software.amazon.kinesis.coordinator

Class MigrationAdaptiveLeaseAssignmentModeProvider

java.lang.Object

software.amazon.kinesis.coordinator.MigrationAdaptiveLeaseAssignmentModeProvider

@ThreadSafe
public final class MigrationAdaptiveLeaseAssignmentModeProvider
extends Object

Provides the lease assignment mode KCL must operate in during migration from 2.x to 3.x. KCL v2.x lease assignment is based on distributed-worker-stealing algorithm which balances lease count across workers. KCL v3.x lease assignment is based on a centralized-lease-assignment algorithm which balances resource utilization metrics(e.g. CPU utilization) across workers. For a new application starting in KCL v3.x, there is no migration needed, so KCL will initialize with the lease assignment mode accordingly, and it will not change dynamically. During upgrade from 2.x to 3.x, KCL library needs an ability to start in v2.x assignment mode but dynamically change to v3.x assignment. In this case, both 2.x and 3.x lease assignment will be running but one of them will be a no-op based on the mode. The methods and internal state is guarded for concurrent access to allow both lease assignment algorithms to access the state concurrently while it could be dynamically updated.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MigrationAdaptiveLeaseAssignmentModeProvider.LeaseAssignmentMode

Constructor Summary

Constructors

Constructor and Description
MigrationAdaptiveLeaseAssignmentModeProvider()

Method Summary

Modifier and Type	Method and Description
boolean	dynamicModeChangeSupportNeeded() Specify whether both lease assignment algorithms should be initialized to support dynamically changing lease mode.
MigrationAdaptiveLeaseAssignmentModeProvider.LeaseAssignmentMode	getLeaseAssignmentMode() Provide the current lease assignment mode in which KCL should perform lease assignment

Methods inherited from class java.lang.Object

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

Constructor Detail

MigrationAdaptiveLeaseAssignmentModeProvider

public MigrationAdaptiveLeaseAssignmentModeProvider()

Method Detail

dynamicModeChangeSupportNeeded

public boolean dynamicModeChangeSupportNeeded()

Specify whether both lease assignment algorithms should be initialized to support dynamically changing lease mode.

Returns:

true if lease assignment mode can change dynamically false otherwise.

getLeaseAssignmentMode

public MigrationAdaptiveLeaseAssignmentModeProvider.LeaseAssignmentMode getLeaseAssignmentMode()

Provide the current lease assignment mode in which KCL should perform lease assignment

Returns:

the current lease assignment mode