diff --git a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java index beed4eb3b77..9146057da9b 100644 --- a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java +++ b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/client/HdfsClientConfigKeys.java @@ -43,7 +43,8 @@ public interface HdfsClientConfigKeys { String DFS_NAMENODE_HTTP_PORT_KEY = "dfs.http.port"; String DFS_NAMENODE_HTTPS_PORT_KEY = "dfs.https.port"; int DFS_NAMENODE_RPC_PORT_DEFAULT = 8020; - String DFS_NAMENODE_KERBEROS_PRINCIPAL_KEY = "dfs.namenode.kerberos.principal"; + String DFS_NAMENODE_KERBEROS_PRINCIPAL_KEY = + "dfs.namenode.kerberos.principal"; /** dfs.client.retry configuration properties */ interface Retry { diff --git a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java index aa94b5bd46b..b70d4dc5684 100644 --- a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java +++ b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/ClientProtocol.java @@ -77,32 +77,33 @@ public interface ClientProtocol { /** * Until version 69, this class ClientProtocol served as both - * the client interface to the NN AND the RPC protocol used to + * the client interface to the NN AND the RPC protocol used to * communicate with the NN. - * - * This class is used by both the DFSClient and the + * + * This class is used by both the DFSClient and the * NN server side to insulate from the protocol serialization. - * - * If you are adding/changing this interface then you need to + * + * If you are adding/changing this interface then you need to * change both this class and ALSO related protocol buffer * wire protocol definition in ClientNamenodeProtocol.proto. - * - * For more details on protocol buffer wire protocol, please see + * + * For more details on protocol buffer wire protocol, please see * .../org/apache/hadoop/hdfs/protocolPB/overview.html - * + * * The log of historical changes can be retrieved from the svn). * 69: Eliminate overloaded method names. - * + * * 69L is the last version id when this class was used for protocols - * serialization. DO not update this version any further. + * serialization. DO not update this version any further. */ - public static final long versionID = 69L; - + long versionID = 69L; + /////////////////////////////////////// // File contents /////////////////////////////////////// /** - * Get locations of the blocks of the specified file within the specified range. + * Get locations of the blocks of the specified file + * within the specified range. * DataNode locations for each block are sorted by * the proximity to the client. *

@@ -111,9 +112,9 @@ public interface ClientProtocol { * DataNode locations for each block are sorted by * the distance to the client's address. *

- * The client will then have to contact + * The client will then have to contact * one of the indicated DataNodes to obtain the actual data. - * + * * @param src file name * @param offset range start offset * @param length range length @@ -126,11 +127,8 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public LocatedBlocks getBlockLocations(String src, - long offset, - long length) - throws AccessControlException, FileNotFoundException, - UnresolvedLinkException, IOException; + LocatedBlocks getBlockLocations(String src, long offset, long length) + throws IOException; /** * Get server default values for a number of configuration params. @@ -138,7 +136,7 @@ public interface ClientProtocol { * @throws IOException */ @Idempotent - public FsServerDefaults getServerDefaults() throws IOException; + FsServerDefaults getServerDefaults() throws IOException; /** * Create a new file entry in the namespace. @@ -148,36 +146,36 @@ public interface ClientProtocol { * The name-node does not have a notion of "current" directory for a client. *

* Once created, the file is visible and available for read to other clients. - * Although, other clients cannot {@link #delete(String, boolean)}, re-create or - * {@link #rename(String, String)} it until the file is completed + * Although, other clients cannot {@link #delete(String, boolean)}, re-create + * or {@link #rename(String, String)} it until the file is completed * or explicitly as a result of lease expiration. *

