Package org.apache.hadoop.hdfs.server.aliasmap

Interface InMemoryAliasMapProtocol

All Known Implementing Classes:

InMemoryAliasMap, InMemoryAliasMapProtocolClientSideTranslatorPB, InMemoryLevelDBAliasMapServer

@Private
@Unstable
public interface InMemoryAliasMapProtocol

Protocol used by clients to read/write data about aliases of provided blocks for an in-memory implementation of the BlockAliasMap.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	InMemoryAliasMapProtocol.IterationResult	The result of a read from the in-memory aliasmap.

Method Summary

Modifier and Type	Method	Description
java.lang.String	getBlockPoolId()	Get the associated block pool id.
InMemoryAliasMapProtocol.IterationResult	list(java.util.Optional<org.apache.hadoop.hdfs.protocol.Block> marker)	List the next batch of FileRegions in the alias map starting from the given marker.
java.util.Optional<org.apache.hadoop.hdfs.protocol.ProvidedStorageLocation>	read(org.apache.hadoop.hdfs.protocol.Block block)	Gets the ProvidedStorageLocation associated with the specified block.
void	write(org.apache.hadoop.hdfs.protocol.Block block, org.apache.hadoop.hdfs.protocol.ProvidedStorageLocation providedStorageLocation)	Stores the block and it's associated ProvidedStorageLocation in the alias map.

Method Detail

list

InMemoryAliasMapProtocol.IterationResult list(java.util.Optional<org.apache.hadoop.hdfs.protocol.Block> marker)
                                       throws java.io.IOException

List the next batch of FileRegions in the alias map starting from the given marker. To retrieve all FileRegions stored in the alias map, multiple calls to this function might be required.

Parameters:

marker - the next block to get fileregions from.

Returns:

the InMemoryAliasMapProtocol.IterationResult with a set of FileRegions and the next marker.

Throws:

java.io.IOException

read

@Nonnull
java.util.Optional<org.apache.hadoop.hdfs.protocol.ProvidedStorageLocation> read(@Nonnull
                                                                                 org.apache.hadoop.hdfs.protocol.Block block)
                                                                          throws java.io.IOException

Gets the ProvidedStorageLocation associated with the specified block.

Parameters:

block - the block to lookup

Returns:

the associated ProvidedStorageLocation.

Throws:

java.io.IOException

write

void write(@Nonnull
           org.apache.hadoop.hdfs.protocol.Block block,
           @Nonnull
           org.apache.hadoop.hdfs.protocol.ProvidedStorageLocation providedStorageLocation)
    throws java.io.IOException

Stores the block and it's associated ProvidedStorageLocation in the alias map.

Parameters:

block -

providedStorageLocation -

Throws:

java.io.IOException

getBlockPoolId

java.lang.String getBlockPoolId()
                         throws java.io.IOException

Get the associated block pool id.

Returns:

the block pool id associated with the Namenode running the in-memory alias map.

Throws:

java.io.IOException