Apache Beam

Apache Beam is a unified model for defining both batch and streaming data-parallel processing pipelines, as well as a set of language-specific SDKs for constructing pipelines and Runners for executing them on distributed processing backends, including Apache Flink, Apache Spark, Google Cloud Dataflow and Hazelcast Jet.


Maven Version PyPI version Python coverage Compat Check PyPI Compat Check at master Build python source distribution and wheels Python tests Java tests

Post-commit tests status (on master branch)
Lang SDK Dataflow Flink Samza Spark Twister2
Go Build Status --- Build Status --- Build Status ---
Java Build Status Build Status
Build Status
Build Status
Build Status
Build Status
Build Status
Build Status
Build Status Build Status
Build Status
Build Status
Build Status
Python Build Status
Build Status
Build Status
Build Status
Build Status
Build Status
Build Status
Build Status
--- Build Status ---
XLang Build Status Build Status Build Status --- Build Status ---


Beam provides a general approach to expressing embarrassingly parallel data processing pipelines and supports three categories of users, each of which have relatively disparate backgrounds and needs.

  1. End Users: Writing pipelines with an existing SDK, running it on an existing runner. These users want to focus on writing their application logic and have everything else just work.
  2. SDK Writers: Developing a Beam SDK targeted at a specific user community (Java, Python, Scala, Go, R, graphical, etc). These users are language geeks and would prefer to be shielded from all the details of various runners and their implementations.
  3. Runner Writers: Have an execution environment for distributed processing and would like to support programs written against the Beam Model. Would prefer to be shielded from details of multiple SDKs.
The Beam Model

The model behind Beam evolved from a number of internal Google data processing projects, including MapReduce, FlumeJava, and Millwheel. This model was originally known as the “Dataflow Model”.

To learn more about the Beam Model (though still under the original name of Dataflow), see the World Beyond Batch: Streaming 101 and Streaming 102 posts on O’Reilly’s Radar site, and the VLDB 2015 paper.

The key concepts in the Beam programming model are:

  • PCollection: represents a collection of data, which could be bounded or unbounded in size.
  • PTransform: represents a computation that transforms input PCollections into output PCollections.
  • Pipeline: manages a directed acyclic graph of PTransforms and PCollections that is ready for execution.
  • PipelineRunner: specifies where and how the pipeline should execute.

Beam supports multiple language specific SDKs for writing pipelines against the Beam Model.

Currently, this repository contains SDKs for Java, Python and Go.

Have ideas for new SDKs or DSLs? See the JIRA.


Beam supports executing programs on multiple distributed processing backends through PipelineRunners. Currently, the following PipelineRunners are available:

  • The DirectRunner runs the pipeline on your local machine.
  • The DataflowRunner submits the pipeline to the Google Cloud Dataflow.
  • The FlinkRunner runs the pipeline on an Apache Flink cluster. The code has been donated from dataArtisans/flink-dataflow and is now part of Beam.
  • The SparkRunner runs the pipeline on an Apache Spark cluster. The code has been donated from cloudera/spark-dataflow and is now part of Beam.
  • The JetRunner runs the pipeline on a Hazelcast Jet cluster. The code has been donated from hazelcast/hazelcast-jet and is now part of Beam.
  • The Twister2Runner runs the pipeline on a Twister2 cluster. The code has been donated from DSC-SPIDAL/twister2 and is now part of Beam.

Have ideas for new Runners? See the JIRA.

Getting Started

To learn how to write Beam pipelines, read the Quickstart for [Java, Python, or Go] available on our website.

Contact Us

To get involved in Apache Beam:

Instructions for building and testing Beam itself are in the contribution guide.

