Package com.sleepycat.je.rep

Berkeley DB Java Edition High Availability (JE HA) enables replication of JE environments.

See:
Description

Interface Summary

AppStateMonitor	A mechanism for adding application specific information when asynchronously tracking the state of a running JE HA application.
ReplicationNode	An administrative view of a node in a replication group.
StateChangeListener	An asynchronous mechanism for tracking the State of the replicated environment and choosing how to route database operations.

Class Summary

CommitPointConsistencyPolicy	A consistency policy which ensures that the environment on a Replica node is at least as current as denoted by the specified CommitToken.
NetworkRestore	Obtains log files for a Replica from other members of the replication group.
NetworkRestoreConfig	NetworkRestoreConfig defines the configuration parameters used to configure a NetworkRestore operation.
NoConsistencyRequiredPolicy	A consistency policy that lets a transaction on a replica using this policy proceed regardless of the state of the Replica relative to the Master.
NodeState	The current state of a replication node and the application this node is running in.
ReplicatedEnvironment	A replicated database environment that is a node in a replication group.
ReplicatedEnvironmentStats	Statistics for a replicated environment.
ReplicationConfig	Specifies the immutable attributes of a replicated environment.
ReplicationGroup	An administrative view of the collection of nodes that form the replication group.
ReplicationMutableConfig	Specifies the attributes that may be changed after a ReplicatedEnvironment has been created.
StateChangeEvent	Communicates the state change at a node to the StateChangeListener.
TimeConsistencyPolicy	A consistency policy which describes the amount of time the Replica is allowed to lag the Master.

Enum Summary

NodeType	The different types of nodes that can be in a replication group.
QuorumPolicy	The quorum policy determine the number of nodes that must participate to pick the winner of an election, and therefore the master of the group.
ReplicatedEnvironment.State	The replication node state determines the operations that the application can perform against its replicated environment.
SyncupProgress	Describes the different phases of replication stream syncup that are executed when a replica starts working with a new replication group master.

Exception Summary

DatabasePreemptedException	Thrown when attempting to use a Database handle that was forcibly closed by replication.
GroupShutdownException	Thrown when an attempt is made to access an environment that was shutdown by the Master as a result of a call to ReplicatedEnvironment.shutdownGroup(long, TimeUnit).
InsufficientAcksException	This exception is thrown at the time of a commit in a Master, if the Master could not obtain transaction commit acknowledgments from its Replicas in accordance with the Durability.ReplicaAckPolicy currently in effect.
InsufficientLogException	This exception indicates that the log files constituting the Environment are insufficient and cannot be used as the basis for continuing with the replication stream provided by the current master.
InsufficientReplicasException	Thrown by Environment.beginTransaction(com.sleepycat.je.Transaction, com.sleepycat.je.TransactionConfig) and Transaction.commit() when these operations are initiated at a Master which is not in contact with a quorum of Replicas as determined by the Durability.ReplicaAckPolicy that is in effect for the operation.
LockPreemptedException	Thrown when a lock has been "stolen", or preempted, from a transaction in a replicated environment.
LogOverwriteException	Thrown when one or more log files are modified (overwritten) as the result of a replication operation.
MasterReplicaTransitionException	MasterReplicaTransitionException is thrown in JE replication systems when this environment is a master and must transition to replica state.
MasterStateException	This exception indicates that the application attempted an operation that is not permitted when it is in the Replicator.State.Master state.
MemberNotFoundException	Thrown when an operation requires a replication group member and that member is not present in the replication group.
ReplicaConsistencyException	This exception is thrown by a Replica to indicate it could not meet the consistency requirements as defined by the ReplicaConsistencyPolicy in effect for the transaction, within the allowed timeout period.
ReplicaStateException	This exception indicates that the application attempted an operation that is not permitted when it is in the Replicator.State.Replica state.
ReplicaWriteException	This exception indicates that an update operation was attempted while in the ReplicatedEnvironment.State.REPLICA state.
RestartRequiredException	RestartRequiredException serves as the base class for all exceptions which makes it impossible for HA to proceed without some form of corrective action on the part of the user, followed by a restart of the application.
RollbackException	This asynchronous exception indicates that a new master has been selected, this Replica's log is ahead of the current Master, and in this case, the Replica was unable to rollback without a recovery.
RollbackProhibitedException	This exception may be thrown by a Replica during the replication stream sync-up phase of startup.
StateChangeException	Provides a synchronous mechanism for informing an application about a change in the state of the replication node.
UnknownMasterException	Indicates that the underlying operation requires communication with a Master, but that a Master was not available.

Package com.sleepycat.je.rep Description

Berkeley DB Java Edition High Availability (JE HA) enables replication of JE environments. JE HA is an embedded database management system designed to provide fast, reliable, and scalable data management. A JE environment is replicated across the nodes of a single read/write Master, multiple read only Replica Replication Group. JE HA is used to improve application availability, provide improved read performance, and increase data durability.

Getting Started

The Replication Guide is invaluable for understanding the capabilities of JE HA and how best to design your replicated application.

The Introduction covers terminology, the replication group lifecycle, and the concepts of durability and consistency. Much of the javadoc refers to the topics covered there.

Replication API First Steps explains how to configure and start a replication group.

Transaction Management highlights the tradeoffs that must be considered in a replicated application and provides some use cases.

In addition, the je.rep.quote example package provides three example replication applications.

What the com.sleepycat.je.rep package contains

Replication control

• ReplicatedEnvironment is the main access point to replication.
• ReplicationConfig and ReplicationMutableConfig specify attributes of the replication system.

Administration

• ReplicationNode and ReplicationGroup supply administrative views of the replication system.

Support

• StateChangeListener and StateChangeEvent implement a Listener pattern for tracking changes in the replication system.
• CommitPointConsistencyPolicy, TimeConsistencyPolicy and NoConsistencyPolicy let the user control the read only replica's view of the the replicated data.
• ReplicatedEnviromentStats provide feedback on system execution.

Related Packages

• com.sleepycat.je.rep.monitor lets the application track the replication system in order to do tasks such as load balancing and write request routing.
• com.sleepycat.je.rep.util provides command line and programmatic APIs for administering and starting up a replication system.

Related Documentation

See Also:

Replication Guide, JE HA Examples