[[["わかりやすい","easyToUnderstand","thumb-up"],["問題の解決に役立った","solvedMyProblem","thumb-up"],["その他","otherUp","thumb-up"]],[["わかりにくい","hardToUnderstand","thumb-down"],["情報またはサンプルコードが不正確","incorrectInformationOrSampleCode","thumb-down"],["必要な情報 / サンプルがない","missingTheInformationSamplesINeed","thumb-down"],["翻訳に関する問題","translationIssue","thumb-down"],["その他","otherDown","thumb-down"]],["最終更新日 2025-09-04 UTC。"],[[["\u003cp\u003eUse the Apache Beam Bigtable I/O connector to read data from Bigtable to Dataflow, considering Google-provided Dataflow templates as an alternative depending on your specific use case.\u003c/p\u003e\n"],["\u003cp\u003eParallelism in reading Bigtable data is governed by the number of nodes in the Bigtable cluster, with each node managing key ranges.\u003c/p\u003e\n"],["\u003cp\u003ePerformance metrics for Bigtable read operations on one \u003ccode\u003ee2-standard2\u003c/code\u003e worker using Apache Beam SDK 2.48.0 for Java, show a throughput of 180 MBps or 170,000 elements per second for 100M records, 1 kB, and 1 column, noting that real-world pipeline performance may vary.\u003c/p\u003e\n"],["\u003cp\u003eFor new pipelines, use the \u003ccode\u003eBigtableIO\u003c/code\u003e connector instead of \u003ccode\u003eCloudBigtableIO\u003c/code\u003e, and create separate app profiles for each pipeline type for better traffic differentiation and tracking.\u003c/p\u003e\n"],["\u003cp\u003eBest practices for pipeline optimization include monitoring Bigtable node resources, adjusting timeouts as needed, considering Bigtable autoscaling or resizing, and potentially using replication to separate batch and streaming pipelines for improved performance.\u003c/p\u003e\n"]]],[],null,["# Read from Bigtable to Dataflow\n\nTo read data from Bigtable to Dataflow, use the\nApache Beam [Bigtable I/O connector](https://beam.apache.org/releases/javadoc/current/org/apache/beam/sdk/io/gcp/bigtable/package-summary.html).\n| **Note:** Depending on your scenario, consider using one of the [Google-provided Dataflow templates](/dataflow/docs/guides/templates/provided-templates). Several of these read from Bigtable.\n\nParallelism\n-----------\n\nParallelism is controlled by the number of\n[nodes](/bigtable/docs/instances-clusters-nodes#nodes) in the\nBigtable cluster. Each node manages one or more key ranges,\nalthough key ranges can move between nodes as part of\n[load balancing](/bigtable/docs/overview#load-balancing). For more information,\nsee [Reads and performance](/bigtable/docs/reads#performance) in the\nBigtable documentation.\n\nYou are charged for the number of nodes in your instance's clusters. See\n[Bigtable pricing](/bigtable/pricing).\n\nPerformance\n-----------\n\nThe following table shows performance metrics for Bigtable read\noperations. The workloads were run on one `e2-standard2` worker, using the\nApache Beam SDK 2.48.0 for Java. They did not use Runner v2.\n\n\nThese metrics are based on simple batch pipelines. They are intended to compare performance\nbetween I/O connectors, and are not necessarily representative of real-world pipelines.\nDataflow pipeline performance is complex, and is a function of VM type, the data\nbeing processed, the performance of external sources and sinks, and user code. Metrics are based\non running the Java SDK, and aren't representative of the performance characteristics of other\nlanguage SDKs. For more information, see [Beam IO\nPerformance](https://beam.apache.org/performance/).\n\n\u003cbr /\u003e\n\nBest practices\n--------------\n\n- For new pipelines, use the [`BigtableIO`](https://beam.apache.org/releases/javadoc/current/org/apache/beam/sdk/io/gcp/bigtable/BigtableIO.html) connector, not\n `CloudBigtableIO`.\n\n- Create separate [app profiles](/bigtable/docs/app-profiles) for each type of\n pipeline. App profiles enable better metrics for differentiating traffic\n between pipelines, both for support and for tracking usage.\n\n- Monitor the Bigtable nodes. If you experience performance\n bottlenecks, check whether resources such as CPU utilization are constrained\n within Bigtable. For more information, see\n [Monitoring](/bigtable/docs/monitoring-instance).\n\n- In general, the default timeouts are well tuned for most pipelines. If a\n streaming pipeline appears to get stuck reading from Bigtable,\n try calling [`withAttemptTimeout`](https://beam.apache.org/releases/javadoc/current/org/apache/beam/sdk/io/gcp/bigtable/BigtableIO.Read.html#withAttemptTimeout-org.joda.time.Duration-) to adjust the attempt\n timeout.\n\n- Consider enabling\n [Bigtable autoscaling](/bigtable/docs/autoscaling), or resize\n the Bigtable cluster to scale with the size of your\n Dataflow jobs.\n\n- Consider setting\n [`maxNumWorkers`](/dataflow/docs/reference/pipeline-options#resource_utilization)\n on the Dataflow job to limit load on the\n Bigtable cluster.\n\n- If significant processing is done on a Bigtable element before\n a shuffle, calls to Bigtable might time out. In that case, you\n can call [`withMaxBufferElementCount`](https://beam.apache.org/releases/javadoc/current/org/apache/beam/sdk/io/gcp/bigtable/BigtableIO.Read.html#withMaxBufferElementCount-java.lang.Integer-) to buffer\n elements. This method converts the read operation from streaming to paginated,\n which avoids the issue.\n\n- If you use a single Bigtable cluster for both streaming and\n batch pipelines, and the performance degrades on the Bigtable\n side, consider setting up replication on the cluster. Then separate the batch\n and streaming pipelines, so that they read from different replicas. For more\n information, see [Replication overview](/bigtable/docs/replication-overview).\n\nWhat's next\n-----------\n\n- Read the [Bigtable I/O connector](https://beam.apache.org/releases/javadoc/current/org/apache/beam/sdk/io/gcp/bigtable/package-summary.html) documentation.\n- See the list of [Google-provided templates](/dataflow/docs/guides/templates/provided-templates)."]]
