com.sleepycat.je.rep.impl.networkRestore

Class NetworkBackup

java.lang.Object

com.sleepycat.je.rep.impl.networkRestore.NetworkBackup

public class NetworkBackup
extends Object

This class implements a hot network backup that permits it to obtain a consistent set of log files from any running environment that provides a LogFileFeeder service. This class thus plays the role of a client, and the running environment that of a server.

The log files that are retrieved over the network are placed in a directory that can serve as an environment directory for a JE stand alone or HA environment. If log files are already present in the target directory, it will try reuse them, if they are really consistent with those on the server. Extant log files that are no longer part of the current backup file set are deleted or are renamed, depending on how the backup operation was configured.

Renamed backup files have the following syntax: NNNNNNNN.bup.backup number where the backup number is the number associated with the backup attempt, rather than with an individual file. That is, the backup number is increased by one each time a backup is repeated in the same directory and log files actually needed to be renamed.

The implementation tries to be resilient in the face of network failures and minimizes the amount of work that might need to be done if the client or server were to fail and had to be restarted. Users of this API must be careful to ensure that the execute() completes successfully before accessing the environment. The user fails to do this, the InsufficientLogException will be thrown again when the user attempts to open the environment. This safeguard is implemented using the RestoreMarker mechanism.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	NetworkBackup.DigestException Exception indicating that the digest sent by the server did not match the digest computed by the client, that is, the log file was corrupted during transit.
static class	NetworkBackup.InsufficientVLSNRangeException Exception indicating that the server vlsn range did not cover the VLSN of interest.
static class	NetworkBackup.LoadThresholdExceededException
static class	NetworkBackup.RejectedServerException Exception indicating that the server could not be used for the restore.

Constructor Summary

Constructors

Constructor and Description
NetworkBackup(InetSocketAddress serverSocket, File envDir, NameIdPair clientNameId, boolean retainLogfiles, FileManager fileManager, LogManager logManager, DataChannelFactory channelFactory) Convenience overloading.
NetworkBackup(InetSocketAddress serverSocket, int receiveBufferSize, File envDir, NameIdPair clientNameId, boolean retainLogfiles, int serverLoadThreshold, VLSN minVLSN, RepImpl repImpl, FileManager fileManager, LogManager logManager, DataChannelFactory channelFactory, Properties exceptionProperties) Creates a configured backup instance which when executed will backup the files to the environment directory.

Method Summary

Modifier and Type	Method and Description
String[]	execute() Execute the backup.
protected void	getFile(File file) Requests and obtains the specific log file from the server.
NetworkBackupStats	getStats() Returns statistics associated with the NetworkBackup execution.
void	setInterruptHook(TestHook<File> hook)
void	setTestBarrier(CyclicBarrier testBarrier)

Methods inherited from class java.lang.Object

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

Constructor Detail

NetworkBackup

public NetworkBackup(InetSocketAddress serverSocket,
                     int receiveBufferSize,
                     File envDir,
                     NameIdPair clientNameId,
                     boolean retainLogfiles,
                     int serverLoadThreshold,
                     VLSN minVLSN,
                     RepImpl repImpl,
                     FileManager fileManager,
                     LogManager logManager,
                     DataChannelFactory channelFactory,
                     Properties exceptionProperties)
              throws IllegalArgumentException

Creates a configured backup instance which when executed will backup the files to the environment directory.

Parameters:

serverSocket - the socket on which to contact the server

receiveBufferSize - the receive buffer size to be associated with the socket used for the log file transfers.

envDir - the directory in which to place the log files

clientNameId - the id used to identify this client

retainLogfiles - determines whether obsolete log files should be retained by renaming them, instead of deleting them.

serverLoadThreshold - only backup from this server if it has fewer than this number of feeders active.

repImpl - is passed in as a distinct field from the log manager and file manager because it is used only for logging and environment invalidation. A network backup may be invoked by unit tests without an enclosing environment.

minVLSN - the VLSN that should be covered by the server. It ensures that the log files are sufficiently current for this client's needs.

Throws:

IllegalArgumentException - if the environment directory is not valid. When used internally, this should be caught appropriately.

NetworkBackup

public NetworkBackup(InetSocketAddress serverSocket,
                     File envDir,
                     NameIdPair clientNameId,
                     boolean retainLogfiles,
                     FileManager fileManager,
                     LogManager logManager,
                     DataChannelFactory channelFactory)
              throws DatabaseException

Convenience overloading.

Throws:

DatabaseException

See Also:

NetworkBackup(InetSocketAddress, int, File, NameIdPair, boolean, int, VLSN, RepImpl, FileManager, LogManager, DataChannelFactory, Properties)

Method Detail

getStats

public NetworkBackupStats getStats()

Returns statistics associated with the NetworkBackup execution.

execute

public String[] execute()
                 throws IOException,
                        DatabaseException,
                        ServiceDispatcher.ServiceConnectFailedException,
                        NetworkBackup.LoadThresholdExceededException,
                        NetworkBackup.InsufficientVLSNRangeException,
                        RestoreMarker.FileCreationException

Execute the backup.

Throws:

ServiceDispatcher.ServiceConnectFailedException

NetworkBackup.LoadThresholdExceededException

NetworkBackup.InsufficientVLSNRangeException

IOException

DatabaseException

RestoreMarker.FileCreationException

getFile

protected void getFile(File file)
                throws IOException,
                       BinaryProtocol.ProtocolException,
                       NetworkBackup.DigestException,
                       RestoreMarker.FileCreationException

Requests and obtains the specific log file from the server. The file is first created under a name with the .tmp suffix and is renamed to its true name only after its digest has been verified. This method is protected to facilitate error testing.

Throws:

IOException

BinaryProtocol.ProtocolException

NetworkBackup.DigestException

RestoreMarker.FileCreationException

setTestBarrier

public void setTestBarrier(CyclicBarrier testBarrier)

setInterruptHook

public void setInterruptHook(TestHook<File> hook)