You are viewing a plain text version of this content. The canonical link for it is here.
Posted to github@beam.apache.org by GitBox <gi...@apache.org> on 2020/07/02 00:48:15 UTC
[GitHub] [beam] TheNeuralBit commented on a change in pull request #12090: [BEAM-10336,BEAM-10337] Add SchemaIO abstraction and implement for PubSub
TheNeuralBit commented on a change in pull request #12090:
URL: https://github.com/apache/beam/pull/12090#discussion_r448684950
##########
File path: sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/pubsub/PubsubSchemaCapableIOProvider.java
##########
@@ -0,0 +1,286 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.sdk.io.gcp.pubsub;
+
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.ATTRIBUTES_FIELD;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.DLQ_TAG;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.MAIN_TAG;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.PAYLOAD_FIELD;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.TIMESTAMP_FIELD;
+import static org.apache.beam.sdk.schemas.Schema.TypeName.ROW;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+
+import com.google.auto.service.AutoService;
+import java.io.Serializable;
+import java.nio.charset.StandardCharsets;
+import org.apache.beam.sdk.annotations.Internal;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.Schema.FieldType;
+import org.apache.beam.sdk.schemas.io.InvalidConfigurationException;
+import org.apache.beam.sdk.schemas.io.InvalidSchemaException;
+import org.apache.beam.sdk.schemas.io.SchemaCapableIOProvider;
+import org.apache.beam.sdk.schemas.io.SchemaIO;
+import org.apache.beam.sdk.schemas.transforms.DropFields;
+import org.apache.beam.sdk.transforms.MapElements;
+import org.apache.beam.sdk.transforms.PTransform;
+import org.apache.beam.sdk.transforms.ToJson;
+import org.apache.beam.sdk.transforms.WithTimestamps;
+import org.apache.beam.sdk.values.PBegin;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.PCollectionTuple;
+import org.apache.beam.sdk.values.POutput;
+import org.apache.beam.sdk.values.Row;
+import org.apache.beam.sdk.values.TypeDescriptor;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableMap;
+
+/**
+ * {@link SchemaCapableIOProvider} to create {@link PubsubSchemaIO} that implements {@link
+ * SchemaIO}.
+ *
+ * <p>If useFlatSchema of {@link PubsubSchemaIO} is not set, schema must contain exactly fields
+ * 'event_timestamp', 'attributes, and 'payload'. Else, it must contain just 'event_timestamp'. See
+ * {@link PubsubMessageToRow} for details.
Review comment:
`PubsubSchemaIO.useFlatSchema` is an implementation detail, this should instead be phrased like "The data schema passed to `from` must take one of two forms: the "nested" style or the "flat" style ... "
The javadoc for `PubsubIOJsonTable` has some good language about this that you could draw from.
##########
File path: sdks/java/extensions/sql/src/test/java/org/apache/beam/sdk/io/gcp/pubsub/PubsubMessageToRowTest.java
##########
@@ -48,7 +47,7 @@
import org.junit.Rule;
import org.junit.Test;
-/** Unit tests for {@link PubsubMessageToRow}. */
+/** Unit tests for {@link org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow}. */
Review comment:
```suggestion
/** Unit tests for {@link PubsubMessageToRow}. */
```
nit: IntelliJ probably did this automatically when PubsubMessageToRow was temporarily in a different package. Just the class name should be fine.
##########
File path: sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/pubsub/PubsubSchemaCapableIOProvider.java
##########
@@ -0,0 +1,286 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.sdk.io.gcp.pubsub;
+
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.ATTRIBUTES_FIELD;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.DLQ_TAG;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.MAIN_TAG;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.PAYLOAD_FIELD;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.TIMESTAMP_FIELD;
+import static org.apache.beam.sdk.schemas.Schema.TypeName.ROW;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+
+import com.google.auto.service.AutoService;
+import java.io.Serializable;
+import java.nio.charset.StandardCharsets;
+import org.apache.beam.sdk.annotations.Internal;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.Schema.FieldType;
+import org.apache.beam.sdk.schemas.io.InvalidConfigurationException;
+import org.apache.beam.sdk.schemas.io.InvalidSchemaException;
+import org.apache.beam.sdk.schemas.io.SchemaCapableIOProvider;
+import org.apache.beam.sdk.schemas.io.SchemaIO;
+import org.apache.beam.sdk.schemas.transforms.DropFields;
+import org.apache.beam.sdk.transforms.MapElements;
+import org.apache.beam.sdk.transforms.PTransform;
+import org.apache.beam.sdk.transforms.ToJson;
+import org.apache.beam.sdk.transforms.WithTimestamps;
+import org.apache.beam.sdk.values.PBegin;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.PCollectionTuple;
+import org.apache.beam.sdk.values.POutput;
+import org.apache.beam.sdk.values.Row;
+import org.apache.beam.sdk.values.TypeDescriptor;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableMap;
+
+/**
+ * {@link SchemaCapableIOProvider} to create {@link PubsubSchemaIO} that implements {@link
+ * SchemaIO}.