More Information

Expand ▾ Collapse ▴


Path Synopsis
sdks/go/cmd/beamctl beamctl is a command line client for the Apache Beam portability services.
sdks/go/cmd/beamctl/cmd Package cmd contains the commands for beamctl.
sdks/go/cmd/specialize specialize is a low-level tool to generate type-specialized code.
sdks/go/cmd/starcgen starcgen is a tool to generate specialized type assertion shims to be used in Apache Beam Go SDK pipelines instead of the default reflection shim.
sdks/go/cmd/symtab Package verifies that functions sym2addr and addr2sym work correctly.
sdks/go/examples/cookbook/tornadoes tornadoes is an example that reads the public samples of weather data from BigQuery, counts the number of tornadoes that occur in each month, and writes the results to BigQuery.
sdks/go/examples/debugging_wordcount debugging_wordcount is an example that verifies word counts in Shakespeare and includes Beam best practices.
sdks/go/examples/forest forest is an example that shows that pipeline construction is normal Go code -- the pipeline "forest" is created recursively and uses a global variable -- and that a pipeline may contain non-connected parts.
sdks/go/examples/minimal_wordcount minimal_wordcount is an example that counts words in Shakespeare.
sdks/go/examples/multiout multiout is a wordcount variation that uses a multi-outout DoFn and writes 2 output files.
sdks/go/examples/readavro readavro is a simple Avro read/write Example This example uses a 500 Byte sample avro file [twitter.avro] download here:
sdks/go/examples/streaming_wordcap streaming_wordcap is a toy streaming pipeline that uses PubSub.
sdks/go/examples/stringsplit An example of using a Splittable DoFn in the Go SDK with a portable runner.
sdks/go/examples/windowed_wordcount windowed_wordcount counts words in text, and can run over either unbounded or bounded input collections.
sdks/go/examples/wordcount wordcount is an example that counts words in Shakespeare and includes Beam best practices.
sdks/go/examples/xlang Package xlang contains functionality for testing cross-language transforms.
sdks/go/examples/xlang/cogroup_by cogroup_by exemplifies using a cross-language cogroup by key transform from a test expansion service.
sdks/go/examples/xlang/combine combine exemplifies using a cross-language combine per key transform from a test expansion service.
sdks/go/examples/xlang/combine_globally combine_globally exemplifies using a cross-language combine global transform from a test expansion service.
sdks/go/examples/xlang/group_by group_by exemplifies using a cross-language group by key transform from a test expansion service.
sdks/go/examples/xlang/multi_input_output multi exemplifies using a cross-language transform with multiple inputs and outputs from a test expansion service.
sdks/go/examples/xlang/partition partition exemplifies using a cross-language partition transform from a test expansion service.
sdks/go/examples/xlang/wordcount wordcount exemplifies using a cross-language Count transform from a test expansion service to count words.
sdks/go/examples/yatzy yatzy is an implementation of that shows that pipeline construction is normal Go code.
sdks/go/pkg/beam Package beam is an implementation of the Apache Beam ( programming model in Go.
sdks/go/pkg/beam/artifact Package artifact contains utilities for staging and retrieving artifacts.
sdks/go/pkg/beam/artifact/gcsproxy Package gcsproxy contains artifact staging and retrieval servers backed by GCS.
sdks/go/pkg/beam/core/funcx Package funcx contains functions and types used to perform type analysis of Beam functions.
sdks/go/pkg/beam/core/graph Package graph is the internal representation of the Beam execution plan.
sdks/go/pkg/beam/core/graph/coder Package coder contains coder representation and utilities.
sdks/go/pkg/beam/core/graph/mtime Package mtime contains a millisecond representation of time.
sdks/go/pkg/beam/core/graph/window Package window contains window representation, windowing strategies and utilities.
sdks/go/pkg/beam/core/metrics Package metrics implements the Beam metrics API, described at Metrics in the Beam model are uniquely identified by a namespace, a name, and the PTransform context in which they are used.
sdks/go/pkg/beam/core/runtime Package runtime contains runtime hooks and utilities for pipeline options and type registration.
