software.amazon.kinesis.coordinator

Class DynamicMigrationComponentsInitializer

java.lang.Object

software.amazon.kinesis.coordinator.DynamicMigrationComponentsInitializer

@ThreadSafe
public final class DynamicMigrationComponentsInitializer
extends Object

This class is responsible for initializing the KCL components that supports 3-phase upgrade from v2.x to v3.x. During specific versions, it also dynamically switches the functionality to be either vanilla 3.x or 2.x compatible. It is responsible for creating: 1. LeaderDecider 2. LAM 3. WorkerMetricStatsReporter It manages initializing the following components at initialization time 1. workerMetricsDAO and workerMetricsManager 2. leaderDecider 3. MigrationAdaptiveLeaseAssignmentModeProvider It updates the following components dynamically: 1. starts/stops LAM 2. starts/stops WorkerMetricStatsReporter 3. updates LeaseAssignmentMode to either DEFAULT_LEASE_COUNT_BASED_ASSIGNMENT or WORKER_UTILIZATION_AWARE_ASSIGNMENT 4. creates GSI (deletion is done by KclMigrationTool) 5. creates WorkerMetricStats table (deletion is done by KclMigrationTool) 6. updates LeaderDecider to either DeterministicShuffleShardSyncLeaderDecider or DynamoDBLockBasedLeaderDecider

Method Summary

Modifier and Type	Method and Description
void	initializeClientVersionFor2x(ClientVersion fromClientVersion) Initialize KCL with components and configuration to run 2x compatible functionality while allowing roll-forward.
void	initializeClientVersionFor3x(ClientVersion fromClientVersion) Initialize KCL with components and configuration to run vanilla 3x functionality.
void	initializeClientVersionFor3xWithRollback(ClientVersion fromClientVersion) Initialize KCL with components and configuration to run vanilla 3x functionality while allowing roll-back to 2x functionality.
void	initializeClientVersionForPhase1() Phase 1 initialization (CLIENT_VERSION_INIT): Purely passive 2.x compatible mode.
void	initializeClientVersionForUpgradeFrom2x(ClientVersion fromClientVersion) Initialize KCL with components and configuration to support upgrade from 2x.

Methods inherited from class java.lang.Object

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

Method Detail

initializeClientVersionForPhase1

public void initializeClientVersionForPhase1()

Phase 1 initialization (CLIENT_VERSION_INIT): Purely passive 2.x compatible mode. No WorkerMetrics collection/reporting, no GSI, no LAM. Uses deterministic leader decider and lease-count-based assignment.

initializeClientVersionForUpgradeFrom2x

public void initializeClientVersionForUpgradeFrom2x(ClientVersion fromClientVersion)
                                             throws DependencyException

Initialize KCL with components and configuration to support upgrade from 2x. This can happen at KCL Worker startup when MigrationStateMachine starts in ClientVersion.CLIENT_VERSION_UPGRADE_FROM_2X. Or Dynamically during roll-forward from ClientVersion.CLIENT_VERSION_2X.

Throws:

DependencyException

initializeClientVersionFor3x

public void initializeClientVersionFor3x(ClientVersion fromClientVersion)
                                  throws DependencyException

Initialize KCL with components and configuration to run vanilla 3x functionality. This can happen at KCL Worker startup when MigrationStateMachine starts in ClientVersion.CLIENT_VERSION_3X, or dynamically during a new deployment when existing workers are in ClientVersion.CLIENT_VERSION_3X_WITH_ROLLBACK. Also used by Phase 3 of migration and by new applications starting directly in 3.x.

Throws:

DependencyException

initializeClientVersionFor2x

public void initializeClientVersionFor2x(ClientVersion fromClientVersion)

Initialize KCL with components and configuration to run 2x compatible functionality while allowing roll-forward. This can happen at KCL Worker startup when MigrationStateMachine starts in ClientVersion.CLIENT_VERSION_2X (after a rollback) Or Dynamically during rollback from CLIENT_VERSION_UPGRADE_FROM_2X or CLIENT_VERSION_3X_WITH_ROLLBACK.

initializeClientVersionFor3xWithRollback

public void initializeClientVersionFor3xWithRollback(ClientVersion fromClientVersion)
                                              throws DependencyException

Initialize KCL with components and configuration to run vanilla 3x functionality while allowing roll-back to 2x functionality. This can happen at KCL Worker startup when MigrationStateMachine starts in ClientVersion.CLIENT_VERSION_3X_WITH_ROLLBACK (after the flip) Or Dynamically during flip from CLIENT_VERSION_UPGRADE_FROM_2X.

Throws:

DependencyException