org.apache.beam.sdk.io.gcp.spanner.changestreams.cache

Class AsyncWatermarkCache

java.lang.Object

org.apache.beam.sdk.io.gcp.spanner.changestreams.cache.AsyncWatermarkCache

All Implemented Interfaces:

WatermarkCache

public class AsyncWatermarkCache
extends java.lang.Object
implements WatermarkCache

Asynchronously compute the earliest partition watermark and stores it in memory. The value will be recomputed periodically, as configured by the refresh rate.

On every period, we will call PartitionMetadataDao.getUnfinishedMinWatermark() to refresh the value.

Constructor Summary

Constructors

Constructor and Description
AsyncWatermarkCache(PartitionMetadataDao dao, Duration refreshRate)

Method Summary

Modifier and Type	Method and Description
com.google.cloud.Timestamp	getUnfinishedMinWatermark() Fetches the earliest partition watermark from the partition metadata table that is not in a PartitionMetadata.State.FINISHED state.

Methods inherited from class java.lang.Object

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

Constructor Detail

AsyncWatermarkCache

public AsyncWatermarkCache(PartitionMetadataDao dao,
                           Duration refreshRate)

Method Detail

getUnfinishedMinWatermark

@Nullable
public com.google.cloud.Timestamp getUnfinishedMinWatermark()

Description copied from interface: WatermarkCache

Fetches the earliest partition watermark from the partition metadata table that is not in a PartitionMetadata.State.FINISHED state.

Specified by:

getUnfinishedMinWatermark in interface WatermarkCache

Returns:

the earliest partition watermark which is not in a PartitionMetadata.State.FINISHED state.