com.google.cloud.dataflow.sdk.transforms

Class RateLimiting.RateLimitingTransform<I,O>

java.lang.Object

com.google.cloud.dataflow.sdk.transforms.PTransform<PCollection<? extends I>,PCollection<O>>

com.google.cloud.dataflow.sdk.transforms.RateLimiting.RateLimitingTransform<I,O>

Type Parameters:

I - the type of the (main) input elements

O - the type of the (main) output elements

All Implemented Interfaces:

java.io.Serializable

Enclosing class:

RateLimiting

public static class RateLimiting.RateLimitingTransform<I,O>
extends PTransform<PCollection<? extends I>,PCollection<O>>

A PTransform which applies rate limiting to a DoFn.

See Also:

Serialized Form

Field Summary

Fields inherited from class com.google.cloud.dataflow.sdk.transforms.PTransform

name

Constructor Summary

Constructors

Constructor and Description
RateLimiting.RateLimitingTransform(DoFn<I,O> doFn)

Method Summary

Methods

Modifier and Type	Method and Description
PCollection<O>	apply(PCollection<? extends I> input) Applies this PTransform on the given Input, and returns its Output.
RateLimiting.RateLimitingTransform<I,O>	withMaxParallelism(int max) Modifies this RateLimitingTransform, specifying a maximum per-worker parallelism.
RateLimiting.RateLimitingTransform<I,O>	withRateLimit(double maxElementsPerSecond) Modifies this RateLimitingTransform, specifying a maximum per-worker element processing rate.

Methods inherited from class com.google.cloud.dataflow.sdk.transforms.PTransform

finishSpecifying, getCoderRegistry, getDefaultName, getDefaultOutputCoder, getDefaultOutputCoder, getInput, getKindString, getName, getOutput, getPipeline, setName, setPipeline, toString, withName

Methods inherited from class java.lang.Object

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

Constructor Detail

RateLimiting.RateLimitingTransform

public RateLimiting.RateLimitingTransform(DoFn<I,O> doFn)

Method Detail

withRateLimit

public RateLimiting.RateLimitingTransform<I,O> withRateLimit(double maxElementsPerSecond)

Modifies this RateLimitingTransform, specifying a maximum per-worker element processing rate.

A rate of N corresponds to N elements per second. This rate is on a per-worker basis, so the overall rate of the job depends upon the number of workers.

This rate limit may not be reachable unless there is sufficient parallelism.

A rate of <= 0.0 disables rate limiting.

withMaxParallelism

public RateLimiting.RateLimitingTransform<I,O> withMaxParallelism(int max)

Modifies this RateLimitingTransform, specifying a maximum per-worker parallelism.

This determines how many concurrent elements will be processed by the wrapped DoFn.

The desired amount of parallelism depends upon the type of work. For CPU-intensive work, a good starting point is to use the number of cores: Runtime.getRuntime().availableProcessors().

apply

public PCollection<O> apply(PCollection<? extends I> input)

Description copied from class: PTransform

Applies this PTransform on the given Input, and returns its Output.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

The default implementation throws an exception. A derived class must either implement apply, or else each runner must supply a custom implementation via PipelineRunner.apply(com.google.cloud.dataflow.sdk.transforms.PTransform<Input, Output>, Input).

Overrides:

apply in class PTransform<PCollection<? extends I>,PCollection<O>>