Package org.apache.curator.x.async.migrations

Class MigrationManager

java.lang.Object

org.apache.curator.x.async.migrations.MigrationManager

public class MigrationManager
extends Object

Manages migrations

Constructor Summary

Constructors

Constructor	Description
MigrationManager(AsyncCuratorFramework client, String lockPath, String metaDataPath, Executor executor, Duration lockMax)

Method Summary

Modifier and Type	Method	Description
protected List<Migration>	filter(MigrationSet set, List<byte[]> operationHashesInOrder)	Can be overridden to change how the comparison to previous migrations is done.
CompletionStage<Void>	migrate(MigrationSet set)	Process the given migration set

Methods inherited from class java.lang.Object

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

Constructor Details

MigrationManager

public MigrationManager(AsyncCuratorFramework client,
 String lockPath,
 String metaDataPath,
 Executor executor,
 Duration lockMax)

Parameters:

client - the curator client

lockPath - base path for locks used by the manager

metaDataPath - base path to store the meta data

executor - the executor to use

lockMax - max time to wait for locks

Method Details

migrate

public CompletionStage<Void> migrate(MigrationSet set)

Process the given migration set

Parameters:

set - the set

Returns:

completion stage. If there is a migration-specific error, the stage will be completed exceptionally with MigrationException.

filter

protected List<Migration> filter(MigrationSet set,
 List<byte[]> operationHashesInOrder)
                          throws MigrationException

Can be overridden to change how the comparison to previous migrations is done. The default version ensures that the meta data from previous migrations matches the current migration set exactly (by order and version). If there is a mismatch, MigrationException is thrown.

Parameters:

set - the migration set being applied

operationHashesInOrder - previous operation hashes (may be empty)

Returns:

the list of actual migrations to perform. The filter can return any value here or an empty list.

Throws:

MigrationException - errors