Package org.opends.server.backends.jeb

Class JEStorage

java.lang.Object

org.opends.server.backends.jeb.JEStorage

All Implemented Interfaces:

Closeable, AutoCloseable, ConfigurationChangeListener<JeBackendCfg>, DiskSpaceMonitorHandler, Storage, Backupable

public final class JEStorage
extends Object
implements Storage, ConfigurationChangeListener<JeBackendCfg>, DiskSpaceMonitorHandler

Berkeley DB Java Edition (JE for short) database implementation of the Storage engine.

Constructor Summary

Constructors

Constructor	Description
JEStorage(JeBackendCfg cfg, ServerContext serverContext)	Creates a new JE storage with the provided configuration.

Method Summary

Modifier and Type	Method	Description
ConfigChangeResult	applyConfigurationChange(JeBackendCfg cfg)	Applies the configuration changes to this change listener.
void	beforeBackup()	Performs any necessary processing before a backup is performed.
void	close()
void	diskFullThresholdReached(File directory, long thresholdInBytes)	Notifies that the registered "full" threshold have been reached.
void	diskLowThresholdReached(File directory, long thresholdInBytes)	Notifies that the registered "low" threshold have been reached.
void	diskSpaceRestored(File directory, long lowThresholdInBytes, long fullThresholdInBytes)	Notifies that the free disk space is now above both "low" and "full" thresholds.
BackupManager.CountedIterator<BackendFile>	getBackendFiles()	Returns an iterator that goes over all the log files, including files created after this method is called.
String	getBackendID()	Returns the backend name.
Path	getDirectory()	Returns the directory containing all the backend files to be backed up.
StorageStatus	getStorageStatus()	Returns the current status of the storage.
boolean	isConfigurationChangeAcceptable(JeBackendCfg newCfg, List<LocalizableMessage> unacceptableReasons)	Indicates whether the proposed change to the configuration is acceptable to this change listener.
Set<TreeName>	listTrees()	Lists the trees that exist in this storage.
void	open(AccessMode accessMode)	Opens the storage engine to allow executing operations on it.
<T> T	read(ReadOperation<T> operation)	Executes a read operation.
void	removeStorageFiles()	Remove all files for a backend of this storage.
Importer	startImport()	Starts the import operation.
void	write(WriteOperation operation)	Executes a write operation.
void	write(WriteOperation operation, WriteableTransaction.WriteTransactionOption option)	Executes a write operation.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.opends.server.backup.Backupable

afterBackup, afterRestore, beforeRestore

Constructor Detail

JEStorage

public JEStorage(JeBackendCfg cfg,
                 ServerContext serverContext)
          throws ConfigException

Creates a new JE storage with the provided configuration.

Parameters:

cfg - The configuration.

serverContext - This server instance context

Throws:

ConfigException - If there is an error when trying to find the server ID.

Method Detail

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface Storage

open

public void open(AccessMode accessMode)
          throws ConfigException,
                 StorageRuntimeException

Description copied from interface: Storage

Opens the storage engine to allow executing operations on it.

Specified by:

open in interface Storage

Parameters:

accessMode - Specify the access mode to this storage.

Throws:

ConfigException

StorageRuntimeException

See Also:

to release all resources once import is finished

read

public <T> T read(ReadOperation<T> operation)
           throws Exception

Description copied from interface: Storage

Executes a read operation. In case of a read operation rollback, implementations must ensure the read operation is retried until it succeeds.

Specified by:

read in interface Storage

Type Parameters:

T - type of the value returned

Parameters:

operation - the read operation to execute

Returns:

the value read by the read operation

Throws:

Exception - if a problem occurs with the underlying storage engine

startImport

public Importer startImport()
                     throws ConfigException,
                            StorageRuntimeException

Description copied from interface: Storage

Starts the import operation.

Specified by:

startImport in interface Storage

Returns:

a new Importer object which must be closed to release all resources

Throws:

ConfigException - if there is a problem with the configuration

StorageRuntimeException - if a problem occurs with the underlying storage engine

See Also:

to release all resources once import is finished

write

public void write(WriteOperation operation)
           throws Exception

Description copied from interface: Storage

Executes a write operation. In case of a write operation rollback, implementations must ensure the write operation is retried until it succeeds.

Specified by:

write in interface Storage

Parameters:

operation - the write operation to execute

Throws:

Exception - if a problem occurs with the underlying storage engine

write

public void write(WriteOperation operation,
                  WriteableTransaction.WriteTransactionOption option)
           throws Exception

Description copied from interface: Storage

Executes a write operation. In case of a write operation rollback, implementations must ensure the write operation is retried until it succeeds.

Specified by:

write in interface Storage

Parameters:

operation - the write operation to execute

option - the option to apply to this transaction

Throws:

Exception - if a problem occurs with the underlying storage engine

getDirectory

public Path getDirectory()

Description copied from interface: Backupable

Returns the directory containing all the backend files to be backed up.

