenode is configured.
+ * @param conf Configuration
+ * @return true if HA is configured in the configuration; else false.
+ */
+ public static boolean isHAEnabled(Configuration conf) {
+ // TODO:HA configuration changes pending
+ return false;
+ }
}
diff --git a/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/BackupNode.java b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/BackupNode.java
index ad575b9e27..25667b65a2 100644
--- a/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/BackupNode.java
+++ b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/BackupNode.java
@@ -188,34 +188,6 @@ public class BackupNode extends NameNode implements JournalProtocol {
}
}
- /////////////////////////////////////////////////////
- // NamenodeProtocol implementation for backup node.
- /////////////////////////////////////////////////////
- @Override // NamenodeProtocol
- public BlocksWithLocations getBlocks(DatanodeInfo datanode, long size)
- throws IOException {
- throw new UnsupportedActionException("getBlocks");
- }
-
- // Only active name-node can register other nodes.
- @Override // NamenodeProtocol
- public NamenodeRegistration register(NamenodeRegistration registration
- ) throws IOException {
- throw new UnsupportedActionException("register");
- }
-
- @Override // NamenodeProtocol
- public NamenodeCommand startCheckpoint(NamenodeRegistration registration)
- throws IOException {
- throw new UnsupportedActionException("startCheckpoint");
- }
-
- @Override // NamenodeProtocol
- public void endCheckpoint(NamenodeRegistration registration,
- CheckpointSignature sig) throws IOException {
- throw new UnsupportedActionException("endCheckpoint");
- }
-
/////////////////////////////////////////////////////
// BackupNodeProtocol implementation for backup node.
/////////////////////////////////////////////////////
@@ -224,6 +196,7 @@ public class BackupNode extends NameNode implements JournalProtocol {
public void journal(NamenodeRegistration nnReg,
long firstTxId, int numTxns,
byte[] records) throws IOException {
+ checkOperation(OperationCategory.JOURNAL);
verifyRequest(nnReg);
if(!nnRpcAddress.equals(nnReg.getAddress()))
throw new IOException("Journal request from unexpected name-node: "
@@ -234,6 +207,7 @@ public class BackupNode extends NameNode implements JournalProtocol {
@Override
public void startLogSegment(NamenodeRegistration registration, long txid)
throws IOException {
+ checkOperation(OperationCategory.JOURNAL);
verifyRequest(registration);
getBNImage().namenodeStartedLogSegment(txid);
@@ -369,4 +343,14 @@ public class BackupNode extends NameNode implements JournalProtocol {
String getClusterId() {
return clusterId;
}
+
+ @Override // NameNode
+ protected void checkOperation(OperationCategory op)
+ throws UnsupportedActionException {
+ if (OperationCategory.JOURNAL != op) {
+ String msg = "Operation category " + op
+ + " is not supported at the BackupNode";
+ throw new UnsupportedActionException(msg);
+ }
+ }
}
diff --git a/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
index 3c2f40bb65..4b227225d4 100644
--- a/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
+++ b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
@@ -31,6 +31,8 @@ import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.ha.HealthCheckFailedException;
+import org.apache.hadoop.ha.ServiceFailedException;
import org.apache.hadoop.fs.CommonConfigurationKeys;
import org.apache.hadoop.fs.ContentSummary;
import org.apache.hadoop.fs.CreateFlag;
@@ -67,11 +69,15 @@ import org.apache.hadoop.hdfs.server.common.HdfsConstants.NamenodeRole;
import org.apache.hadoop.hdfs.server.common.HdfsConstants.StartupOption;
import org.apache.hadoop.hdfs.server.common.IncorrectVersionException;
import org.apache.hadoop.hdfs.server.common.UpgradeStatusReport;
+import org.apache.hadoop.hdfs.server.namenode.ha.ActiveState;
+import org.apache.hadoop.hdfs.server.namenode.ha.HAState;
+import org.apache.hadoop.hdfs.server.namenode.ha.StandbyState;
import org.apache.hadoop.hdfs.server.namenode.metrics.NameNodeMetrics;
import org.apache.hadoop.hdfs.server.protocol.BlocksWithLocations;
import org.apache.hadoop.hdfs.server.protocol.DatanodeCommand;
import org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol;
import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
+import org.apache.hadoop.hdfs.server.protocol.JournalProtocol;
import org.apache.hadoop.hdfs.server.protocol.NamenodeCommand;
import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocols;
@@ -145,6 +151,20 @@ public class NameNode implements NamenodeProtocols, FSConstants {
HdfsConfiguration.init();
}
+ /**
+ * Categories of operations supported by the namenode.
