THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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Note: Startpoints are removed from StorageLayer at the first checkpoint offset commit. This ensures precedence is with the Startpoint until the next Checkpoint is committed, specifically in situations where the SamzaProcessor restarts before the commit.
If SamzaProcessor have checkpoints disabled (*.samza.reset.offset=true), then Startpoints are removed immediately after being read.
Startpoint Models
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/**
* Startpoint represents a position in a stream partition
*/
public abstract class Startpoint {
private final long creationTimestamp;
/**
* Apply the visitor {@link StartpointVisitor}'s register methods to the instance of this {@link Startpoint}
* class.
* @param systemStreamPartition The {@link SystemStreamPartition} needed to register with the {@link StartpointVisitor}
* @param startpointVisitor The visitor to register with.
*/
public abstract void apply(SystemStreamPartition systemStreamPartition, StartpointVisitor startpointVisitor);
// Full implementation not shown for brevity
}
/**
* A {@link Startpoint} that represents a specific offset in a stream partition.
*/
public final class StartpointSpecific extends Startpoint { ... }
/**
* A {@link Startpoint} that represents a timestamp offset in a stream partition.
*/
public final class StartpointTimestamp extends Startpoint { ... }
/**
* A {@link Startpoint} that represents the earliest offset in a stream partition.
*/
public final class StartpointOldest extends Startpoint { ... }
/**
* A {@link Startpoint} that represents the latest offset in a stream partition.
*/
public final class StartpointUpcoming extends Startpoint { ... }
/**
* A {@link Startpoint} that represents a custom startpoint. This is for systems that have a non-generic option
* for setting offsets. Startpoints are serialized to JSON in the {@link org.apache.samza.metadatastore.MetadataStore}
* and it is recommended to maintain the subclass of this {@link StartpointCustom} as a simple POJO.
*/
public abstract class StartpointCustom extends Startpoint { ... }
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