software.amazon.kinesis.coordinator.migration

Enum ClientVersion

java.lang.Object

java.lang.Enum<ClientVersion>

software.amazon.kinesis.coordinator.migration.ClientVersion

All Implemented Interfaces:

Serializable, Comparable<ClientVersion>

public enum ClientVersion
extends Enum<ClientVersion>

ClientVersion support during upgrade from KCLv2.x to KCLv3.x This enum is persisted in storage, so any changes to it needs to be backward compatible. Reorganizing the values is not backward compatible, also if versions are removed, the corresponding enum value cannot be reused without backward compatibility considerations.

Enum Constant Summary

Enum Constants

Enum Constant and Description
CLIENT_VERSION_2X This version is used during rollback from CLIENT_VERSION_UPGRADE_FROM_2X or CLIENT_VERSION_3X_WITH_ROLLBACK, which can only be initiated using a KCL migration tool, when customer wants to revert to KCLv2.x functionality.
CLIENT_VERSION_3X A new application starting KCLv3.x or an upgraded application from KCLv2.x after upgrade is successful can use this version to default all KCLv3.x algorithms without any monitor to rollback.
CLIENT_VERSION_3X_WITH_ROLLBACK When workers are operating in CLIENT_VERSION_UPGRADE_FROM_2X and when worker fleet is determined to be KCLv3.x ready (when lease table GSI is active and worker-metrics are being emitted by all lease owners) then the leader will initiate the switch to KCLv3.x algorithms for leader election and lease assignment, by using this version and persisting it in the MigrationState that allows all worker hosts to also flip to KCLv3.x functionality.
CLIENT_VERSION_INIT This is a transient start state version used during initialization of the Migration State Machine.
CLIENT_VERSION_UPGRADE_FROM_2X This version is used during the upgrade of an application from KCLv2.x to KCLv3.x, in this version KCL workers will emit WorkerMetricStats and run KCLv2.x algorithms for leader election and lease assignment.

Method Summary

Modifier and Type	Method and Description
static ClientVersion	valueOf(String name) Returns the enum constant of this type with the specified name.
static ClientVersion[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

CLIENT_VERSION_INIT

public static final ClientVersion CLIENT_VERSION_INIT

This is a transient start state version used during initialization of the Migration State Machine.

CLIENT_VERSION_UPGRADE_FROM_2X

public static final ClientVersion CLIENT_VERSION_UPGRADE_FROM_2X

This version is used during the upgrade of an application from KCLv2.x to KCLv3.x, in this version KCL workers will emit WorkerMetricStats and run KCLv2.x algorithms for leader election and lease assignment. KCL will also monitor for upgrade to KCLv3.x readiness of the worker fleet.

CLIENT_VERSION_2X

public static final ClientVersion CLIENT_VERSION_2X

This version is used during rollback from CLIENT_VERSION_UPGRADE_FROM_2X or CLIENT_VERSION_3X_WITH_ROLLBACK, which can only be initiated using a KCL migration tool, when customer wants to revert to KCLv2.x functionality. In this version, KCL will not emit WorkerMetricStats and run KCLv2.x algorithms for leader election and lease assignment. In this version, KCL will monitor for roll-forward scenario where client version is updated to CLIENT_VERSION_UPGRADE_FROM_2X using the migration tool.

CLIENT_VERSION_3X_WITH_ROLLBACK

public static final ClientVersion CLIENT_VERSION_3X_WITH_ROLLBACK

When workers are operating in CLIENT_VERSION_UPGRADE_FROM_2X and when worker fleet is determined to be KCLv3.x ready (when lease table GSI is active and worker-metrics are being emitted by all lease owners) then the leader will initiate the switch to KCLv3.x algorithms for leader election and lease assignment, by using this version and persisting it in the MigrationState that allows all worker hosts to also flip to KCLv3.x functionality. In this KCL will also monitor for rollback to detect when the customer updates version to CLIENT_VERSION_2X using migration tool, so that it instantly flips back to CLIENT_VERSION_2X.

CLIENT_VERSION_3X

public static final ClientVersion CLIENT_VERSION_3X

A new application starting KCLv3.x or an upgraded application from KCLv2.x after upgrade is successful can use this version to default all KCLv3.x algorithms without any monitor to rollback.

Method Detail

values

public static ClientVersion[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ClientVersion c : ClientVersion.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ClientVersion valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null