+ */
+ public static enum OperationCategory {
+ /** Read operation that does not change the namespace state */
+ READ,
+ /** Write operation that changes the namespace state */
+ WRITE,
+ /** Operations related to checkpointing */
+ CHECKPOINT,
+ /** Operations related to {@link JournalProtocol} */
+ JOURNAL
+ }
+
/**
* HDFS federation configuration can have two types of parameters:
*
@@ -204,9 +224,15 @@ public class NameNode implements NamenodeProtocols, FSConstants {
public static final Log LOG = LogFactory.getLog(NameNode.class.getName());
public static final Log stateChangeLog = LogFactory.getLog("org.apache.hadoop.hdfs.StateChange");
+ public static final HAState ACTIVE_STATE = new ActiveState();
+ public static final HAState STANDBY_STATE = new StandbyState();
protected FSNamesystem namesystem;
protected NamenodeRole role;
+ private HAState state;
+ private final boolean haEnabled;
+
+
/** RPC server. Package-protected for use in tests. */
Server server;
/** RPC server for HDFS Services communication.
@@ -402,6 +428,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
* @param conf the configuration
*/
protected void initialize(Configuration conf) throws IOException {
+ initializeGenericKeys(conf);
InetSocketAddress socAddr = getRpcServerAddress(conf);
UserGroupInformation.setConfiguration(conf);
loginAsNameNodeUser(conf);
@@ -450,10 +477,6 @@ public class NameNode implements NamenodeProtocols, FSConstants {
}
activate(conf);
- LOG.info(getRole() + " up at: " + rpcAddress);
- if (serviceRPCAddress != null) {
- LOG.info(getRole() + " service server is up at: " + serviceRPCAddress);
- }
}
/**
@@ -503,6 +526,10 @@ public class NameNode implements NamenodeProtocols, FSConstants {
LOG.warn("ServicePlugin " + p + " could not be started", t);
}
}
+ LOG.info(getRole() + " up at: " + rpcAddress);
+ if (serviceRPCAddress != null) {
+ LOG.info(getRole() + " service server is up at: " + serviceRPCAddress);
+ }
}
private void startTrashEmptier(Configuration conf) throws IOException {
@@ -556,8 +583,9 @@ public class NameNode implements NamenodeProtocols, FSConstants {
protected NameNode(Configuration conf, NamenodeRole role)
throws IOException {
this.role = role;
+ this.haEnabled = DFSUtil.isHAEnabled(conf);
+ this.state = !haEnabled ? ACTIVE_STATE : STANDBY_STATE;
try {
- initializeGenericKeys(conf);
initialize(conf);
} catch (IOException e) {
this.stop();
@@ -638,6 +666,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
public void errorReport(NamenodeRegistration registration,
int errorCode,
String msg) throws IOException {
+ checkOperation(OperationCategory.WRITE);
verifyRequest(registration);
LOG.info("Error report from " + registration + ": " + msg);
if(errorCode == FATAL)
@@ -665,27 +694,28 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // NamenodeProtocol
public void endCheckpoint(NamenodeRegistration registration,
CheckpointSignature sig) throws IOException {
- verifyRequest(registration);
- if(!isRole(NamenodeRole.NAMENODE))
- throw new IOException("Only an ACTIVE node can invoke endCheckpoint.");
+ checkOperation(OperationCategory.CHECKPOINT);
namesystem.endCheckpoint(registration, sig);
}
@Override // ClientProtocol
public Token getDelegationToken(Text renewer)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
return namesystem.getDelegationToken(renewer);
}
@Override // ClientProtocol
public long renewDelegationToken(Token token)
throws InvalidToken, IOException {
+ checkOperation(OperationCategory.WRITE);
return namesystem.renewDelegationToken(token);
