com.hazelcast.config

Class QuorumConfig

java.lang.Object

com.hazelcast.config.QuorumConfig

All Implemented Interfaces:

DataSerializable, IdentifiedDataSerializable

public class QuorumConfig
extends Object
implements IdentifiedDataSerializable

Configuration for cluster quorum, a means to protect consistency of data from network partitions. In this context, quorum does not refer to an implementation of a consensus protocol, it refers to the count of members in the cluster required for an operation to succeed.

Since Hazelcast 3.5, the default built-in quorum implementation keeps track of the number of members in the cluster, as determined by Hazelcast's cluster membership management.

Since Hazelcast 3.10, two additional built-in quorum implementations, decoupled from the existing cluster membership management, are provided:

• Probabilistic quorum: in this mode, member heartbeats are tracked and an adaptive failure detector determines for each member the suspicion level. Additionally, when the Hazelcast member is configured with the ICMP ping failure detector enabled and operating in parallel mode, ping information is also used to detect member failures early.

  To create a QuorumConfig for probabilistic quorum, use newProbabilisticQuorumConfigBuilder(String, int) to configure and build the QuorumConfig.

• Recently-active quorum: in this mode, for a member to be considered present for quorum, a heartbeat must be received within the configured time-window since now. Additionally, when the Hazelcast member is configured with the ICMP ping failure detector enabled and operating in parallel mode, ping information is also used to detect member failures early.

  To create a QuorumConfig for recently-active quorum, use newRecentlyActiveQuorumConfigBuilder(String, int, int) to configure and build the QuorumConfig.

See Also:

QuorumFunction, ProbabilisticQuorumFunction, RecentlyActiveQuorumFunction

Constructor Summary

Constructors

Constructor and Description
QuorumConfig()
QuorumConfig(QuorumConfig quorumConfig)
QuorumConfig(String name, boolean enabled)
QuorumConfig(String name, boolean enabled, int size)

Method Summary

Modifier and Type	Method and Description
QuorumConfig	addListenerConfig(QuorumListenerConfig listenerConfig)
int	getFactoryId() Returns DataSerializableFactory factory ID for this class.
int	getId() Returns type identifier for this class.
List<QuorumListenerConfig>	getListenerConfigs()
String	getName()
String	getQuorumFunctionClassName()
QuorumFunction	getQuorumFunctionImplementation()
int	getSize()
QuorumType	getType()
boolean	isEnabled()
static ProbabilisticQuorumConfigBuilder	newProbabilisticQuorumConfigBuilder(String name, int size) Returns a builder for QuorumConfig with the given name using a probabilistic quorum function, for the given quorum size that is enabled by default.
static RecentlyActiveQuorumConfigBuilder	newRecentlyActiveQuorumConfigBuilder(String name, int size, int toleranceMillis) Returns a builder for a QuorumConfig with the given name using a recently-active quorum function for the given quorum size that is enabled by default.
void	readData(ObjectDataInput in) Reads fields from the input stream
QuorumConfig	setEnabled(boolean enabled)
QuorumConfig	setListenerConfigs(List<QuorumListenerConfig> listenerConfigs)
QuorumConfig	setName(String name)
QuorumConfig	setQuorumFunctionClassName(String quorumFunctionClassName)
QuorumConfig	setQuorumFunctionImplementation(QuorumFunction quorumFunctionImplementation)
QuorumConfig	setSize(int size)
QuorumConfig	setType(QuorumType type)
String	toString()
void	writeData(ObjectDataOutput out) Writes object fields to output stream

Methods inherited from class java.lang.Object

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

Constructor Detail

QuorumConfig

public QuorumConfig()

QuorumConfig

public QuorumConfig(String name,
                    boolean enabled)

QuorumConfig

public QuorumConfig(String name,
                    boolean enabled,
                    int size)

QuorumConfig

public QuorumConfig(QuorumConfig quorumConfig)

Method Detail

getName

public String getName()

setName

public QuorumConfig setName(String name)

isEnabled

public boolean isEnabled()

setEnabled

public QuorumConfig setEnabled(boolean enabled)

getSize

public int getSize()

setSize

public QuorumConfig setSize(int size)

getType

public QuorumType getType()

setType

public QuorumConfig setType(QuorumType type)

getListenerConfigs

public List<QuorumListenerConfig> getListenerConfigs()

setListenerConfigs

public QuorumConfig setListenerConfigs(List<QuorumListenerConfig> listenerConfigs)

addListenerConfig

public QuorumConfig addListenerConfig(QuorumListenerConfig listenerConfig)

getQuorumFunctionClassName

public String getQuorumFunctionClassName()

setQuorumFunctionClassName

public QuorumConfig setQuorumFunctionClassName(String quorumFunctionClassName)

getQuorumFunctionImplementation

public QuorumFunction getQuorumFunctionImplementation()

setQuorumFunctionImplementation

public QuorumConfig setQuorumFunctionImplementation(QuorumFunction quorumFunctionImplementation)

toString

public String toString()

Overrides:

toString in class Object

getFactoryId

public int getFactoryId()

Description copied from interface: IdentifiedDataSerializable

Returns DataSerializableFactory factory ID for this class.

Specified by:

getFactoryId in interface IdentifiedDataSerializable

Returns:

factory ID

getId

public int getId()

Description copied from interface: IdentifiedDataSerializable

Returns type identifier for this class. It should be unique per DataSerializableFactory.

Specified by:

getId in interface IdentifiedDataSerializable

Returns:

type ID

writeData

public void writeData(ObjectDataOutput out)
               throws IOException

Description copied from interface: DataSerializable

Writes object fields to output stream

Specified by:

writeData in interface DataSerializable

Parameters:

out - output

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.

readData

public void readData(ObjectDataInput in)
              throws IOException

Description copied from interface: DataSerializable

Reads fields from the input stream

Specified by:

readData in interface DataSerializable

Parameters:

in - input

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the input stream has been closed.

newProbabilisticQuorumConfigBuilder

public static ProbabilisticQuorumConfigBuilder newProbabilisticQuorumConfigBuilder(String name,
                                                                                   int size)

Returns a builder for QuorumConfig with the given name using a probabilistic quorum function, for the given quorum size that is enabled by default.

Parameters:

name - the quorum's name

size - minimum count of members for quorum to be considered present

See Also:

ProbabilisticQuorumFunction

newRecentlyActiveQuorumConfigBuilder

public static RecentlyActiveQuorumConfigBuilder newRecentlyActiveQuorumConfigBuilder(String name,
                                                                                     int size,
                                                                                     int toleranceMillis)

Returns a builder for a QuorumConfig with the given name using a recently-active quorum function for the given quorum size that is enabled by default.

Parameters:

name - the quorum's name

size - minimum count of members for quorum to be considered present

toleranceMillis - maximum amount of milliseconds that may have passed since last heartbeat was received for a member to be considered present for quorum.

See Also:

RecentlyActiveQuorumFunction