Review comment:
```suggestion
* An implementation of {@link SchemaCapableIOProvider} for reading and writing JSON payloads
* with {@link PubsubIO}.
```
##########
File path: sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/meta/provider/pubsub/PubsubIOJsonTable.java
##########
@@ -122,14 +115,14 @@
@Experimental
class PubsubIOJsonTable extends BaseBeamTable implements Serializable {
Review comment:
This class doesn't actually have anything specific to pubsub in it anymore, it's just a generic wrapper that could be used for any `SchemaIO`. Could you rename it to something like `SchemaIOTable` and remove references to pubsub?
The javadoc for this class should also be removed and incorporate into the one for `PubsubSchemaCapableIOProvider` (but without the specific examples using SQL syntax).
##########
File path: sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/pubsub/PubsubSchemaCapableIOProvider.java
##########
@@ -0,0 +1,264 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.sdk.io.gcp.pubsub;
+
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.ATTRIBUTES_FIELD;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.DLQ_TAG;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.MAIN_TAG;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.PAYLOAD_FIELD;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.TIMESTAMP_FIELD;
+import static org.apache.beam.sdk.schemas.Schema.TypeName.ROW;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+
+import com.google.auto.service.AutoService;
+import java.io.Serializable;
+import java.nio.charset.StandardCharsets;
+import org.apache.beam.sdk.annotations.Internal;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.Schema.FieldType;
+import org.apache.beam.sdk.schemas.io.InvalidConfigurationException;
+import org.apache.beam.sdk.schemas.io.SchemaCapableIOProvider;
+import org.apache.beam.sdk.schemas.io.SchemaIO;
+import org.apache.beam.sdk.schemas.transforms.DropFields;
+import org.apache.beam.sdk.transforms.MapElements;
+import org.apache.beam.sdk.transforms.PTransform;
+import org.apache.beam.sdk.transforms.ToJson;
+import org.apache.beam.sdk.transforms.WithTimestamps;
+import org.apache.beam.sdk.values.PBegin;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.PCollectionTuple;
+import org.apache.beam.sdk.values.POutput;
+import org.apache.beam.sdk.values.Row;
+import org.apache.beam.sdk.values.TypeDescriptor;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableMap;
+
+/**
+ * {@link org.apache.beam.sdk.schemas.io.SchemaCapableIOProvider} to create {@link PubsubSchemaIO}
+ * that implements {@link org.apache.beam.sdk.schemas.io.SchemaIO}.
+ */
+@Internal
+@AutoService(SchemaCapableIOProvider.class)
+public class PubsubSchemaCapableIOProvider implements SchemaCapableIOProvider {
+ public static final FieldType VARCHAR = FieldType.STRING;
+ public static final FieldType TIMESTAMP = FieldType.DATETIME;
+
+ /** Returns an id that uniquely represents this IO. */
+ @Override
+ public String identifier() {
+ return "pubsub";
+ }
+
+ /**
+ * Returns the expected schema of the configuration object. Note this is distinct from the schema
+ * of the data source itself.
+ */
+ @Override
+ public Schema configurationSchema() {
+ return Schema.builder()
+ .addNullableField("timestampAttributeKey", FieldType.STRING)
+ .addNullableField("deadLetterQueue", FieldType.STRING)
+ .build();
+ }
+
+ /**
+ * Produce a SchemaIO given a String representing the data's location, the schema of the data that
+ * resides there, and some IO-specific configuration object.
+ */
+ @Override
+ public PubsubSchemaIO from(String location, Row configuration, Schema dataSchema) {
+ validateDlq(configuration.getValue("deadLetterQueue"));
+ validateEventTimestamp(dataSchema);
+ return PubsubSchemaIO.withConfiguration(location, configuration, dataSchema);
+ }
+
+ private void validateEventTimestamp(Schema schema) {
+ if (!PubsubSchemaIO.fieldPresent(schema, TIMESTAMP_FIELD, TIMESTAMP)) {
+ throw new InvalidConfigurationException(
+ "Unsupported schema specified for Pubsub source in CREATE TABLE."
