Package org.apache.hadoop.hdfs.protocol

Interface ClientDatanodeProtocol

All Known Implementing Classes:

ClientDatanodeProtocolTranslatorPB

@Private
@Evolving
public interface ClientDatanodeProtocol

An client-datanode protocol for block recovery

Field Summary

Fields

Modifier and Type	Field	Description
static long	versionID	Until version 9, this class ClientDatanodeProtocol served as both the client interface to the DN AND the RPC protocol used to communicate with the NN.

Method Summary

Modifier and Type	Method	Description
void	cancelDiskBalancePlan(java.lang.String planID)	Cancel an executing plan.
void	deleteBlockPool(java.lang.String bpid, boolean force)	Delete the block pool directory.
void	evictWriters()	Evict clients that are writing to a datanode.
long	getBalancerBandwidth()	Get current value of the balancer bandwidth in bytes per second.
BlockLocalPathInfo	getBlockLocalPathInfo(ExtendedBlock block, org.apache.hadoop.security.token.Token<BlockTokenIdentifier> token)	Retrieves the path names of the block file and metadata file stored on the local file system.
DatanodeLocalInfo	getDatanodeInfo()	Obtains datanode info
java.lang.String	getDiskBalancerSetting(java.lang.String key)	Gets a run-time configuration value from running diskbalancer instance.
org.apache.hadoop.conf.ReconfigurationTaskStatus	getReconfigurationStatus()	Get the status of the previously issued reconfig task.
long	getReplicaVisibleLength(ExtendedBlock b)	Return the visible length of a replica.
java.util.List<DatanodeVolumeInfo>	getVolumeReport()	Get volume report of datanode.
java.util.List<java.lang.String>	listReconfigurableProperties()	Get a list of allowed properties for reconfiguration.
DiskBalancerWorkStatus	queryDiskBalancerPlan()	Gets the status of an executing diskbalancer Plan.
void	refreshNamenodes()	Refresh the list of federated namenodes from updated configuration Adds new namenodes and stops the deleted namenodes.
void	shutdownDatanode(boolean forUpgrade)	Shuts down a datanode.
void	startReconfiguration()	Asynchronously reload configuration on disk and apply changes.
void	submitDiskBalancerPlan(java.lang.String planID, long planVersion, java.lang.String planFile, java.lang.String planData, boolean skipDateCheck)	Submit a disk balancer plan for execution.
void	triggerBlockReport(BlockReportOptions options)	Trigger a new block report.

Field Detail

versionID

static final long versionID

Until version 9, this class ClientDatanodeProtocol served as both the client interface to the DN AND the RPC protocol used to communicate with the NN. This class is used by both the DFSClient and the DN server side to insulate from the protocol serialization. If you are adding/changing DN's interface then you need to change both this class and ALSO related protocol buffer wire protocol definition in ClientDatanodeProtocol.proto. 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). 9: Added deleteBlockPool method 9 is the last version id when this class was used for protocols serialization. DO not update this version any further.

See Also:

Constant Field Values

Method Detail

getReplicaVisibleLength

long getReplicaVisibleLength(ExtendedBlock b)
                      throws java.io.IOException

Return the visible length of a replica.

Throws:

java.io.IOException

refreshNamenodes

void refreshNamenodes()
               throws java.io.IOException

Refresh the list of federated namenodes from updated configuration Adds new namenodes and stops the deleted namenodes.

Throws:

java.io.IOException - on error

deleteBlockPool

void deleteBlockPool(java.lang.String bpid,
                     boolean force)
              throws java.io.IOException

Delete the block pool directory. If force is false it is deleted only if it is empty, otherwise it is deleted along with its contents.

Parameters:

bpid - Blockpool id to be deleted.

force - If false blockpool directory is deleted only if it is empty i.e. if it doesn't contain any block files, otherwise it is deleted along with its contents.

Throws:

java.io.IOException

getBlockLocalPathInfo

BlockLocalPathInfo getBlockLocalPathInfo(ExtendedBlock block,
                                         org.apache.hadoop.security.token.Token<BlockTokenIdentifier> token)
                                  throws java.io.IOException

Retrieves the path names of the block file and metadata file stored on the local file system. In order for this method to work, one of the following should be satisfied:

• The client user must be configured at the datanode to be able to use this method.
• When security is enabled, kerberos authentication must be used to connect to the datanode.

Parameters:

block - the specified block on the local datanode

token - the block access token.

Returns:

the BlockLocalPathInfo of a block

Throws:

java.io.IOException - on error

shutdownDatanode

void shutdownDatanode(boolean forUpgrade)
               throws java.io.IOException

Shuts down a datanode.

Parameters:

forUpgrade - If true, data node does extra prep work before shutting down. The work includes advising clients to wait and saving certain states for quick restart. This should only be used when the stored data will remain the same during upgrade/restart.

Throws:

java.io.IOException

evictWriters

void evictWriters()
           throws java.io.IOException

Evict clients that are writing to a datanode.

Throws:

java.io.IOException

getDatanodeInfo

DatanodeLocalInfo getDatanodeInfo()
                           throws java.io.IOException

Obtains datanode info

Returns:

software/config version and uptime of the datanode

Throws:

java.io.IOException

startReconfiguration

void startReconfiguration()
                   throws java.io.IOException

Asynchronously reload configuration on disk and apply changes.

Throws:

java.io.IOException

getReconfigurationStatus

org.apache.hadoop.conf.ReconfigurationTaskStatus getReconfigurationStatus()
                                                                   throws java.io.IOException

Get the status of the previously issued reconfig task.

Throws:

java.io.IOException

See Also:

ReconfigurationTaskStatus

listReconfigurableProperties

java.util.List<java.lang.String> listReconfigurableProperties()
                                                       throws java.io.IOException

Get a list of allowed properties for reconfiguration.

Throws:

java.io.IOException

triggerBlockReport

void triggerBlockReport(BlockReportOptions options)
                 throws java.io.IOException

Trigger a new block report.

Throws:

java.io.IOException

getBalancerBandwidth

long getBalancerBandwidth()
                   throws java.io.IOException

Get current value of the balancer bandwidth in bytes per second.

Returns:

balancer bandwidth

Throws:

java.io.IOException

getVolumeReport

java.util.List<DatanodeVolumeInfo> getVolumeReport()
                                            throws java.io.IOException

Get volume report of datanode.

Throws:

java.io.IOException

submitDiskBalancerPlan

void submitDiskBalancerPlan(java.lang.String planID,
                            long planVersion,
                            java.lang.String planFile,
                            java.lang.String planData,
                            boolean skipDateCheck)
                     throws java.io.IOException

Submit a disk balancer plan for execution.

Throws:

java.io.IOException

cancelDiskBalancePlan

void cancelDiskBalancePlan(java.lang.String planID)
                    throws java.io.IOException

Cancel an executing plan.

Parameters:

planID - - A SHA-1 hash of the plan string.

Throws:

java.io.IOException

queryDiskBalancerPlan

DiskBalancerWorkStatus queryDiskBalancerPlan()
                                      throws java.io.IOException

Gets the status of an executing diskbalancer Plan.

Throws:

java.io.IOException

getDiskBalancerSetting

java.lang.String getDiskBalancerSetting(java.lang.String key)
                                 throws java.io.IOException

Gets a run-time configuration value from running diskbalancer instance. For example : Disk Balancer bandwidth of a running instance.

Parameters:

key - runtime configuration key

Returns:

value of the key as a string.

Throws:

java.io.IOException - - Throws if there is no such key