sdks/go/pkg/beam/core/runtime/coderx Package coderx contains coders for primitive types that aren't included in the beam model.
sdks/go/pkg/beam/core/runtime/exec Package exec contains runtime plan representation and execution.
sdks/go/pkg/beam/core/runtime/exec/optimized Package optimized contains type-specialized shims for faster execution.
sdks/go/pkg/beam/core/runtime/genx Package genx is a convenience package to better support the code generator.
sdks/go/pkg/beam/core/runtime/graphx Package graphx provides facilities to help with the serialization of pipelines into a serializable graph structure suitable for the worker.
sdks/go/pkg/beam/core/runtime/graphx/schema Package schema contains utility functions for relating Go types and Beam Schemas.
sdks/go/pkg/beam/core/runtime/graphx/v1 Package v1 is a generated protocol buffer package.
sdks/go/pkg/beam/core/runtime/harness Package harness implements the SDK side of the Beam FnAPI.
sdks/go/pkg/beam/core/runtime/harness/init Package init contains the harness initialization code defined by the FnAPI.
sdks/go/pkg/beam/core/runtime/harness/session Package session is a generated protocol buffer package.
sdks/go/pkg/beam/core/runtime/pipelinex Package pipelinex contains utilities for manipulating Beam proto pipelines.
sdks/go/pkg/beam/core/sdf Package contains interfaces used specifically for splittable DoFns.
sdks/go/pkg/beam/core/typex Package typex contains full type representation for PCollections and DoFns, and utilities for type checking.
sdks/go/pkg/beam/core/util/dot Package dot produces DOT graphs from Beam graph representations.
sdks/go/pkg/beam/core/util/hooks Package hooks allows runners to tailor execution of the worker harness.
sdks/go/pkg/beam/core/util/ioutilx Package ioutilx contains additional io utilities.
sdks/go/pkg/beam/core/util/jsonx Package jsonx contains utilities for working with JSON encoded data.
sdks/go/pkg/beam/core/util/protox Package protox contains utilities for working with protobufs.
sdks/go/pkg/beam/core/util/reflectx Package reflectx contains a set of reflection utilities and well-known types.
sdks/go/pkg/beam/core/util/stringx Package stringx contains utilities for working with strings.
sdks/go/pkg/beam/core/util/symtab Package symtab allows reading low-level symbol information from the symbol table.
sdks/go/pkg/beam/internal/errors Package errors contains functionality for creating and wrapping errors with improved formatting compared to the standard Go error functionality.
sdks/go/pkg/beam/io/avroio Package avroio contains transforms for reading and writing avro files.
sdks/go/pkg/beam/io/bigqueryio Package bigqueryio provides transformations and utilities to interact with Google BigQuery.
sdks/go/pkg/beam/io/databaseio Package databaseio provides transformations and utilities to interact with generic database database/sql API.
sdks/go/pkg/beam/io/datastoreio Package datastoreio provides transformations and utilities to interact with Google Datastore.
sdks/go/pkg/beam/io/filesystem Package filesystem contains an extensible file system abstraction.
sdks/go/pkg/beam/io/filesystem/gcs Package gcs contains a Google Cloud Storage (GCS) implementation of the Beam file system.
sdks/go/pkg/beam/io/filesystem/local Package local contains a local file implementation of the Beam file system.
sdks/go/pkg/beam/io/filesystem/memfs Package memfs contains a in-memory Beam filesystem.
sdks/go/pkg/beam/io/pubsubio Package pubsubio provides access to PubSub on Dataflow streaming.
sdks/go/pkg/beam/io/pubsubio/v1 Package v1 is a generated protocol buffer package.
sdks/go/pkg/beam/io/rtrackers/offsetrange Package offsetrange defines a restriction and restriction tracker for offset ranges.
sdks/go/pkg/beam/io/synthetic Package synthetic contains transforms for creating synthetic pipelines.
sdks/go/pkg/beam/io/textio Package textio contains transforms for reading and writing text files.
sdks/go/pkg/beam/log Package log contains a re-targetable context-aware logging system.
sdks/go/pkg/beam/model Package model contains the portable Beam model contracts.
sdks/go/pkg/beam/options/gcpopts Package gcpopts contains shared options for Google Cloud Platform.
sdks/go/pkg/beam/options/jobopts Package jobopts contains shared options for job submission.
