voldemort.store.metadata
Class MetadataStore

java.lang.Object
  voldemort.store.metadata.MetadataStore

All Implemented Interfaces:

StorageEngine<ByteArray,byte[],byte[]>, Store<ByteArray,byte[],byte[]>

public class MetadataStore
extends java.lang.Object
implements StorageEngine<ByteArray,byte[],byte[]>

MetadataStore maintains metadata for Voldemort Server.
Metadata is persisted as strings in inner store for ease of readability.
Metadata Store keeps an in memory write-through-cache for performance.

Nested Class Summary

static class

MetadataStore.VoldemortState

Field Summary

static java.lang.String	CLUSTER_KEY
static java.util.Set<java.lang.String>	GOSSIP_KEYS
static java.util.Set<java.lang.Object>	METADATA_KEYS
static java.lang.String	METADATA_STORE_NAME
static java.lang.String	NODE_ID_KEY
static java.util.Set<java.lang.String>	OPTIONAL_KEYS
java.util.concurrent.locks.Lock	readLock
static java.lang.String	REBALANCING_STEAL_INFO
static java.util.Set<java.lang.String>	REQUIRED_KEYS
static java.lang.String	SERVER_STATE_KEY
static java.lang.String	STORES_KEY
static java.lang.String	SYSTEM_STORES_KEY
java.util.concurrent.locks.Lock	writeLock

Constructor Summary

MetadataStore(Store<java.lang.String,java.lang.String,java.lang.String> innerStore, int nodeId)

Method Summary

void	addMetadataStoreListener(java.lang.String storeName, MetadataStoreListener listener)
void	addRebalancingState(RebalancePartitionsInfo stealInfo) Add the steal information to the rebalancer state
boolean	beginBatchModifications() A lot of storage engines support efficient methods for performing large number of writes (puts/deletes) against the data source.
void	cleanAllRebalancingState()
void	close() Close the store.
boolean	delete(ByteArray key, Version version) Delete all entries prior to the given version
void	deleteRebalancingState(RebalancePartitionsInfo stealInfo) Delete the partition steal information from the rebalancer state
boolean	endBatchModifications()
ClosableIterator<Pair<ByteArray,Versioned<byte[]>>>	entries() Get an iterator over pairs of entries in the store.
ClosableIterator<Pair<ByteArray,Versioned<byte[]>>>	entries(int partition) Get an iterator over pairs of entries in a store's partition.
java.util.List<Versioned<byte[]>>	get(ByteArray keyBytes, byte[] transforms) Get the value associated with the given key
java.util.List<Versioned<byte[]>>	get(java.lang.String key, java.lang.String transforms)
java.util.Map<ByteArray,java.util.List<Versioned<byte[]>>>	getAll(java.lang.Iterable<ByteArray> keys, java.util.Map<ByteArray,byte[]> transforms) Get the values associated with the given keys and returns them in a Map of keys to a list of versioned values.
java.lang.Object	getCapability(StoreCapabilityType capability) Get some capability of the store.
Cluster	getCluster()
java.lang.String	getName()
int	getNodeId()
RebalancerState	getRebalancerState()
RoutingStrategy	getRoutingStrategy(java.lang.String storeName)
MetadataStore.VoldemortState	getServerState()
StoreDefinition	getStoreDef(java.lang.String storeName)
java.util.List<StoreDefinition>	getStoreDefList()
java.util.List<StoreDefinition>	getSystemStoreDefList()
java.util.List<Version>	getVersions(ByteArray key)
boolean	isPartitionAware() Is the data persistence aware of partitions? In other words is the data internally stored on a per partition basis or together
boolean	isPartitionScanSupported() Does the storage engine support efficient scanning of a single partition
ClosableIterator<ByteArray>	keys() Get an iterator over keys in the store.
ClosableIterator<ByteArray>	keys(int partition) Get an iterator over keys in the store's partition Note that the iterator need not be threadsafe, and that it must be manually closed after use.
void	put(ByteArray keyBytes, Versioned<byte[]> valueBytes, byte[] transforms) A write through put to inner-store.
void	put(java.lang.String key, java.lang.Object value) helper function to read current version and put() after incrementing it for local node.
void	put(java.lang.String key, Versioned<java.lang.Object> value) helper function to convert strings to bytes as needed.
static MetadataStore	readFromDirectory(java.io.File dir, int nodeId)
void	removeMetadataStoreListener(java.lang.String storeName)
void	truncate() Truncate all entries in the store

