software.amazon.kinesis.leases

Interface EntityDAO

All Known Implementing Classes:

DynamoDBLeaseTableDao

public interface EntityDAO

DAO that reads all entity types from the lease table in a single DDB scan. When all entities (Leases, WorkerMetricStats, etc.) are co-located in the lease table, this DAO allows scanning all entities in a single DDB scan and grouping them by their type, avoiding redundant scans.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	EntityDAO.Entity Interface for all entity types stored in the lease table.
static class	EntityDAO.EntityScanList Holds the scan result for a single entity type: the successfully deserialized entities and the partition keys of items that failed deserialization.

Method Summary

Modifier and Type	Method and Description
Map<EntityType,EntityDAO.EntityScanList>	scanAllEntities() Scan all entities from the lease table and group them by their EntityType.
Map<EntityType,EntityDAO.EntityScanList>	scanEntities(EntityType... entityTypes) Scan entities from the lease table filtered to only the specified entity types.
default void	shutdown() Shuts down any resources held by this DAO, such as thread pools used for parallel scans.

Method Detail

scanAllEntities

Map<EntityType,EntityDAO.EntityScanList> scanAllEntities()
                                                  throws DependencyException,
                                                         InvalidStateException,
                                                         ProvisionedThroughputException

Scan all entities from the lease table and group them by their EntityType. Records without an entityType attribute are treated as EntityType.LEASE.

Returns:

map of entity type to EntityDAO.EntityScanList containing entities and deserialization failures

Throws:

DependencyException - if DynamoDB scan fails in an unexpected way

InvalidStateException - if the table does not exist

ProvisionedThroughputException - if DynamoDB scan fails due to lack of capacity

scanEntities

Map<EntityType,EntityDAO.EntityScanList> scanEntities(EntityType... entityTypes)
                                               throws DependencyException,
                                                      InvalidStateException,
                                                      ProvisionedThroughputException

Scan entities from the lease table filtered to only the specified entity types. This allows callers to request only the entity types they need (e.g., LEASE and WORKER_METRIC_STATS) and ignore others.

Parameters:

entityTypes - the set of entity types to include in the result

Returns:

map of requested entity types to EntityDAO.EntityScanList containing entities and deserialization failures per type

Throws:

DependencyException - if DynamoDB scan fails in an unexpected way

InvalidStateException - if the table does not exist

ProvisionedThroughputException - if DynamoDB scan fails due to lack of capacity

shutdown

default void shutdown()

Shuts down any resources held by this DAO, such as thread pools used for parallel scans. This method is idempotent.