}
@Override // ClientProtocol
public void cancelDelegationToken(Token token)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.cancelDelegationToken(token);
}
@@ -694,6 +724,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
long offset,
long length)
throws IOException {
+ checkOperation(OperationCategory.READ);
metrics.incrGetBlockLocations();
return namesystem.getBlockLocations(getClientMachine(),
src, offset, length);
@@ -712,6 +743,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
boolean createParent,
short replication,
long blockSize) throws IOException {
+ checkOperation(OperationCategory.WRITE);
String clientMachine = getClientMachine();
if (stateChangeLog.isDebugEnabled()) {
stateChangeLog.debug("*DIR* NameNode.create: file "
@@ -732,6 +764,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public LocatedBlock append(String src, String clientName)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
String clientMachine = getClientMachine();
if (stateChangeLog.isDebugEnabled()) {
stateChangeLog.debug("*DIR* NameNode.append: file "
@@ -744,6 +777,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public boolean recoverLease(String src, String clientName) throws IOException {
+ checkOperation(OperationCategory.WRITE);
String clientMachine = getClientMachine();
return namesystem.recoverLease(src, clientName, clientMachine);
}
@@ -751,18 +785,21 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public boolean setReplication(String src, short replication)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
return namesystem.setReplication(src, replication);
}
@Override // ClientProtocol
public void setPermission(String src, FsPermission permissions)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.setPermission(src, permissions);
}
@Override // ClientProtocol
public void setOwner(String src, String username, String groupname)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.setOwner(src, username, groupname);
}
@@ -772,6 +809,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
ExtendedBlock previous,
DatanodeInfo[] excludedNodes)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
if(stateChangeLog.isDebugEnabled()) {
stateChangeLog.debug("*BLOCK* NameNode.addBlock: file "
+src+" for "+clientName);
@@ -795,6 +833,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
final DatanodeInfo[] existings, final DatanodeInfo[] excludes,
final int numAdditionalNodes, final String clientName
) throws IOException {
+ checkOperation(OperationCategory.WRITE);
if (LOG.isDebugEnabled()) {
LOG.debug("getAdditionalDatanode: src=" + src
+ ", blk=" + blk
@@ -820,8 +859,10 @@ public class NameNode implements NamenodeProtocols, FSConstants {
/**
* The client needs to give up on the block.
*/
+ @Override // ClientProtocol
public void abandonBlock(ExtendedBlock b, String src, String holder)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
if(stateChangeLog.isDebugEnabled()) {
stateChangeLog.debug("*BLOCK* NameNode.abandonBlock: "
+b+" of file "+src);
@@ -834,6 +875,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public boolean complete(String src, String clientName, ExtendedBlock last)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
if(stateChangeLog.isDebugEnabled()) {
stateChangeLog.debug("*DIR* NameNode.complete: "
+ src + " for " + clientName);
@@ -847,8 +889,9 @@ public class NameNode implements NamenodeProtocols, FSConstants {
* mark the block as corrupt. In the future we might
* check the blocks are actually corrupt.
