Fix BigQuery Storage Write API stream count for batch writes

sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.java

@@ -3401,7 +3401,7 @@ public Write<T> withNumFileShards(int numFileShards) {
      * runner determine the sharding at runtime, set this to zero, or {@link #withAutoSharding()}
      * instead.
      *
-     * <p>For batch pipelines, it inserts a redistribute. To not reshufle and keep the pipeline
+     * <p>For batch pipelines, it inserts a redistribute. To not reshuffle and keep the pipeline
      * parallelism as is, set this to zero.
      */
     public Write<T> withNumStorageWriteApiStreams(int numStorageWriteApiStreams) {
@@ -3834,13 +3834,9 @@ && getStorageApiTriggeringFrequency(bqOptions) != null) {
           LOG.warn(
               "Setting the triggering frequency is only applicable to an unbounded PCollection.");
         }
-        if (getStorageApiNumStreams(bqOptions) != 0) {
-          LOG.warn(
-              "Setting the number of Storage API streams is only applicable to an unbounded PCollection.");
-        }
       }
 
-      if (method == Method.STORAGE_API_AT_LEAST_ONCE && getStorageApiNumStreams(bqOptions) != 0) {
+      if (method != Method.STORAGE_WRITE_API && getStorageApiNumStreams(bqOptions) != 0) {
         LOG.warn(
             "Setting a number of Storage API streams is only supported when using STORAGE_WRITE_API");
       }

sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryOptions.java

@@ -102,7 +102,7 @@ public interface BigQueryOptions
   void setUseStorageWriteApiAtLeastOnce(Boolean value);
 
   @Description(
-      "When writing with a streaming pipeline, the BigQueryIO.Write will default to using this number of Storage Write API streams. ")
+      "When writing with STORAGE_WRITE_API, BigQueryIO.Write will default to using this number of Storage Write API streams. ")
   @Default.Integer(0)
   Integer getNumStorageWriteApiStreams();
 

sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/providers/BigQueryStorageWriteApiSchemaTransformProvider.java

@@ -179,11 +179,15 @@ public PCollectionRowTuple expand(PCollectionRowTuple input) {
       PCollection<Row> inputRows = input.getSinglePCollection();
 
       BigQueryIO.Write<Row> write = createStorageWriteApiTransform(inputRows.getSchema());
+      int numStreams = configuration.getNumStreams() == null ? 0 : configuration.getNumStreams();
+
+      if (numStreams > 0) {
+        write = write.withNumStorageWriteApiStreams(numStreams);
+      }
 
       if (inputRows.isBounded() == IsBounded.UNBOUNDED) {
         Long triggeringFrequency = configuration.getTriggeringFrequencySeconds();
         Boolean autoSharding = configuration.getAutoSharding();
-        int numStreams = configuration.getNumStreams() == null ? 0 : configuration.getNumStreams();
 
         boolean useAtLeastOnceSemantics =
             configuration.getUseAtLeastOnceSemantics() != null
@@ -196,10 +200,8 @@ public PCollectionRowTuple expand(PCollectionRowTuple input) {
                       ? DEFAULT_TRIGGERING_FREQUENCY
                       : Duration.standardSeconds(triggeringFrequency));
         }
-        // set num streams if specified, otherwise default to autoSharding
-        if (numStreams > 0) {
-          write = write.withNumStorageWriteApiStreams(numStreams);
-        } else if (autoSharding == null || autoSharding) {
+        // Default to autoSharding for unbounded writes when a fixed stream count is not specified.
+        if (numStreams <= 0 && (autoSharding == null || autoSharding)) {
           write = write.withAutoSharding();
         }
       }

sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/providers/BigQueryWriteConfiguration.java

@@ -152,8 +152,7 @@ public static Builder builder() {
   public abstract Boolean getAutoSharding();
 
   @SchemaFieldDescription(
-      "Specifies the number of write streams that the Storage API sink will use. "
-          + "This parameter is only applicable when writing unbounded data.")
+      "Specifies the number of write streams that the Storage API sink will use.")
   @Nullable
   public abstract Integer getNumStreams();
 

sdks/java/io/google-cloud-platform/src/test/java/org/apache/beam/sdk/io/gcp/bigquery/providers/BigQueryStorageWriteApiSchemaTransformProviderTest.java

