org.janusgraph.diskstorage

Class Backend

java.lang.Object

org.janusgraph.diskstorage.Backend

All Implemented Interfaces:

AutoCloseable, LockerProvider

public class Backend
extends Object
implements LockerProvider, AutoCloseable

Orchestrates and configures all backend systems: The primary backend storage (KeyColumnValueStore) and all external indexing providers (IndexProvider).

Author:

Matthias Broecheler ([email protected])

Field Summary

Fields

Modifier and Type	Field and Description
static double	EDGESTORE_CACHE_PERCENT
static String	EDGESTORE_NAME These are the names for the edge store and property index databases, respectively.
static double	INDEXSTORE_CACHE_PERCENT
static String	INDEXSTORE_NAME
static String	LOCK_STORE_SUFFIX
static String	METRICS_CACHE_SUFFIX
static String	METRICS_INDEX_PROVIDER_NAME
static String	METRICS_MERGED_CACHE
static String	METRICS_MERGED_STORE
static String	METRICS_STOREMANAGER_NAME
static Map<String,String>	REGISTERED_LOG_MANAGERS
static String	SYSTEM_MGMT_LOG_NAME
static String	SYSTEM_TX_LOG_NAME

Constructor Summary

Constructors

Constructor and Description
Backend(Configuration configuration)

Method Summary

Modifier and Type	Method and Description
BackendTransaction	beginTransaction(TransactionConfiguration configuration, KeyInformation.Retriever indexKeyRetriever) Opens a new transaction against all registered backend system wrapped in one BackendTransaction.
StandardScanner.Builder	buildEdgeScanJob()
StandardScanner.Builder	buildGraphIndexScanJob()
void	clearStorage() Clears the storage of all registered backend data providers.
void	close()
KCVSConfiguration	getGlobalSystemConfig()
IDAuthority	getIDAuthority() Returns the configured IDAuthority.
static <T> T	getImplementationClass(Configuration config, String className, Map<String,String> registeredImplementations)
Map<String,IndexFeatures>	getIndexFeatures() Returns the IndexFeatures of all configured index backends
Map<String,IndexInformation>	getIndexInformation() Get information about all registered IndexProviders.
KCVSLogManager	getKCVSLogManager(String logName)
Locker	getLocker(String lockerName)
LogManager	getLogManager(String logName)
static ConfigOption<?>	getOptionForShorthand(String shorthand)
JanusGraphManagement.IndexJobFuture	getScanJobStatus(Object jobId)
static KeyColumnValueStoreManager	getStorageManager(Configuration storageConfig)
StoreFeatures	getStoreFeatures() Returns the StoreFeatures of the configured backend storage engine.
StoreManager	getStoreManager()
Class<? extends KeyColumnValueStoreManager>	getStoreManagerClass()
Log	getSystemMgmtLog()
KCVSLog	getSystemTxLog()
KCVSConfiguration	getUserConfiguration()
Log	getUserLog(String identifier)
static String	getUserLogName(String identifier)
void	initialize(Configuration config) Initializes this backend with the given configuration.

Methods inherited from class java.lang.Object

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

Field Detail

EDGESTORE_NAME

public static final String EDGESTORE_NAME

These are the names for the edge store and property index databases, respectively. The edge store contains all edges and properties. The property index contains an inverted index from attribute value to vertex.

These names are fixed and should NEVER be changed. Changing these strings can disrupt storage adapters that rely on these names for specific configurations. In the past, the store name for the ID table, janusgraph_ids, was also marked here, but to clear the upgrade path from Titan to JanusGraph, we had to pull it into configuration.