*/
- @Override
+ @Override // ClientProtocol, DatanodeProtocol
public void reportBadBlocks(LocatedBlock[] blocks) throws IOException {
+ checkOperation(OperationCategory.WRITE);
stateChangeLog.info("*DIR* NameNode.reportBadBlocks");
for (int i = 0; i < blocks.length; i++) {
ExtendedBlock blk = blocks[i].getBlock();
@@ -863,6 +906,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public LocatedBlock updateBlockForPipeline(ExtendedBlock block, String clientName)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
return namesystem.updateBlockForPipeline(block, clientName);
}
@@ -871,6 +915,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
public void updatePipeline(String clientName, ExtendedBlock oldBlock,
ExtendedBlock newBlock, DatanodeID[] newNodes)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.updatePipeline(clientName, oldBlock, newBlock, newNodes);
}
@@ -879,6 +924,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
long newgenerationstamp, long newlength,
boolean closeFile, boolean deleteblock, DatanodeID[] newtargets)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.commitBlockSynchronization(block,
newgenerationstamp, newlength, closeFile, deleteblock, newtargets);
}
@@ -886,12 +932,14 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public long getPreferredBlockSize(String filename)
throws IOException {
+ checkOperation(OperationCategory.READ);
return namesystem.getPreferredBlockSize(filename);
}
@Deprecated
@Override // ClientProtocol
public boolean rename(String src, String dst) throws IOException {
+ checkOperation(OperationCategory.WRITE);
if(stateChangeLog.isDebugEnabled()) {
stateChangeLog.debug("*DIR* NameNode.rename: " + src + " to " + dst);
}
@@ -908,12 +956,14 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public void concat(String trg, String[] src) throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.concat(trg, src);
}
@Override // ClientProtocol
public void rename(String src, String dst, Options.Rename... options)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
if(stateChangeLog.isDebugEnabled()) {
stateChangeLog.debug("*DIR* NameNode.rename: " + src + " to " + dst);
}
@@ -928,11 +978,13 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Deprecated
@Override // ClientProtocol
public boolean delete(String src) throws IOException {
+ checkOperation(OperationCategory.WRITE);
return delete(src, true);
}
@Override // ClientProtocol
public boolean delete(String src, boolean recursive) throws IOException {
+ checkOperation(OperationCategory.WRITE);
if (stateChangeLog.isDebugEnabled()) {
stateChangeLog.debug("*DIR* Namenode.delete: src=" + src
+ ", recursive=" + recursive);
@@ -957,6 +1009,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public boolean mkdirs(String src, FsPermission masked, boolean createParent)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
if(stateChangeLog.isDebugEnabled()) {
stateChangeLog.debug("*DIR* NameNode.mkdirs: " + src);
}
@@ -971,13 +1024,14 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public void renewLease(String clientName) throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.renewLease(clientName);
}
@Override // ClientProtocol
public DirectoryListing getListing(String src, byte[] startAfter,
- boolean needLocation)
- throws IOException {
+ boolean needLocation) throws IOException {
+ checkOperation(OperationCategory.READ);
DirectoryListing files = namesystem.getListing(
src, startAfter, needLocation);
if (files != null) {
@@ -989,12 +1043,14 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public HdfsFileStatus getFileInfo(String src) throws IOException {
+ checkOperation(OperationCategory.READ);
metrics.incrFileInfoOps();
return namesystem.getFileInfo(src, true);
}
@Override // ClientProtocol
public HdfsFileStatus getFileLinkInfo(String src) throws IOException {
+ checkOperation(OperationCategory.READ);
metrics.incrFileInfoOps();
return namesystem.getFileInfo(src, false);
}
@@ -1007,6 +1063,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public DatanodeInfo[] getDatanodeReport(DatanodeReportType type)
throws IOException {
+ checkOperation(OperationCategory.READ);
DatanodeInfo results[] = namesystem.datanodeReport(type);
if (results == null ) {
throw new IOException("Cannot find datanode report");
@@ -1016,6 +1073,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public boolean setSafeMode(SafeModeAction action) throws IOException {