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

METADATA_STORE_NAME

public static final java.lang.String METADATA_STORE_NAME

See Also:

Constant Field Values

CLUSTER_KEY

public static final java.lang.String CLUSTER_KEY

See Also:

Constant Field Values

STORES_KEY

public static final java.lang.String STORES_KEY

See Also:

Constant Field Values

SYSTEM_STORES_KEY

public static final java.lang.String SYSTEM_STORES_KEY

See Also:

Constant Field Values

SERVER_STATE_KEY

public static final java.lang.String SERVER_STATE_KEY

See Also:

Constant Field Values

NODE_ID_KEY

public static final java.lang.String NODE_ID_KEY

See Also:

Constant Field Values

REBALANCING_STEAL_INFO

public static final java.lang.String REBALANCING_STEAL_INFO

See Also:

Constant Field Values

GOSSIP_KEYS

public static final java.util.Set<java.lang.String> GOSSIP_KEYS

REQUIRED_KEYS

public static final java.util.Set<java.lang.String> REQUIRED_KEYS

OPTIONAL_KEYS

public static final java.util.Set<java.lang.String> OPTIONAL_KEYS

METADATA_KEYS

public static final java.util.Set<java.lang.Object> METADATA_KEYS

readLock

public final java.util.concurrent.locks.Lock readLock

writeLock

public final java.util.concurrent.locks.Lock writeLock

Constructor Detail

MetadataStore

public MetadataStore(Store<java.lang.String,java.lang.String,java.lang.String> innerStore,
                     int nodeId)

Method Detail

addMetadataStoreListener

public void addMetadataStoreListener(java.lang.String storeName,
                                     MetadataStoreListener listener)

removeMetadataStoreListener

public void removeMetadataStoreListener(java.lang.String storeName)

readFromDirectory

public static MetadataStore readFromDirectory(java.io.File dir,
                                              int nodeId)

getName

public java.lang.String getName()

Specified by:

getName in interface Store<ByteArray,byte[],byte[]>

Returns:

The name of the store.

put

public void put(java.lang.String key,
                Versioned<java.lang.Object> value)

helper function to convert strings to bytes as needed.

Parameters:

key -

value -

put

public void put(java.lang.String key,
                java.lang.Object value)

helper function to read current version and put() after incrementing it for local node.

Parameters:

key -

value -

put

public void put(ByteArray keyBytes,
                Versioned<byte[]> valueBytes,
                byte[] transforms)
         throws VoldemortException

A write through put to inner-store.

Specified by:

put in interface Store<ByteArray,byte[],byte[]>

Parameters:

keyBytes - : keyName strings serialized as bytes eg. 'cluster.xml'

valueBytes - : versioned byte[] eg. UTF bytes for cluster xml definitions

Throws:

VoldemortException

close

public void close()
           throws VoldemortException

Description copied from interface: Store

Close the store.

Specified by:

close in interface Store<ByteArray,byte[],byte[]>

Throws:

VoldemortException - If closing fails.

getCapability

public java.lang.Object getCapability(StoreCapabilityType capability)

Description copied from interface: Store

Get some capability of the store. Examples would be the serializer used, or the routing strategy. This provides a mechanism to verify that the store hierarchy has some set of capabilities without knowing the precise layering.

Specified by:

getCapability in interface Store<ByteArray,byte[],byte[]>

Parameters:

capability - The capability type to retrieve

Returns:

The given capaiblity

get

public java.util.List<Versioned<byte[]>> get(ByteArray keyBytes,
                                             byte[] transforms)
                                      throws VoldemortException

Description copied from interface: Store

Get the value associated with the given key

Specified by:

get in interface Store<ByteArray,byte[],byte[]>

Parameters:

keyBytes - : keyName strings serialized as bytes eg. 'cluster.xml'

Returns:

List of values (only 1 for Metadata) versioned byte[] eg. UTF bytes for cluster xml definitions

Throws:

VoldemortException

get

public java.util.List<Versioned<byte[]>> get(java.lang.String key,
                                             java.lang.String transforms)
                                      throws VoldemortException

Throws:

VoldemortException

cleanAllRebalancingState

public void cleanAllRebalancingState()

getVersions

public java.util.List<Version> getVersions(ByteArray key)