@@ -483,6 +483,24 @@ public void testErrorCount() throws Exception {
     }
   }
 
+  @Test
+  public void testNumStreamsAppliesToBoundedStorageApiWrites() {
+    BigQueryWriteConfiguration config =
+        BigQueryWriteConfiguration.builder()
+            .setTable("project:dataset.bounded_fixed_num_streams")
+            .setNumStreams(3)
+            .build();
+
+    runWithConfig(config);
+
+    RunnerApi.Pipeline pipelineProto = PipelineTranslation.toProto(p);
+    boolean hasFixedNumStreamsRedistribute =
+        pipelineProto.getComponents().getTransformsMap().values().stream()
+            .anyMatch(tr -> tr.getUniqueName().contains("ResdistibuteNumShards"));
+    assertTrue(hasFixedNumStreamsRedistribute);
+    p.enableAbandonedNodeEnforcement(false);
+  }
+
   @Test
   public void testManagedChoosesStorageApiForUnboundedWrites() {
     PCollection<Row> batchInput =

sdks/python/apache_beam/io/gcp/bigquery.py

@@ -2155,8 +2155,7 @@ def __init__(
         all of FILE_LOADS, STREAMING_INSERTS, and STORAGE_WRITE_API. Only
         applicable to unbounded input.
       num_storage_api_streams: Specifies the number of write streams that the
-        Storage API sink will use. This parameter is only applicable when
-        writing unbounded data.
+        Storage API sink will use.
       ignore_unknown_columns: Accept rows that contain values that do not match
         the schema. The unknown values are ignored. Default is False,
         which treats unknown values as errors. This option is only valid for

website/www/site/content/en/documentation/io/built-in/google-bigquery.md

@@ -835,8 +835,8 @@ TableSchema schema = new TableSchema().setFields(
 {{< code_sample "sdks/python/apache_beam/examples/snippets/snippets.py" model_bigqueryio_write_schema >}}
 {{< /highlight >}}
 
-For streaming pipelines, you need to set two additional parameters: the number
-of streams and the triggering frequency.
+For streaming pipelines, you need to set the triggering frequency. You can also
+set the number of streams for both batch and streaming pipelines.
 
 {{< highlight java >}}
 BigQueryIO.writeTableRows()
@@ -855,7 +855,8 @@ pipeline uses. You can set it explicitly on the transform via
 [`withNumStorageWriteApiStreams`](https://beam.apache.org/releases/javadoc/current/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.Write.html#withNumStorageWriteApiStreams-int-)
 or provide the `numStorageWriteApiStreams` option to the pipeline as defined in
 [`BigQueryOptions`](https://beam.apache.org/releases/javadoc/current/org/apache/beam/sdk/io/gcp/bigquery/BigQueryOptions.html).
-Please note this is only supported for streaming pipelines.
+For batch pipelines, a non-zero stream count inserts a redistribute; set it to
+0 or leave it unspecified to keep the pipeline parallelism as is.
 
 Triggering frequency determines how soon the data is visible for querying in
 BigQuery. You can explicitly set it via
@@ -874,10 +875,10 @@ pipelines.
 
 {{< paragraph class="language-java" wrap="span">}}
 Similar to streaming inserts, `STORAGE_WRITE_API` supports dynamically determining
-the number of parallel streams to write to BigQuery (starting 2.42.0). You can
-explicitly enable this using [`withAutoSharding`](https://beam.apache.org/releases/javadoc/current/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.Write.html#withAutoSharding--).
+the number of parallel streams to write to BigQuery for streaming pipelines
+(starting 2.42.0). You can explicitly enable this using [`withAutoSharding`](https://beam.apache.org/releases/javadoc/current/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.Write.html#withAutoSharding--).
 
-`STORAGE_WRITE_API` defaults to dynamic sharding when
+For streaming writes, `STORAGE_WRITE_API` defaults to dynamic sharding when
 `numStorageWriteApiStreams` is set to 0 or is unspecified.
 
 {{< /paragraph >}}