* Blocks have a maximum size. Clients that intend to create - * multi-block files must also use + * multi-block files must also use * {@link #addBlock} * * @param src path of the file being created. * @param masked masked permission. * @param clientName name of the current client. - * @param flag indicates whether the file should be + * @param flag indicates whether the file should be * overwritten if it already exists or create if it does not exist or append. * @param createParent create missing parent directory if true * @param replication block replication factor. * @param blockSize maximum block size. * @param supportedVersions CryptoProtocolVersions supported by the client - * + * * @return the status of the created file, it could be null if the server * doesn't support returning the file status * @throws AccessControlException If access is denied * @throws AlreadyBeingCreatedException if the path does not exist. - * @throws DSQuotaExceededException If file creation violates disk space + * @throws DSQuotaExceededException If file creation violates disk space * quota restriction * @throws FileAlreadyExistsException If file src already exists * @throws FileNotFoundException If parent of src does not exist * and createParent is false * @throws ParentNotDirectoryException If parent of src is not a * directory. - * @throws NSQuotaExceededException If file creation violates name space + * @throws NSQuotaExceededException If file creation violates name space * quota restriction * @throws SafeModeException create not allowed in safemode * @throws UnresolvedLinkException If src contains a symlink @@ -190,33 +188,29 @@ public interface ClientProtocol { * Note that create with {@link CreateFlag#OVERWRITE} is idempotent. */ @AtMostOnce - public HdfsFileStatus create(String src, FsPermission masked, + HdfsFileStatus create(String src, FsPermission masked, String clientName, EnumSetWritable flag, - boolean createParent, short replication, long blockSize, + boolean createParent, short replication, long blockSize, CryptoProtocolVersion[] supportedVersions) - throws AccessControlException, AlreadyBeingCreatedException, - DSQuotaExceededException, FileAlreadyExistsException, - FileNotFoundException, NSQuotaExceededException, - ParentNotDirectoryException, SafeModeException, UnresolvedLinkException, - SnapshotAccessControlException, IOException; + throws IOException; /** - * Append to the end of the file. + * Append to the end of the file. * @param src path of the file being created. * @param clientName name of the current client. * @param flag indicates whether the data is appended to a new block. * @return wrapper with information about the last partial block and file * status if any - * @throws AccessControlException if permission to append file is - * denied by the system. As usually on the client side the exception will + * @throws AccessControlException if permission to append file is + * denied by the system. As usually on the client side the exception will * be wrapped into {@link org.apache.hadoop.ipc.RemoteException}. * Allows appending to an existing file if the server is * configured with the parameter dfs.support.append set to true, otherwise * throws an IOException. - * + * * @throws AccessControlException If permission to append to file is denied * @throws FileNotFoundException If file src is not found - * @throws DSQuotaExceededException If append violates disk space quota + * @throws DSQuotaExceededException If append violates disk space quota * restriction * @throws SafeModeException append not allowed in safemode * @throws UnresolvedLinkException If src contains a symlink @@ -227,27 +221,25 @@ public interface ClientProtocol { * @throws UnsupportedOperationException if append is not supported */ @AtMostOnce - public LastBlockWithStatus append(String src, String clientName, - EnumSetWritable flag) throws AccessControlException, - DSQuotaExceededException, FileNotFoundException, SafeModeException, - UnresolvedLinkException, SnapshotAccessControlException, IOException; + LastBlockWithStatus append(String src, String clientName, + EnumSetWritable flag) throws IOException; /** * Set replication for an existing file. *