+ // TODO:HA decide on OperationCategory for this
return namesystem.setSafeMode(action);
}
@@ -1029,54 +1087,64 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public boolean restoreFailedStorage(String arg)
throws AccessControlException {
+ // TODO:HA decide on OperationCategory for this
return namesystem.restoreFailedStorage(arg);
}
@Override // ClientProtocol
public void saveNamespace() throws IOException {
+ // TODO:HA decide on OperationCategory for this
namesystem.saveNamespace();
}
@Override // ClientProtocol
public void refreshNodes() throws IOException {
+ // TODO:HA decide on OperationCategory for this
namesystem.refreshNodes(new HdfsConfiguration());
}
@Override // NamenodeProtocol
public long getTransactionID() {
+ // TODO:HA decide on OperationCategory for this
return namesystem.getTransactionID();
}
@Override // NamenodeProtocol
public CheckpointSignature rollEditLog() throws IOException {
+ // TODO:HA decide on OperationCategory for this
return namesystem.rollEditLog();
}
- @Override
+ @Override // NamenodeProtocol
public RemoteEditLogManifest getEditLogManifest(long sinceTxId)
throws IOException {
+ // TODO:HA decide on OperationCategory for this
return namesystem.getEditLogManifest(sinceTxId);
}
@Override // ClientProtocol
public void finalizeUpgrade() throws IOException {
+ // TODO:HA decide on OperationCategory for this
namesystem.finalizeUpgrade();
}
@Override // ClientProtocol
public UpgradeStatusReport distributedUpgradeProgress(UpgradeAction action)
throws IOException {
+ // TODO:HA decide on OperationCategory for this
return namesystem.distributedUpgradeProgress(action);
}
@Override // ClientProtocol
public void metaSave(String filename) throws IOException {
+ // TODO:HA decide on OperationCategory for this
namesystem.metaSave(filename);
}
@Override // ClientProtocol
public CorruptFileBlocks listCorruptFileBlocks(String path, String cookie)
throws IOException {
+ checkOperation(OperationCategory.READ);
Collection fbs =
namesystem.listCorruptFileBlocks(path, cookie);
@@ -1096,35 +1164,42 @@ public class NameNode implements NamenodeProtocols, FSConstants {
* @param bandwidth Blanacer bandwidth in bytes per second for all datanodes.
* @throws IOException
*/
+ @Override // ClientProtocol
public void setBalancerBandwidth(long bandwidth) throws IOException {
+ // TODO:HA decide on OperationCategory for this
namesystem.setBalancerBandwidth(bandwidth);
}
@Override // ClientProtocol
public ContentSummary getContentSummary(String path) throws IOException {
+ checkOperation(OperationCategory.READ);
return namesystem.getContentSummary(path);
}
@Override // ClientProtocol
public void setQuota(String path, long namespaceQuota, long diskspaceQuota)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.setQuota(path, namespaceQuota, diskspaceQuota);
}
@Override // ClientProtocol
public void fsync(String src, String clientName) throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.fsync(src, clientName);
}
@Override // ClientProtocol
public void setTimes(String src, long mtime, long atime)
throws IOException {
+ checkOperation(OperationCategory.WRITE);
namesystem.setTimes(src, mtime, atime);
}
@Override // ClientProtocol
public void createSymlink(String target, String link, FsPermission dirPerms,
boolean createParent) throws IOException {
+ checkOperation(OperationCategory.WRITE);
metrics.incrCreateSymlinkOps();
/* We enforce the MAX_PATH_LENGTH limit even though a symlink target
* URI may refer to a non-HDFS file system.
@@ -1144,6 +1219,7 @@ public class NameNode implements NamenodeProtocols, FSConstants {
@Override // ClientProtocol
public String getLinkTarget(String path) throws IOException {
+ checkOperation(OperationCategory.READ);
metrics.incrGetLinkTargetOps();
/* Resolves the first symlink in the given path, returning a
* new path consisting of the target of the symlink and any
@@ -1591,4 +1667,43 @@ public class NameNode implements NamenodeProtocols, FSConstants {
}
return clientMachine;
}
+
+ @Override // HAServiceProtocol
+ public synchronized void monitorHealth() throws HealthCheckFailedException {
+ if (!haEnabled) {
+ return; // no-op, if HA is not eanbled
+ }
+ // TODO:HA implement health check
+ return;
+ }
+
+ @Override // HAServiceProtocol
+ public synchronized void transitionToActive() throws ServiceFailedException {
+ if (!haEnabled) {
+ throw new ServiceFailedException("HA for namenode is not enabled");
+ }
+ state.setState(this, ACTIVE_STATE);
