Package org.apache.cassandra.schema

Class MigrationCoordinator

java.lang.Object

org.apache.cassandra.schema.MigrationCoordinator

public class MigrationCoordinator
extends Object

Migration coordinator is responsible for tracking schema versions on various nodes and, if needed, synchronize the schema. It performs periodic checks and if there is a schema version mismatch between the current node and the other node, it pulls the schema and applies the changes locally through the callback. In particular the Migration Coordinator keeps track of all schema versions reported from each node in the cluster. As long as a certain version is advertised by some node, it is being tracked. As long as a version is tracked, the migration coordinator tries to fetch it by its periodic job. It works in close cooperation with DefaultSchemaUpdateHandler which is responsible for maintaining local schema metadata stored in SchemaKeyspace.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MAX_OUTSTANDING_VERSION_REQUESTS

Method Summary

Modifier and Type	Method	Description
static void	setUptimeFn(LongSupplier supplier)

Methods inherited from class java.lang.Object

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

Field Details

MAX_OUTSTANDING_VERSION_REQUESTS

public static final int MAX_OUTSTANDING_VERSION_REQUESTS

See Also:

• Constant Field Values

Method Details

setUptimeFn

public static void setUptimeFn(LongSupplier supplier)