+ + "CREATE TABLE for Pubsub topic must include at least 'event_timestamp' field of "
+ + "type 'TIMESTAMP'");
+ }
+ }
+
+ private void validateDlq(String deadLetterQueue) {
+ if (deadLetterQueue != null && deadLetterQueue.isEmpty()) {
+ throw new InvalidConfigurationException("Dead letter queue topic name is not specified");
+ }
+ }
+
+ /** An abstraction to create schema aware IOs. */
+ @Internal
+ private static class PubsubSchemaIO implements SchemaIO, Serializable {
+ protected final Row config;
+ protected final Schema dataSchema;
+ protected final String location;
+ protected final Boolean useFlatSchema;
+
+ private PubsubSchemaIO(String location, Row config, Schema dataSchema) {
+ this.config = config;
+ this.dataSchema = dataSchema;
+ this.location = location;
+ this.useFlatSchema = !definesAttributeAndPayload(dataSchema);
+ }
+
+ static PubsubSchemaIO withConfiguration(String location, Row config, Schema dataSchema) {
+ return new PubsubSchemaIO(location, config, dataSchema);
+ }
+
+ @Override
+ public Schema schema() {
+ return dataSchema;
+ }
+
+ @Override
+ public PTransform<PBegin, PCollection<Row>> buildReader() {
+ return new PTransform<PBegin, PCollection<Row>>() {
+ @Override
+ public PCollection<Row> expand(PBegin begin) {
+ PCollectionTuple rowsWithDlq =
+ begin
+ .apply("ReadFromPubsub", readMessagesWithAttributes())
+ .apply(
+ "PubsubMessageToRow",
+ PubsubMessageToRow.builder()
+ .messageSchema(dataSchema)
+ .useDlq(useDlqCheck(config))
+ .useFlatSchema(useFlatSchema)
+ .build());
+ rowsWithDlq.get(MAIN_TAG).setRowSchema(dataSchema);
+
+ if (useDlqCheck(config)) {
+ rowsWithDlq.get(DLQ_TAG).apply(writeMessagesToDlq());
+ }
+
+ return rowsWithDlq.get(MAIN_TAG);
+ }
+ };
+ }
+
+ @Override
+ public PTransform<PCollection<Row>, POutput> buildWriter() {
+ if (!useFlatSchema) {
+ throw new UnsupportedOperationException(
+ "Writing to a Pubsub topic is only supported for flattened schemas");
+ }
+
+ return new PTransform<PCollection<Row>, POutput>() {
+ @Override
+ public POutput expand(PCollection<Row> input) {
+ return input
+ .apply(RowToPubsubMessage.fromTableConfig(config, useFlatSchema))
+ .apply(createPubsubMessageWrite());
+ }
+ };
+ }
+
+ private PubsubIO.Read<PubsubMessage> readMessagesWithAttributes() {
+ PubsubIO.Read<PubsubMessage> read = PubsubIO.readMessagesWithAttributes().fromTopic(location);
+
+ return useTimestampAttribute(config)
+ ? read.withTimestampAttribute(config.getValue("timestampAttributeKey"))
+ : read;
+ }
+
+ private PubsubIO.Write<PubsubMessage> createPubsubMessageWrite() {
+ PubsubIO.Write<PubsubMessage> write = PubsubIO.writeMessages().to(location);
+ if (useTimestampAttribute(config)) {
+ write = write.withTimestampAttribute(config.getValue("timestampAttributeKey"));
+ }
+ return write;
+ }
+
+ private PubsubIO.Write<PubsubMessage> writeMessagesToDlq() {
+ PubsubIO.Write<PubsubMessage> write =
+ PubsubIO.writeMessages().to(config.getString("deadLetterQueue"));
+
+ return useTimestampAttribute(config)
+ ? write.withTimestampAttribute(config.getString("timestampAttributeKey"))
+ : write;
+ }
+
+ private boolean useDlqCheck(Row config) {
+ return config.getValue("deadLetterQueue") != null;
+ }
+
+ private boolean useTimestampAttribute(Row config) {
+ return config.getValue("timestampAttributeKey") != null;
+ }
+
+ private boolean definesAttributeAndPayload(Schema schema) {
+ return fieldPresent(
+ schema, ATTRIBUTES_FIELD, Schema.FieldType.map(VARCHAR.withNullable(false), VARCHAR))
+ && (schema.hasField(PAYLOAD_FIELD)
+ && ROW.equals(schema.getField(PAYLOAD_FIELD).getType().getTypeName()));
+ }
+
+ private static boolean fieldPresent(
+ Schema schema, String field, Schema.FieldType expectedType) {
+ return schema.hasField(field)
+ && expectedType.equivalent(
+ schema.getField(field).getType(), Schema.EquivalenceNullablePolicy.IGNORE);
+ }
+ }
+
+ /**
+ * A {@link PTransform} to convert {@link Row} to {@link PubsubMessage} with JSON payload.
