software.amazon.kinesis.worker.metricstats.delegate

Class LeaseTableWorkerMetricStatsDAODelegate

java.lang.Object

software.amazon.kinesis.worker.metricstats.delegate.WorkerMetricStatsDAODelegate<WorkerMetricStats.LeaseTableWorkerMetricStats>

software.amazon.kinesis.worker.metricstats.delegate.LeaseTableWorkerMetricStatsDAODelegate

public class LeaseTableWorkerMetricStatsDAODelegate
extends WorkerMetricStatsDAODelegate<WorkerMetricStats.LeaseTableWorkerMetricStats>

Delegate for WorkerMetricStats stored in the unified lease table.

The lease table uses leaseKey as its partition key attribute name, whereas the legacy dedicated table uses wid. This delegate uses the WorkerMetricStats.LeaseTableWorkerMetricStats inner subclass which overrides the partition key getter to map the workerId field to the leaseKey DDB attribute.

The lease table is always available (created by the lease management layer), so initialize() is a no-op.

Note on scan efficiency: The scan in getAllWorkerMetricStats() uses a filter expression on entityType = WORKER_METRIC_STATS. In the legacy dedicated table this filter is effectively a no-op (all records match). In the lease table, this is not efficient as DynamoDB still reads the entire table and applies the filter server-side. A dedicated entityType GSI would have poor partition distribution for lease entries since all leases share the same entityType value. A better future optimization is to use the leaseOwner GSI (with entityType stored in the leaseOwner attribute position (for non-lease entities) and once the GSI becomes available after the migration state machine completes it can be used for efficient scans which is essentially a query.

Field Summary

Fields inherited from class software.amazon.kinesis.worker.metricstats.delegate.WorkerMetricStatsDAODelegate

log, table, tableName

Constructor Summary

Constructors

Constructor and Description
LeaseTableWorkerMetricStatsDAODelegate(software.amazon.awssdk.services.dynamodb.DynamoDbAsyncClient dynamoDbAsyncClient, String leaseTableName, Long workerMetricsReporterFrequencyMillis)

Method Summary

Modifier and Type	Method and Description
List<WorkerMetricStats>	getAllWorkerMetricStats() Retrieve all worker metric stats entries from the backing table, filtered by entityType = WORKER_METRIC_STATS.
void	initialize() Initialize the delegate.
protected WorkerMetricStats.LeaseTableWorkerMetricStats	toEntity(WorkerMetricStats workerMetrics) Convert a base WorkerMetricStats into a WorkerMetricStats.LeaseTableWorkerMetricStats so the Enhanced Client maps workerId to the leaseKey attribute.
void	updateMetrics(WorkerMetricStats workerMetrics) Update (or create) the worker metric stats for a given worker.

Methods inherited from class software.amazon.kinesis.worker.metricstats.delegate.WorkerMetricStatsDAODelegate

deleteMetrics, getDynamoDbAsyncClient, getTableName

Methods inherited from class java.lang.Object

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

Constructor Detail

LeaseTableWorkerMetricStatsDAODelegate

public LeaseTableWorkerMetricStatsDAODelegate(software.amazon.awssdk.services.dynamodb.DynamoDbAsyncClient dynamoDbAsyncClient,
                                              String leaseTableName,
                                              Long workerMetricsReporterFrequencyMillis)

Method Detail

initialize

public void initialize()
                throws DependencyException

Description copied from class: WorkerMetricStatsDAODelegate

Initialize the delegate. Implementations may check table existence or perform other setup.

Specified by:

initialize in class WorkerMetricStatsDAODelegate<WorkerMetricStats.LeaseTableWorkerMetricStats>

Throws:

DependencyException - if initialization fails due to external dependencies

getAllWorkerMetricStats

public List<WorkerMetricStats> getAllWorkerMetricStats()
                                                throws DependencyException,
                                                       InvalidStateException,
                                                       ProvisionedThroughputException

Retrieve all worker metric stats entries from the backing table, filtered by entityType = WORKER_METRIC_STATS. In the legacy dedicated table this filter is a no-op since all entries should match. In the lease table, this ensures only WorkerMetricStats records are returned (not leases, coordinator state, etc.).

Specified by:

getAllWorkerMetricStats in class WorkerMetricStatsDAODelegate<WorkerMetricStats.LeaseTableWorkerMetricStats>

Returns:

list of all WorkerMetricStats entries

Throws:

DependencyException - if DynamoDB operation fails unexpectedly

InvalidStateException - if the backing table does not exist

ProvisionedThroughputException - if DynamoDB lacks capacity

updateMetrics

public void updateMetrics(WorkerMetricStats workerMetrics)
                   throws DependencyException,
                          InvalidStateException,
                          ProvisionedThroughputException

Description copied from class: WorkerMetricStatsDAODelegate

Update (or create) the worker metric stats for a given worker. Performs an upsert, ignoring null attributes.

Overrides:

updateMetrics in class WorkerMetricStatsDAODelegate<WorkerMetricStats.LeaseTableWorkerMetricStats>

Parameters:

workerMetrics - the worker metrics to persist

Throws:

DependencyException - if DynamoDB operation fails unexpectedly

InvalidStateException - if the backing table does not exist

ProvisionedThroughputException - if DynamoDB lacks capacity

toEntity

protected WorkerMetricStats.LeaseTableWorkerMetricStats toEntity(WorkerMetricStats workerMetrics)

Convert a base WorkerMetricStats into a WorkerMetricStats.LeaseTableWorkerMetricStats so the Enhanced Client maps workerId to the leaseKey attribute.

Specified by:

toEntity in class WorkerMetricStatsDAODelegate<WorkerMetricStats.LeaseTableWorkerMetricStats>