* The NameNode sets replication to the new value and returns. - * The actual block replication is not expected to be performed during - * this method call. The blocks will be populated or removed in the + * The actual block replication is not expected to be performed during + * this method call. The blocks will be populated or removed in the * background as the result of the routine block maintenance procedures. - * + * * @param src file name * @param replication new replication - * + * * @return true if successful; * false if file does not exist or is a directory * * @throws AccessControlException If access is denied - * @throws DSQuotaExceededException If replication violates disk space + * @throws DSQuotaExceededException If replication violates disk space * quota restriction * @throws FileNotFoundException If file src is not found * @throws SafeModeException not allowed in safemode @@ -256,21 +248,19 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public boolean setReplication(String src, short replication) - throws AccessControlException, DSQuotaExceededException, - FileNotFoundException, SafeModeException, UnresolvedLinkException, - SnapshotAccessControlException, IOException; + boolean setReplication(String src, short replication) + throws IOException; /** * Get all the available block storage policies. * @return All the in-use block storage policies currently. */ @Idempotent - public BlockStoragePolicy[] getStoragePolicies() throws IOException; + BlockStoragePolicy[] getStoragePolicies() throws IOException; /** - * Set the storage policy for a file/directory - * @param src Path of an existing file/directory. + * Set the storage policy for a file/directory. + * @param src Path of an existing file/directory. * @param policyName The name of the storage policy * @throws SnapshotAccessControlException If access is denied * @throws UnresolvedLinkException if src contains a symlink @@ -278,13 +268,12 @@ public interface ClientProtocol { * @throws QuotaExceededException If changes violate the quota restriction */ @Idempotent - public void setStoragePolicy(String src, String policyName) - throws SnapshotAccessControlException, UnresolvedLinkException, - FileNotFoundException, QuotaExceededException, IOException; + void setStoragePolicy(String src, String policyName) + throws IOException; /** * Set permissions for an existing file/directory. - * + * * @throws AccessControlException If access is denied * @throws FileNotFoundException If file src is not found * @throws SafeModeException not allowed in safemode @@ -293,9 +282,8 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public void setPermission(String src, FsPermission permission) - throws AccessControlException, FileNotFoundException, SafeModeException, - UnresolvedLinkException, SnapshotAccessControlException, IOException; + void setPermission(String src, FsPermission permission) + throws IOException; /** * Set Owner of a path (i.e. a file or a directory). @@ -312,16 +300,15 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public void setOwner(String src, String username, String groupname) - throws AccessControlException, FileNotFoundException, SafeModeException, - UnresolvedLinkException, SnapshotAccessControlException, IOException; + void setOwner(String src, String username, String groupname) + throws IOException; /** * The client can give up on a block by calling abandonBlock(). - * The client can then either obtain a new block, or complete or abandon the + * The client can then either obtain a new block, or complete or abandon the * file. * Any partial writes to the block will be discarded. - * + * * @param b Block to abandon * @param fileId The id of the file where the block resides. Older clients * will pass GRANDFATHER_INODE_ID here. @@ -334,19 +321,18 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public void abandonBlock(ExtendedBlock b, long fileId, + void abandonBlock(ExtendedBlock b, long fileId, String src, String holder) - throws AccessControlException, FileNotFoundException, - UnresolvedLinkException, IOException; + throws IOException; /** - * A client that wants to write an additional block to the + * A client that wants to write an additional block to the * indicated filename (which must currently be open for writing) - * should call addBlock(). + * should call addBlock(). * * addBlock() allocates a new block and datanodes the block data * should be replicated to. - * + * * addBlock() also commits the previous block by reporting * to the name-node the actual generation stamp and the length * of the block that the client has transmitted to data-nodes. @@ -372,16 +358,14 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public LocatedBlock addBlock(String src, String clientName, - ExtendedBlock previous, DatanodeInfo[] excludeNodes, long fileId, + LocatedBlock addBlock(String src, String clientName, + ExtendedBlock previous, DatanodeInfo[] excludeNodes, long fileId, String[] favoredNodes) - throws AccessControlException, FileNotFoundException, - NotReplicatedYetException, SafeModeException, UnresolvedLinkException, - IOException; + throws IOException; - /** + /** * Get a datanode for an existing pipeline. - * + * * @param src the file being written * @param fileId the ID of the file being written * @param blk the block being written @@ -389,9 +373,9 @@ public interface ClientProtocol { * @param excludes the excluded nodes * @param numAdditionalNodes number of additional datanodes * @param clientName the name of the client - * + * * @return the located block. - * + * * @throws AccessControlException If access is denied * @throws FileNotFoundException If file src is not found * @throws SafeModeException create not allowed in safemode @@ -399,22 +383,21 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public LocatedBlock getAdditionalDatanode(final String src, + LocatedBlock getAdditionalDatanode(final String src, final long fileId, final ExtendedBlock blk, final DatanodeInfo[] existings, final String[] existingStorageIDs, final DatanodeInfo[] excludes, final int numAdditionalNodes, final String clientName - ) throws AccessControlException, FileNotFoundException, - SafeModeException, UnresolvedLinkException, IOException; + ) throws IOException; /** - * The client is done writing data to the given filename, and would - * like to complete it. + * The client is done writing data to the given filename, and would + * like to complete it. * * The function returns whether the file has been closed successfully. * If the function returns false, the caller should try again. - * + * * close() also commits the last block of file by reporting * to the name-node the actual generation stamp and the length * of the block that the client has transmitted to data-nodes. @@ -434,14 +417,13 @@ public interface ClientProtocol { * @throws AccessControlException If access is denied * @throws FileNotFoundException If file src is not found * @throws SafeModeException create not allowed in safemode - * @throws UnresolvedLinkException If src contains a symlink + * @throws UnresolvedLinkException If src contains a symlink * @throws IOException If an I/O error occurred */ @Idempotent - public boolean complete(String src, String clientName, + boolean complete(String src, String clientName, ExtendedBlock last, long fileId) - throws AccessControlException, FileNotFoundException, SafeModeException, - UnresolvedLinkException, IOException; + throws IOException; /** * The client wants to report corrupted blocks (blocks with specified @@ -449,7 +431,7 @@ public interface ClientProtocol { * @param blocks Array of located blocks to report */ @Idempotent - public void reportBadBlocks(LocatedBlock[] blocks) throws IOException; + void reportBadBlocks(LocatedBlock[] blocks) throws IOException; /////////////////////////////////////// // Namespace management @@ -460,17 +442,17 @@ public interface ClientProtocol { * @param dst new name. * @return true if successful, or false if the old name does not exist * or if the new name already belongs to the namespace. - * + * * @throws SnapshotAccessControlException if path is in RO snapshot - * @throws IOException an I/O error occurred + * @throws IOException an I/O error occurred */ @AtMostOnce - public boolean rename(String src, String dst) - throws UnresolvedLinkException, SnapshotAccessControlException, IOException; + boolean rename(String src, String dst) + throws IOException; /** - * Moves blocks from srcs to trg and delete srcs - * + * Moves blocks from srcs to trg and delete srcs. + * * @param trg existing file * @param srcs - list of existing files (same block size, same replication) * @throws IOException if some arguments are invalid @@ -479,8 +461,8 @@ public interface ClientProtocol { * @throws SnapshotAccessControlException if path is in RO snapshot */ @AtMostOnce - public void concat(String trg, String[] srcs) - throws IOException, UnresolvedLinkException, SnapshotAccessControlException; + void concat(String trg, String[] srcs) + throws IOException; /** * Rename src to dst. @@ -491,7 +473,7 @@ public interface ClientProtocol { * *