sdks/go/pkg/beam/provision Package provision contains utilities for obtaining runtime provision, information -- such as pipeline options.
sdks/go/pkg/beam/runners/dataflow Package dataflow contains the Dataflow runner for submitting pipelines to Google Cloud Dataflow.
sdks/go/pkg/beam/runners/dataflow/dataflowlib Package dataflowlib translates a Beam pipeline model to the Dataflow API job model, for submission to Google Cloud Dataflow.
sdks/go/pkg/beam/runners/direct Package direct contains the direct runner for running single-bundle pipelines in the current process.
sdks/go/pkg/beam/runners/dot Package dot is a Beam runner that "runs" a pipeline by producing a DOT graph of the execution plan.
sdks/go/pkg/beam/runners/flink Package flink contains the Flink runner.
sdks/go/pkg/beam/runners/spark Package spark contains the Spark runner.
sdks/go/pkg/beam/runners/universal Package universal contains a general-purpose runner that can submit jobs to any portable Beam runner.
sdks/go/pkg/beam/runners/universal/extworker Package extworker provides an external worker service and related utilities.
sdks/go/pkg/beam/runners/universal/runnerlib Package runnerlib contains utilities for submitting Go pipelines to a Beam model runner.
sdks/go/pkg/beam/runners/vet Package vet is a Beam runner that "runs" a pipeline by producing generated code to avoid symbol table lookups and reflection in pipeline execution.
sdks/go/pkg/beam/runners/vet/testpipeline Package testpipeline exports small test pipelines for testing the vet runner.
sdks/go/pkg/beam/testing/passert Package passert contains verification transformations for testing pipelines.
sdks/go/pkg/beam/testing/ptest Package ptest contains utilities for pipeline unit testing.
sdks/go/pkg/beam/transforms/filter Package filter contains transformations for removing pipeline elements based on various conditions.
sdks/go/pkg/beam/transforms/stats Package stats contains transforms for statistical processing.
sdks/go/pkg/beam/transforms/top Package top contains transformations for finding the smallest (or largest) N elements based on arbitrary orderings.
sdks/go/pkg/beam/util/errorx Package errorx contains utilities for handling errors.
sdks/go/pkg/beam/util/execx Package execx contains wrappers and utilities for the exec package.
sdks/go/pkg/beam/util/gcsx Package gcsx contains utilities for working with Google Cloud Storage (GCS).
sdks/go/pkg/beam/util/grpcx Package grpcx contains utilities for working with gRPC.
sdks/go/pkg/beam/util/pubsubx Package pubsubx contains utilities for working with Google PubSub.
sdks/go/pkg/beam/util/shimx Package shimx specifies the templates for generating type assertion shims for Apache Beam Go SDK pipelines.
sdks/go/pkg/beam/util/starcgenx Package starcgenx is a Static Analysis Type Assertion shim and Registration Code Generator which provides an extractor to extract types from a package, in order to generate approprate shimsr a package so code can be generated for it.
sdks/go/pkg/beam/util/syscallx Package syscallx provides system call utilities that attempt to hide platform differences.
sdks/go/pkg/beam/x/beamx Package beamx is a convenience package for beam.
sdks/go/pkg/beam/x/debug Package debug contains pipeline components that may help in debugging pipeline issues.
sdks/go/pkg/beam/x/hooks/perf Package perf is to add performance measuring hooks to a runner, such as cpu, heap, or trace profiles.
sdks/go/test/integration The integration driver provides a suite of tests to run against a registered runner.
sdks/go/test/integration/synthetic Package synthetic contains pipelines for testing synthetic steps and sources.
sdks/go/test/integration/wordcount Package wordcount contains transforms for wordcount.
sdks/go/test/regression Package regression contains pipeline regression tests.
sdks/go/test/regression/coders/fromyaml fromyaml generates a resource file from the standard_coders.yaml file for use in these coder regression tests.
sdks/go/test/validatesrunner Package validatesrunner contains Validates Runner tests, which are a type of integration test that execute short pipelines on various runners to validate runner behavior.
sdks/java/container boot is the boot code for the Java SDK harness container.
sdks/python/container boot is the boot code for the Python SDK harness container.