Package org.apache.jackrabbit.oak.plugins.document.mongo

Class ReplicaSetStatus

java.lang.Object

org.apache.jackrabbit.oak.plugins.document.mongo.ReplicaSetStatus

All Implemented Interfaces:

com.mongodb.event.ServerMonitorListener, EventListener

public class ReplicaSetStatus
extends Object
implements com.mongodb.event.ServerMonitorListener

Keeps track of the status of a replica set based on information provided by heartbeat events. This status provides a replica set lag estimate, which can be used to decide whether secondaries are sufficiently up-to-date and read operations can be sent to a secondary. This is particularly useful when causal consistent client sessions are used with the MongoDB Java driver. Read operations shouldn't be sent to a secondary when it lags too much behind, otherwise the read operation will block until it was able to catch up.

Field Summary

Fields

Modifier and Type	Field	Description
static final long	UNKNOWN_LAG

Constructor Summary

Constructors

Constructor	Description
ReplicaSetStatus()

Method Summary

Modifier and Type	Method	Description
long	getLagEstimate()
void	serverHeartbeatSucceeded(com.mongodb.event.ServerHeartbeatSucceededEvent event)

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.mongodb.event.ServerMonitorListener

serverHearbeatStarted, serverHeartbeatFailed

Field Details

UNKNOWN_LAG

public static final long UNKNOWN_LAG

See Also:

• Constant Field Values

Constructor Details

ReplicaSetStatus

public ReplicaSetStatus()

Method Details

serverHeartbeatSucceeded

public void serverHeartbeatSucceeded(com.mongodb.event.ServerHeartbeatSucceededEvent event)

Specified by:

serverHeartbeatSucceeded in interface com.mongodb.event.ServerMonitorListener

getLagEstimate

public long getLagEstimate()