Specified by:

getDirectory in interface Backupable

Returns:

the directory containing all the backend files to be backed up.

getBackendID

public String getBackendID()

Description copied from interface: Backupable

Returns the backend name.

Specified by:

getBackendID in interface Backupable

Returns:

the backend name.

getBackendFiles

public BackupManager.CountedIterator<BackendFile> getBackendFiles()
                                                           throws IOException

Returns an iterator that goes over all the log files, including files created after this method is called. The iterator may return files that have been deleted, such files should be ignored during iteration.

A file fingerprint is calculated just before the file is sent to the backup storage , this means that, by the time the last byte of a file is sent to a backup storage, the fingerprint may be inaccurate. At worse this will cause two identical files to be stored twice in a backup storage, consider the following as an example: the Computed fingerprint is serverId_appData_100, the actual fingerprint is serverId_appData_150. It is impossible for the backup storage to already have a file with fingerprint serverId_appData_150 because files are append only.

• The backup storage already contains a file with fingerprint serverId_appData_100: the backup reuses that file and the last 50 bytes are not backed up.
• The backup storage does not contain a file with fingerprint serverId_appData_100: the file is transferred to the backup storage with fingerprint serverId_appData_100 but actual fingerprint is serverId_appData_150.

  During the next backup:

• The file has not changed: computed fingerprint is serverId_appData_150, the backup storage does not have any record of a file with fingerprint serverId_appData_150, the file is stored again in the backup storage even though it was already stored during the last backup.
• The file has changed: computed fingerprint is serverId_appData_200, the new file is sent to the backup storage.

Specified by:

getBackendFiles in interface Backupable

Returns:

A backend file iterator.

Throws:

IOException - If there is an error when trying to find the backend files.

beforeBackup

public void beforeBackup()

Description copied from interface: Backupable

Performs any necessary processing before a backup is performed. For example, this can take a shared lock or flush out a memory cache to backend files or delete stale data files.

Specified by:

beforeBackup in interface Backupable

listTrees

public Set<TreeName> listTrees()

Description copied from interface: Storage

Lists the trees that exist in this storage.

Specified by:

listTrees in interface Storage

Returns:

a set of TreeNames representing the trees that exist in this storage

isConfigurationChangeAcceptable

public boolean isConfigurationChangeAcceptable(JeBackendCfg newCfg,
                                               List<LocalizableMessage> unacceptableReasons)

Description copied from interface: ConfigurationChangeListener

Indicates whether the proposed change to the configuration is acceptable to this change listener.

Specified by:

isConfigurationChangeAcceptable in interface ConfigurationChangeListener<JeBackendCfg>

Parameters:

newCfg - The new configuration containing the changes.

unacceptableReasons - A list that can be used to hold messages about why the provided configuration is not acceptable.

Returns:

Returns true if the proposed change is acceptable, or false if it is not.

applyConfigurationChange

public ConfigChangeResult applyConfigurationChange(JeBackendCfg cfg)

Description copied from interface: ConfigurationChangeListener

Applies the configuration changes to this change listener.

Specified by:

applyConfigurationChange in interface ConfigurationChangeListener<JeBackendCfg>

Parameters:

cfg - The new configuration containing the changes.

Returns:

Returns information about the result of changing the configuration.

removeStorageFiles

public void removeStorageFiles()
                        throws StorageRuntimeException

Description copied from interface: Storage

Remove all files for a backend of this storage.

Specified by:

removeStorageFiles in interface Storage

Throws:

StorageRuntimeException - if removal fails

getStorageStatus

public StorageStatus getStorageStatus()

Description copied from interface: Storage

Returns the current status of the storage.

Specified by:

getStorageStatus in interface Storage

Returns:

the current status of the storage

diskFullThresholdReached

public void diskFullThresholdReached(File directory,
                                     long thresholdInBytes)

Description copied from interface: DiskSpaceMonitorHandler

Notifies that the registered "full" threshold have been reached.

Specified by:

diskFullThresholdReached in interface DiskSpaceMonitorHandler

Parameters:

directory - the directory for which the threshold has been triggered

thresholdInBytes - the threshold value in bytes

diskLowThresholdReached

public void diskLowThresholdReached(File directory,
                                    long thresholdInBytes)

Description copied from interface: DiskSpaceMonitorHandler

Notifies that the registered "low" threshold have been reached.

Specified by:

diskLowThresholdReached in interface DiskSpaceMonitorHandler

Parameters:

directory - the directory for which the threshold has been triggered

thresholdInBytes - the threshold value in bytes

diskSpaceRestored

public void diskSpaceRestored(File directory,
                              long lowThresholdInBytes,
                              long fullThresholdInBytes)

Description copied from interface: DiskSpaceMonitorHandler

Notifies that the free disk space is now above both "low" and "full" thresholds.

Specified by:

diskSpaceRestored in interface DiskSpaceMonitorHandler

Parameters:

directory - the directory for which the threshold has been triggeredTODO

lowThresholdInBytes - the low threshold value in bytes

fullThresholdInBytes - the full threshold value in bytes