com.hazelcast.core

Interface PartitionService

All Known Implementing Classes:

PartitionServiceProxy, PartitionServiceProxy

public interface PartitionService

PartitionService allows you to query Partitions and attach/detach MigrationListeners to listen to partition migration events. The methods on the PartitionService are thread-safe.

See Also:

Partition, MigrationListener, PartitionLostListener

Method Summary

Modifier and Type	Method and Description
String	addMigrationListener(MigrationListener migrationListener) Adds a MigrationListener.
String	addPartitionLostListener(PartitionLostListener partitionLostListener) Adds a PartitionLostListener.
boolean	forceLocalMemberToBeSafe(long timeout, TimeUnit unit) Force the local member to be safe by checking and syncing partitions owned by the local member with at least one of the backups.
Partition	getPartition(Object key) Returns the partition that the given key belongs to.
Set<Partition>	getPartitions() Returns a set containing all the Partitions in the cluster.
boolean	isClusterSafe() Checks whether the cluster is in a safe state.
boolean	isLocalMemberSafe() Checks whether local member is in safe state.
boolean	isMemberSafe(Member member) Checks whether the given member is in safe state.
String	randomPartitionKey() Deprecated.
boolean	removeMigrationListener(String registrationId) Removes a MigrationListener.
boolean	removePartitionLostListener(String registrationId) Removes a PartitionLostListener.

Method Detail

getPartitions

Set<Partition> getPartitions()

Returns a set containing all the Partitions in the cluster.

Returns:

all partitions in the cluster

getPartition

Partition getPartition(Object key)

Returns the partition that the given key belongs to.

Parameters:

key - the given key

Returns:

the partition that the given key belongs to

randomPartitionKey

@Deprecated
String randomPartitionKey()

Deprecated.

Generates a random partition key. This is useful if you want to partition data in the same partition, but you do not care which partition it is going to be.

The returned value will never be null. This method is deprecated since Hazelcast 3.5. If you need a random partition-key, you can use e.g. a random number, random string or UUID for that.

Returns:

the random partition key

addMigrationListener

String addMigrationListener(MigrationListener migrationListener)

Adds a MigrationListener.

The addMigrationListener returns a register ID. This ID is needed to remove the MigrationListener using the removeMigrationListener(String) method.

There is no check for duplicate registrations, so if you register the listener twice, it will get events twice.

Parameters:

migrationListener - the added MigrationListener

Returns:

returns the registration ID for the MigrationListener

Throws:

NullPointerException - if migrationListener is null

UnsupportedOperationException - if this operation isn't supported. For example on the client side it isn't possible to add a MigrationListener

See Also:

removeMigrationListener(String)

removeMigrationListener

boolean removeMigrationListener(String registrationId)

Removes a MigrationListener.

If the same MigrationListener is registered multiple times, it needs to be removed multiple times.

This method can safely be called multiple times for the same registration ID; every subsequent call is just ignored.

Parameters:

registrationId - the registration ID of the listener to remove

Returns:

true if the listener is removed, false otherwise

Throws:

NullPointerException - if registration ID is null

UnsupportedOperationException - if this operation isn't supported, e.g. on the client side it isn't possible to add/remove a MigrationListener

See Also:

addMigrationListener(MigrationListener)

addPartitionLostListener

String addPartitionLostListener(PartitionLostListener partitionLostListener)

Adds a PartitionLostListener.

The addPartitionLostListener returns a registration ID. This ID is needed to remove the PartitionLostListener using the removePartitionLostListener(String) method.

There is no check for duplicate registrations, so if you register the listener twice, it will get events twice. IMPORTANT: Please @see com.hazelcast.partition.PartitionLostListener for weaknesses

Parameters:

partitionLostListener - the added PartitionLostListener

Returns:

returns the registration ID for the PartitionLostListener

Throws:

NullPointerException - if partitionLostListener is null

See Also:

removePartitionLostListener(String)

removePartitionLostListener

boolean removePartitionLostListener(String registrationId)

Removes a PartitionLostListener.

If the same PartitionLostListener is registered multiple times, it needs to be removed multiple times.

This method can safely be called multiple times for the same registration ID; every subsequent call is just ignored.

Parameters:

registrationId - the registration ID of the listener to remove

Returns:

true if the listener is removed, false otherwise

Throws:

NullPointerException - if registration ID is null

See Also:

addPartitionLostListener(PartitionLostListener)

isClusterSafe

boolean isClusterSafe()

Checks whether the cluster is in a safe state.

Safe state means; there are no partitions being migrated and all backups are in sync when this method is called.

Returns:

true if there are no partitions being migrated and all backups are in sync, false otherwise

Since:

3.3

isMemberSafe

boolean isMemberSafe(Member member)

Checks whether the given member is in safe state.

Safe state means; all backups of partitions currently owned by the member are in sync when this method is called.

Parameters:

member - the cluster member to query

Returns:

true if the member is in a safe state, false otherwise

Since:

3.3

isLocalMemberSafe

boolean isLocalMemberSafe()

Checks whether local member is in safe state.

Safe state means; all backups of partitions currently owned by local member are in sync when this method is called.

Since:

3.3

forceLocalMemberToBeSafe

boolean forceLocalMemberToBeSafe(long timeout,
                                 TimeUnit unit)

Force the local member to be safe by checking and syncing partitions owned by the local member with at least one of the backups.

Parameters:

timeout - the time limit for checking/syncing with the backup

unit - the unit of time for timeout

Since:

3.3