See Also:

Constant Field Values

INDEXSTORE_NAME

public static final String INDEXSTORE_NAME

See Also:

Constant Field Values

METRICS_STOREMANAGER_NAME

public static final String METRICS_STOREMANAGER_NAME

See Also:

Constant Field Values

METRICS_MERGED_STORE

public static final String METRICS_MERGED_STORE

See Also:

Constant Field Values

METRICS_MERGED_CACHE

public static final String METRICS_MERGED_CACHE

See Also:

Constant Field Values

METRICS_CACHE_SUFFIX

public static final String METRICS_CACHE_SUFFIX

See Also:

Constant Field Values

METRICS_INDEX_PROVIDER_NAME

public static final String METRICS_INDEX_PROVIDER_NAME

See Also:

Constant Field Values

LOCK_STORE_SUFFIX

public static final String LOCK_STORE_SUFFIX

See Also:

Constant Field Values

SYSTEM_TX_LOG_NAME

public static final String SYSTEM_TX_LOG_NAME

See Also:

Constant Field Values

SYSTEM_MGMT_LOG_NAME

public static final String SYSTEM_MGMT_LOG_NAME

See Also:

Constant Field Values

EDGESTORE_CACHE_PERCENT

public static final double EDGESTORE_CACHE_PERCENT

See Also:

Constant Field Values

INDEXSTORE_CACHE_PERCENT

public static final double INDEXSTORE_CACHE_PERCENT

See Also:

Constant Field Values

REGISTERED_LOG_MANAGERS

public static final Map<String,String> REGISTERED_LOG_MANAGERS

Constructor Detail

Backend

public Backend(Configuration configuration)

Method Detail

getLocker

public Locker getLocker(String lockerName)

Specified by:

getLocker in interface LockerProvider

initialize

public void initialize(Configuration config)

Initializes this backend with the given configuration. Must be called before this Backend can be used

Parameters:

config -

getIndexInformation

public Map<String,IndexInformation> getIndexInformation()

Get information about all registered IndexProviders.

Returns:

getSystemTxLog

public KCVSLog getSystemTxLog()

getSystemMgmtLog

public Log getSystemMgmtLog()

buildEdgeScanJob

public StandardScanner.Builder buildEdgeScanJob()

buildGraphIndexScanJob

public StandardScanner.Builder buildGraphIndexScanJob()

getScanJobStatus

public JanusGraphManagement.IndexJobFuture getScanJobStatus(Object jobId)

getUserLog

public Log getUserLog(String identifier)
               throws BackendException

Throws:

BackendException

getUserLogName

public static String getUserLogName(String identifier)

getGlobalSystemConfig

public KCVSConfiguration getGlobalSystemConfig()

getUserConfiguration

public KCVSConfiguration getUserConfiguration()

getKCVSLogManager

public KCVSLogManager getKCVSLogManager(String logName)

getLogManager

public LogManager getLogManager(String logName)

getStorageManager

public static KeyColumnValueStoreManager getStorageManager(Configuration storageConfig)

getImplementationClass

public static <T> T getImplementationClass(Configuration config,
                                           String className,
                                           Map<String,String> registeredImplementations)

getIDAuthority

public IDAuthority getIDAuthority()

Returns the configured IDAuthority.

Returns:

getStoreFeatures

public StoreFeatures getStoreFeatures()

Returns the StoreFeatures of the configured backend storage engine.

Returns:

getStoreManagerClass

public Class<? extends KeyColumnValueStoreManager> getStoreManagerClass()

getStoreManager

public StoreManager getStoreManager()

getIndexFeatures

public Map<String,IndexFeatures> getIndexFeatures()

Returns the IndexFeatures of all configured index backends

beginTransaction

public BackendTransaction beginTransaction(TransactionConfiguration configuration,
                                           KeyInformation.Retriever indexKeyRetriever)
                                    throws BackendException

Opens a new transaction against all registered backend system wrapped in one BackendTransaction.

Returns:

Throws:

BackendException

close

public void close()
           throws BackendException

Specified by:

close in interface AutoCloseable

Throws:

BackendException

clearStorage

public void clearStorage()
                  throws BackendException

Clears the storage of all registered backend data providers. This includes backend storage engines and index providers.

IMPORTANT: Clearing storage means that ALL data will be lost and cannot be recovered.

Throws:

BackendException

getOptionForShorthand

public static ConfigOption<?> getOptionForShorthand(String shorthand)