+ }
+
+ @Override // HAServiceProtocol
+ public synchronized void transitionToStandby() throws ServiceFailedException {
+ if (!haEnabled) {
+ throw new ServiceFailedException("HA for namenode is not enabled");
+ }
+ state.setState(this, STANDBY_STATE);
+ }
+
+ /** Check if an operation of given category is allowed */
+ protected synchronized void checkOperation(final OperationCategory op)
+ throws UnsupportedActionException {
+ state.checkOperation(this, op);
+ }
+
+ public synchronized HAState getState() {
+ return state;
+ }
+
+ public synchronized void setState(final HAState s) {
+ state = s;
+ }
}
diff --git a/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/UnsupportedActionException.java b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/UnsupportedActionException.java
index 9ac17fc57c..ca7e1d7787 100644
--- a/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/UnsupportedActionException.java
+++ b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/UnsupportedActionException.java
@@ -32,8 +32,7 @@ public class UnsupportedActionException extends IOException {
/** for java.io.Serializable */
private static final long serialVersionUID = 1L;
- public UnsupportedActionException(String action) {
- super("Action " + action + "() is not supported.");
+ public UnsupportedActionException(String msg) {
+ super(msg);
}
-
}
diff --git a/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/ha/ActiveState.java b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/ha/ActiveState.java
new file mode 100644
index 0000000000..1cf24f7f23
--- /dev/null
+++ b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/ha/ActiveState.java
@@ -0,0 +1,59 @@
+/**
+ * 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.namenode.ha;
+
+import org.apache.hadoop.ha.ServiceFailedException;
+import org.apache.hadoop.hdfs.server.namenode.NameNode;
+import org.apache.hadoop.hdfs.server.namenode.NameNode.OperationCategory;
+import org.apache.hadoop.hdfs.server.namenode.UnsupportedActionException;
+
+/**
+ * Active state of the namenode. In this state, namenode provides the namenode
+ * service and handles operations of type {@link OperationCategory#WRITE} and
+ * {@link OperationCategory#READ}.
+ */
+public class ActiveState extends HAState {
+ public ActiveState() {
+ super("active");
+ }
+
+ @Override
+ public void checkOperation(NameNode nn, OperationCategory op)
+ throws UnsupportedActionException {
+ return; // Other than journal all operations are allowed in active state
+ }
+
+ @Override
+ public void setState(NameNode nn, HAState s) throws ServiceFailedException {
+ if (s == NameNode.STANDBY_STATE) {
+ setStateInternal(nn, s);
+ return;
+ }
+ super.setState(nn, s);
+ }
+
+ @Override
+ protected void enterState(NameNode nn) throws ServiceFailedException {
+ // TODO:HA
+ }
+
+ @Override
+ protected void exitState(NameNode nn) throws ServiceFailedException {
+ // TODO:HA
+ }
+}
diff --git a/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/ha/HAState.java b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/ha/HAState.java
new file mode 100644
index 0000000000..1828f9c83d
--- /dev/null
+++ b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/ha/HAState.java
@@ -0,0 +1,104 @@
+/**
+ * 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.namenode.ha;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.ha.ServiceFailedException;
+import org.apache.hadoop.hdfs.server.namenode.NameNode;
+import org.apache.hadoop.hdfs.server.namenode.NameNode.OperationCategory;
+import org.apache.hadoop.hdfs.server.namenode.UnsupportedActionException;
+
+/**
+ * Namenode base state to implement state machine pattern.
+ */
+@InterfaceAudience.Private
+abstract public class HAState {
+ protected final String name;
+
+ /**
+ * Constructor
+ * @param name Name of the state.
+ */
+ public HAState(String name) {
+ this.name = name;
+ }
+
+ /**
+ * Internal method to transition the state of a given namenode to a new state.
+ * @param nn Namenode
+ * @param s new state
+ * @throws ServiceFailedException on failure to transition to new state.
+ */
+ protected final void setStateInternal(final NameNode nn, final HAState s)
+ throws ServiceFailedException {
+ exitState(nn);
+ nn.setState(s);
+ s.enterState(nn);
+ }
+
+ /**
+ * Method to be overridden by subclasses to perform steps necessary for
+ * entering a state.
+ * @param nn Namenode
+ * @throws ServiceFailedException on failure to enter the state.