+ *
+ * <p>Currently only supports writing a flat schema into a JSON payload. This means that all Row
+ * field values are written to the {@link PubsubMessage} JSON payload, except for {@code
+ * event_timestamp}, which is either ignored or written to the message attributes, depending on
+ * whether config.getValue("timestampAttributeKey") is set.
+ */
+ private static class RowToPubsubMessage
Review comment:
Yeah I think it makes sense to keep this separate and package-private, it will minimize the diff as well since it's just a file rename.
Sorry for the churn Scott, could you move this back into it's own class?
##########
File path: sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/pubsub/PubsubSchemaCapableIOProvider.java
##########
@@ -0,0 +1,286 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.sdk.io.gcp.pubsub;
+
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.ATTRIBUTES_FIELD;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.DLQ_TAG;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.MAIN_TAG;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.PAYLOAD_FIELD;
+import static org.apache.beam.sdk.io.gcp.pubsub.PubsubMessageToRow.TIMESTAMP_FIELD;
+import static org.apache.beam.sdk.schemas.Schema.TypeName.ROW;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+
+import com.google.auto.service.AutoService;
+import java.io.Serializable;
+import java.nio.charset.StandardCharsets;
+import org.apache.beam.sdk.annotations.Internal;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.Schema.FieldType;
+import org.apache.beam.sdk.schemas.io.InvalidConfigurationException;
+import org.apache.beam.sdk.schemas.io.InvalidSchemaException;
+import org.apache.beam.sdk.schemas.io.SchemaCapableIOProvider;
+import org.apache.beam.sdk.schemas.io.SchemaIO;
+import org.apache.beam.sdk.schemas.transforms.DropFields;
+import org.apache.beam.sdk.transforms.MapElements;
+import org.apache.beam.sdk.transforms.PTransform;
+import org.apache.beam.sdk.transforms.ToJson;
+import org.apache.beam.sdk.transforms.WithTimestamps;
+import org.apache.beam.sdk.values.PBegin;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.PCollectionTuple;
+import org.apache.beam.sdk.values.POutput;
+import org.apache.beam.sdk.values.Row;
+import org.apache.beam.sdk.values.TypeDescriptor;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableMap;
+
+/**
+ * {@link SchemaCapableIOProvider} to create {@link PubsubSchemaIO} that implements {@link
+ * SchemaIO}.
+ *
+ * <p>If useFlatSchema of {@link PubsubSchemaIO} is not set, schema must contain exactly fields
+ * 'event_timestamp', 'attributes, and 'payload'. Else, it must contain just 'event_timestamp'. See
+ * {@link PubsubMessageToRow} for details.
+ *
+ * <p>{@link #configurationSchema()} consists of two attributes, timestampAttributeKey and
+ * deadLetterQueue.
+ *
+ * <p>timestampAttributeKey is an optional attribute key of the Pubsub message from which to extract
+ * the event timestamp.
+ *
+ * <p>This attribute has to conform to the same requirements as in {@link
+ * PubsubIO.Read.Builder#withTimestampAttribute}.
+ *
+ * <p>Short version: it has to be either millis since epoch or string in RFC 3339 format.
+ *
+ * <p>If the attribute is specified then event timestamps will be extracted from the specified
+ * attribute. If it is not specified then message publish timestamp will be used.
+ *
+ * <p>deadLetterQueue is an optional topic path which will be used as a dead letter queue.
+ *
+ * <p>Messages that cannot be processed will be sent to this topic. If it is not specified then
+ * exception will be thrown for errors during processing causing the pipeline to crash.
Review comment:
This feels a bit fractured now, It might help to give it a little structure with some headers and/or bulleted lists like we do in [BigQueryIO](https://github.com/apache/beam/blob/master/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.java) ([rendered](https://beam.apache.org/releases/javadoc/2.22.0/org/apache/beam/sdk/io/gcp/bigquery/BigQueryIO.html)).
Maybe something like:
```html
<h2>Schema</h2>
...
<h2>Configuration</h2>
...
<h3>timestampAttributeKey</h3>
...
<h3>deadLetterQueueue</h3>
...
```
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org