* Without OVERWRITE option, rename fails if the dst already exists. - * With OVERWRITE option, rename overwrites the dst, if it is a file + * With OVERWRITE option, rename overwrites the dst, if it is a file * or an empty directory. Rename fails if dst is a non-empty directory. *

* This implementation of rename is atomic. @@ -499,17 +481,17 @@ public interface ClientProtocol { * @param src existing file or directory name. * @param dst new name. * @param options Rename options - * + * * @throws AccessControlException If access is denied - * @throws DSQuotaExceededException If rename violates disk space + * @throws DSQuotaExceededException If rename violates disk space * quota restriction * @throws FileAlreadyExistsException If dst already exists and - * options has {@link Rename#OVERWRITE} option + * options has {@link Rename#OVERWRITE} option * false. * @throws FileNotFoundException If src does not exist - * @throws NSQuotaExceededException If rename violates namespace + * @throws NSQuotaExceededException If rename violates namespace * quota restriction - * @throws ParentNotDirectoryException If parent of dst + * @throws ParentNotDirectoryException If parent of dst * is not a directory * @throws SafeModeException rename not allowed in safemode * @throws UnresolvedLinkException If src or @@ -518,11 +500,8 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @AtMostOnce - public void rename2(String src, String dst, Options.Rename... options) - throws AccessControlException, DSQuotaExceededException, - FileAlreadyExistsException, FileNotFoundException, - NSQuotaExceededException, ParentNotDirectoryException, SafeModeException, - UnresolvedLinkException, SnapshotAccessControlException, IOException; + void rename2(String src, String dst, Options.Rename... options) + throws IOException; /** * Truncate file src to new size. @@ -550,21 +529,20 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public boolean truncate(String src, long newLength, String clientName) - throws AccessControlException, FileNotFoundException, SafeModeException, - UnresolvedLinkException, SnapshotAccessControlException, IOException; + boolean truncate(String src, long newLength, String clientName) + throws IOException; /** * Delete the given file or directory from the file system. *