Specified by:

getVersions in interface Store<ByteArray,byte[],byte[]>

getCluster

public Cluster getCluster()

getStoreDefList

public java.util.List<StoreDefinition> getStoreDefList()

getSystemStoreDefList

public java.util.List<StoreDefinition> getSystemStoreDefList()

getNodeId

public int getNodeId()

getStoreDef

public StoreDefinition getStoreDef(java.lang.String storeName)

getServerState

public MetadataStore.VoldemortState getServerState()

getRebalancerState

public RebalancerState getRebalancerState()

getRoutingStrategy

public RoutingStrategy getRoutingStrategy(java.lang.String storeName)

addRebalancingState

public void addRebalancingState(RebalancePartitionsInfo stealInfo)

Add the steal information to the rebalancer state

Parameters:

stealInfo - The steal information to add

deleteRebalancingState

public void deleteRebalancingState(RebalancePartitionsInfo stealInfo)

Delete the partition steal information from the rebalancer state

Parameters:

stealInfo - The steal information to delete

entries

public ClosableIterator<Pair<ByteArray,Versioned<byte[]>>> entries()

Description copied from interface: StorageEngine

Get an iterator over pairs of entries in the store. The key is the first element in the pair and the versioned value is the second element. Note that the iterator need not be threadsafe, and that it must be manually closed after use.

Specified by:

entries in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

An iterator over the entries in this StorageEngine.

keys

public ClosableIterator<ByteArray> keys()

Description copied from interface: StorageEngine

Get an iterator over keys in the store. Note that the iterator need not be threadsafe, and that it must be manually closed after use.

Specified by:

keys in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

An iterator over the keys in this StorageEngine.

entries

public ClosableIterator<Pair<ByteArray,Versioned<byte[]>>> entries(int partition)

Description copied from interface: StorageEngine

Get an iterator over pairs of entries in a store's partition. The key is the first element in the pair and the versioned value is the second element. Note that the iterator need not be threadsafe, and that it must be manually closed after use.

Specified by:

entries in interface StorageEngine<ByteArray,byte[],byte[]>

Parameters:

partition - partition whose entries are to be fetched

Returns:

An iterator over the entries in this StorageEngine.

keys

public ClosableIterator<ByteArray> keys(int partition)

Description copied from interface: StorageEngine

Get an iterator over keys in the store's partition Note that the iterator need not be threadsafe, and that it must be manually closed after use.

Specified by:

keys in interface StorageEngine<ByteArray,byte[],byte[]>

Parameters:

partition - partition whose keys are to be fetched

Returns:

An iterator over the keys in this StorageEngine.

truncate

public void truncate()

Description copied from interface: StorageEngine

Truncate all entries in the store

Specified by:

truncate in interface StorageEngine<ByteArray,byte[],byte[]>

delete

public boolean delete(ByteArray key,
                      Version version)
               throws VoldemortException

Description copied from interface: Store

Delete all entries prior to the given version

Specified by:

delete in interface Store<ByteArray,byte[],byte[]>

Parameters:

key - The key to delete

version - The current value of the key

Returns:

True if anything was deleted

Throws:

VoldemortException

getAll

public java.util.Map<ByteArray,java.util.List<Versioned<byte[]>>> getAll(java.lang.Iterable<ByteArray> keys,
                                                                         java.util.Map<ByteArray,byte[]> transforms)
                                                                  throws VoldemortException

Description copied from interface: Store

Get the values associated with the given keys and returns them in a Map of keys to a list of versioned values. Note that the returned map will only contain entries for the keys which have a value associated with them.

Specified by:

getAll in interface Store<ByteArray,byte[],byte[]>

Parameters:

keys - The keys to check for.

Returns:

A Map of keys to a list of versioned values.

Throws:

VoldemortException

isPartitionAware

public boolean isPartitionAware()

Description copied from interface: StorageEngine

Is the data persistence aware of partitions? In other words is the data internally stored on a per partition basis or together

Specified by:

isPartitionAware in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

Boolean indicating if the data persistence is partition aware

isPartitionScanSupported

public boolean isPartitionScanSupported()

Description copied from interface: StorageEngine

Does the storage engine support efficient scanning of a single partition

Specified by:

isPartitionScanSupported in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

true if the storage engine implements the capability. false otherwise

beginBatchModifications

public boolean beginBatchModifications()

Description copied from interface: StorageEngine

A lot of storage engines support efficient methods for performing large number of writes (puts/deletes) against the data source. This method puts the storage engine in this batch write mode

Specified by:

beginBatchModifications in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

true if the storage engine took successful action to switch to 'batch-write' mode

endBatchModifications

public boolean endBatchModifications()

Specified by:

endBatchModifications in interface StorageEngine<ByteArray,byte[],byte[]>

Returns:

true if the storage engine successfully returned to normal mode