+ */
+ protected abstract void enterState(final NameNode nn)
+ throws ServiceFailedException;
+
+ /**
+ * Method to be overridden by subclasses to perform steps necessary for
+ * exiting a state.
+ * @param nn Namenode
+ * @throws ServiceFailedException on failure to enter the state.
+ */
+ protected abstract void exitState(final NameNode nn)
+ throws ServiceFailedException;
+
+ /**
+ * Move from the existing state to a new state
+ * @param nn Namenode
+ * @param s new state
+ * @throws ServiceFailedException on failure to transition to new state.
+ */
+ public void setState(NameNode nn, HAState s) throws ServiceFailedException {
+ if (this == s) { // Aleady in the new state
+ return;
+ }
+ throw new ServiceFailedException("Transtion from state " + this + " to "
+ + s + " is not allowed.");
+ }
+
+ /**
+ * Check if an operation is supported in a given state.
+ * @param nn Namenode
+ * @param op Type of the operation.
+ * @throws UnsupportedActionException if a given type of operation is not
+ * supported in this state.
+ */
+ public void checkOperation(final NameNode nn, final OperationCategory op)
+ throws UnsupportedActionException {
+ String msg = "Operation category " + op + " is not supported in state "
+ + nn.getState();
+ throw new UnsupportedActionException(msg);
+ }
+
+ @Override
+ public String toString() {
+ return super.toString();
+ }
+}
\ No newline at end of file
diff --git a/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/ha/StandbyState.java b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/ha/StandbyState.java
new file mode 100644
index 0000000000..b63866dc71
--- /dev/null
+++ b/hdfs/src/java/org/apache/hadoop/hdfs/server/namenode/ha/StandbyState.java
@@ -0,0 +1,58 @@
+/**
+ * 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.namenode.ha;
+
+import org.apache.hadoop.ha.ServiceFailedException;
+import org.apache.hadoop.hdfs.server.namenode.NameNode;
+
+/**
+ * Namenode standby state. In this state the namenode acts as warm standby and
+ * keeps the following updated:
+ *
+ * - Namespace by getting the edits.
+ * - Block location information by receiving block reports and blocks
+ * received from the datanodes.
+ *
+ *
+ * It does not handle read/write/checkpoint operations.
+ */
+public class StandbyState extends HAState {
+ public StandbyState() {
+ super("standby");
+ }
+
+ @Override
+ public void setState(NameNode nn, HAState s) throws ServiceFailedException {
+ if (s == NameNode.ACTIVE_STATE) {
+ setStateInternal(nn, s);
+ return;
+ }
+ super.setState(nn, s);
+ }
+
+ @Override
+ protected void enterState(NameNode nn) throws ServiceFailedException {
+ // TODO:HA
+ }
+
+ @Override
+ protected void exitState(NameNode nn) throws ServiceFailedException {
+ // TODO:HA
+ }
+}
+
diff --git a/hdfs/src/java/org/apache/hadoop/hdfs/server/protocol/NamenodeProtocols.java b/hdfs/src/java/org/apache/hadoop/hdfs/server/protocol/NamenodeProtocols.java
index 4de386f368..e05b8fef28 100644
--- a/hdfs/src/java/org/apache/hadoop/hdfs/server/protocol/NamenodeProtocols.java
+++ b/hdfs/src/java/org/apache/hadoop/hdfs/server/protocol/NamenodeProtocols.java
@@ -19,6 +19,7 @@
package org.apache.hadoop.hdfs.server.protocol;
import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.ha.HAServiceProtocol;
import org.apache.hadoop.hdfs.protocol.ClientProtocol;
import org.apache.hadoop.security.authorize.RefreshAuthorizationPolicyProtocol;
import org.apache.hadoop.security.RefreshUserMappingsProtocol;
@@ -32,5 +33,6 @@ public interface NamenodeProtocols
NamenodeProtocol,
RefreshAuthorizationPolicyProtocol,
RefreshUserMappingsProtocol,
- GetUserMappingsProtocol {
+ GetUserMappingsProtocol,
+ HAServiceProtocol {
}