- * same as delete but provides a way to avoid accidentally - * deleting non empty directories programmatically. + * same as delete but provides a way to avoid accidentally + * deleting non empty directories programmatically. * @param src existing name * @param recursive if true deletes a non empty directory recursively, * else throws an exception. - * @return true only if the existing file or directory was actually removed + * @return true only if the existing file or directory was actually removed * from the file system. - * + * * @throws AccessControlException If access is denied * @throws FileNotFoundException If file src is not found * @throws SafeModeException create not allowed in safemode @@ -573,10 +551,9 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @AtMostOnce - public boolean delete(String src, boolean recursive) - throws AccessControlException, FileNotFoundException, SafeModeException, - UnresolvedLinkException, SnapshotAccessControlException, IOException; - + boolean delete(String src, boolean recursive) + throws IOException; + /** * Create a directory (or hierarchy of directories) with the given * name and permission. @@ -591,8 +568,9 @@ public interface ClientProtocol { * @throws FileAlreadyExistsException If src already exists * @throws FileNotFoundException If parent of src does not exist * and createParent is false - * @throws NSQuotaExceededException If file creation violates quota restriction - * @throws ParentNotDirectoryException If parent of src + * @throws NSQuotaExceededException If file creation violates quota + * restriction + * @throws ParentNotDirectoryException If parent of src * is not a directory * @throws SafeModeException create not allowed in safemode * @throws UnresolvedLinkException If src contains a symlink @@ -603,14 +581,11 @@ public interface ClientProtocol { * @throws InvalidPathException If src is invalid */ @Idempotent - public boolean mkdirs(String src, FsPermission masked, boolean createParent) - throws AccessControlException, FileAlreadyExistsException, - FileNotFoundException, NSQuotaExceededException, - ParentNotDirectoryException, SafeModeException, UnresolvedLinkException, - SnapshotAccessControlException, IOException; + boolean mkdirs(String src, FsPermission masked, boolean createParent) + throws IOException; /** - * Get a partial listing of the indicated directory + * Get a partial listing of the indicated directory. * * @param src the directory name * @param startAfter the name to start listing after encoded in java UTF8 @@ -624,20 +599,17 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public DirectoryListing getListing(String src, - byte[] startAfter, - boolean needLocation) - throws AccessControlException, FileNotFoundException, - UnresolvedLinkException, IOException; - + DirectoryListing getListing(String src, byte[] startAfter, + boolean needLocation) throws IOException; + /** - * Get listing of all the snapshottable directories - * + * Get listing of all the snapshottable directories. + * * @return Information about all the current snapshottable directory * @throws IOException If an I/O error occurred */ @Idempotent - public SnapshottableDirectoryStatus[] getSnapshottableDirListing() + SnapshottableDirectoryStatus[] getSnapshottableDirListing() throws IOException; /////////////////////////////////////// @@ -646,7 +618,7 @@ public interface ClientProtocol { /** * Client programs can cause stateful changes in the NameNode - * that affect other clients. A client may obtain a file and + * that affect other clients. A client may obtain a file and * neither abandon nor complete it. A client might hold a series * of locks that prevent other clients from proceeding. * Clearly, it would be bad if a client held a bunch of locks @@ -664,29 +636,28 @@ public interface ClientProtocol { * @throws IOException If an I/O error occurred */ @Idempotent - public void renewLease(String clientName) throws AccessControlException, - IOException; + void renewLease(String clientName) throws IOException; /** * Start lease recovery. * Lightweight NameNode operation to trigger lease recovery - * + * * @param src path of the file to start lease recovery * @param clientName name of the current client * @return true if the file is already closed * @throws IOException */ @Idempotent - public boolean recoverLease(String src, String clientName) throws IOException; + boolean recoverLease(String src, String clientName) throws IOException; + + int GET_STATS_CAPACITY_IDX = 0; + int GET_STATS_USED_IDX = 1; + int GET_STATS_REMAINING_IDX = 2; + int GET_STATS_UNDER_REPLICATED_IDX = 3; + int GET_STATS_CORRUPT_BLOCKS_IDX = 4; + int GET_STATS_MISSING_BLOCKS_IDX = 5; + int GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX = 6; - public int GET_STATS_CAPACITY_IDX = 0; - public int GET_STATS_USED_IDX = 1; - public int GET_STATS_REMAINING_IDX = 2; - public int GET_STATS_UNDER_REPLICATED_IDX = 3; - public int GET_STATS_CORRUPT_BLOCKS_IDX = 4; - public int GET_STATS_MISSING_BLOCKS_IDX = 5; - public int GET_STATS_MISSING_REPL_ONE_BLOCKS_IDX = 6; - /** * Get a set of statistics about the filesystem. * Right now, only seven values are returned. @@ -700,11 +671,11 @@ public interface ClientProtocol { *

  • [6] contains number of blocks which have replication factor * 1 and have lost the only replica.
    • * - * Use public constants like {@link #GET_STATS_CAPACITY_IDX} in place of + * Use public constants like {@link #GET_STATS_CAPACITY_IDX} in place of * actual numbers to index into the array. */ @Idempotent - public long[] getStats() throws IOException; + long[] getStats() throws IOException; /** * Get a report on the system's current datanodes. @@ -713,14 +684,14 @@ public interface ClientProtocol { * otherwise all datanodes if type is ALL. */ @Idempotent - public DatanodeInfo[] getDatanodeReport(HdfsConstants.DatanodeReportType type) + DatanodeInfo[] getDatanodeReport(HdfsConstants.DatanodeReportType type) throws IOException; /** * Get a report on the current datanode storages. */ @Idempotent - public DatanodeStorageReport[] getDatanodeStorageReport( + DatanodeStorageReport[] getDatanodeStorageReport( HdfsConstants.DatanodeReportType type) throws IOException; /** @@ -728,11 +699,11 @@ public interface ClientProtocol { * @param filename The name of the file * @return The number of bytes in each block * @throws IOException - * @throws UnresolvedLinkException if the path contains a symlink. + * @throws UnresolvedLinkException if the path contains a symlink. */ @Idempotent - public long getPreferredBlockSize(String filename) - throws IOException, UnresolvedLinkException; + long getPreferredBlockSize(String filename) + throws IOException; /** * Enter, leave or get safe mode. @@ -740,16 +711,17 @@ public interface ClientProtocol { * Safe mode is a name node state when it *
    1. does not accept changes to name space (read-only), and
      2. *
    2. does not replicate or delete blocks.
    - * + * *

    * Safe mode is entered automatically at name node startup. * Safe mode can also be entered manually using - * {@link #setSafeMode(HdfsConstants.SafeModeAction,boolean) setSafeMode(SafeModeAction.SAFEMODE_ENTER,false)}. + * {@link #setSafeMode(HdfsConstants.SafeModeAction,boolean) + * setSafeMode(SafeModeAction.SAFEMODE_ENTER,false)}. *

    * At startup the name node accepts data node reports collecting * information about block locations. * In order to leave safe mode it needs to collect a configurable - * percentage called threshold of blocks, which satisfy the minimal + * percentage called threshold of blocks, which satisfy the minimal * replication condition. * The minimal replication condition is that each block must have at least * dfs.namenode.replication.min replicas. @@ -760,37 +732,40 @@ public interface ClientProtocol { * Then the name node leaves safe mode. *

    * If safe mode is turned on manually using - * {@link #setSafeMode(HdfsConstants.SafeModeAction,boolean) setSafeMode(SafeModeAction.SAFEMODE_ENTER,false)} + * {@link #setSafeMode(HdfsConstants.SafeModeAction,boolean) + * setSafeMode(SafeModeAction.SAFEMODE_ENTER,false)} * then the name node stays in safe mode until it is manually turned off - * using {@link #setSafeMode(HdfsConstants.SafeModeAction,boolean) setSafeMode(SafeModeAction.SAFEMODE_LEAVE,false)}. + * using {@link #setSafeMode(HdfsConstants.SafeModeAction,boolean) + * setSafeMode(SafeModeAction.SAFEMODE_LEAVE,false)}. * Current state of the name node can be verified using - * {@link #setSafeMode(HdfsConstants.SafeModeAction,boolean) setSafeMode(SafeModeAction.SAFEMODE_GET,false)} + * {@link #setSafeMode(HdfsConstants.SafeModeAction,boolean) + * setSafeMode(SafeModeAction.SAFEMODE_GET,false)} *

    Configuration parameters:

    * dfs.safemode.threshold.pct is the threshold parameter.
    * dfs.safemode.extension is the safe mode extension parameter.
    * dfs.namenode.replication.min is the minimal replication parameter. - * + * *

    Special cases:

    - * The name node does not enter safe mode at startup if the threshold is + * The name node does not enter safe mode at startup if the threshold is * set to 0 or if the name space is empty.
    - * If the threshold is set to 1 then all blocks need to have at least + * If the threshold is set to 1 then all blocks need to have at least * minimal replication.
    - * If the threshold value is greater than 1 then the name node will not be + * If the threshold value is greater than 1 then the name node will not be * able to turn off safe mode automatically.
    * Safe mode can always be turned off manually. - * + * * @param action * @param isChecked If true then action will be done only in ActiveNN. - * - * @return