[
https://issues.apache.org/jira/browse/BEAM-1857?focusedWorklogId=678984&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-678984
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ASF GitHub Bot logged work on BEAM-1857:
----------------------------------------
Author: ASF GitHub Bot
Created on: 09/Nov/21 11:33
Start Date: 09/Nov/21 11:33
Worklog Time Spent: 10m
Work Description: mosche commented on a change in pull request #15916:
URL: https://github.com/apache/beam/pull/15916#discussion_r745529126
##########
File path:
sdks/java/io/neo4j/src/main/java/org/apache/beam/sdk/io/neo4j/Neo4jIO.java
##########
@@ -0,0 +1,1358 @@
+/*
+ * 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.neo4j;
+
+import static
org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+
+import com.google.auto.value.AutoValue;
+import java.io.Serializable;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import org.apache.beam.repackaged.core.org.apache.commons.lang3.StringUtils;
+import org.apache.beam.sdk.annotations.Experimental;
+import org.apache.beam.sdk.coders.Coder;
+import org.apache.beam.sdk.harness.JvmInitializer;
+import org.apache.beam.sdk.options.ValueProvider;
+import org.apache.beam.sdk.schemas.NoSuchSchemaException;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.SchemaRegistry;
+import org.apache.beam.sdk.transforms.DoFn;
+import org.apache.beam.sdk.transforms.PTransform;
+import org.apache.beam.sdk.transforms.ParDo;
+import org.apache.beam.sdk.transforms.SerializableFunction;
+import org.apache.beam.sdk.transforms.display.DisplayData;
+import org.apache.beam.sdk.transforms.display.HasDisplayData;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.beam.sdk.values.PDone;
+import org.apache.beam.sdk.values.TypeDescriptor;
+import
org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.neo4j.driver.AuthTokens;
+import org.neo4j.driver.Config;
+import org.neo4j.driver.Driver;
+import org.neo4j.driver.GraphDatabase;
+import org.neo4j.driver.Logging;
+import org.neo4j.driver.Record;
+import org.neo4j.driver.Result;
+import org.neo4j.driver.Session;
+import org.neo4j.driver.SessionConfig;
+import org.neo4j.driver.TransactionConfig;
+import org.neo4j.driver.TransactionWork;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This is a Beam IO to read from, and write data to, Neo4j.
+ *
+ * <p>
+ *
+ * <p>
+ *
+ * <h3>Driver configuration</h3>
+ *
+ * <p>To read from or write to Neo4j you have to provide a {@link
DriverConfiguration} using<br>
+ * 1. {@link DriverConfiguration#create()} (which must be {@link
Serializable});<br>
+ * 2. or {@link DriverConfiguration#create(String, String, String)} (URL,
username and password).
+ *
+ * <p>If you have trouble connecting to a Neo4j Aura database please try to
disable a few security
+ * algorithms in your JVM. This makes sure that the right one is picked to
connect:
+ *
+ * <p>
+ *
+ * <pre>{@code
+ * Security.setProperty(
+ * "jdk.tls.disabledAlgorithms",
+ * "SSLv3, RC4, DES, MD5withRSA, DH keySize < 1024, EC keySize < 224,
3DES_EDE_CBC, anon, NULL");
+ * }</pre>
+ *
+ * <p>
+ *
+ * <p>
+ *
+ * <p>To execute this code on GCP Dataflow you can create a class which
extends {@link
+ * JvmInitializer} and implement the {@link JvmInitializer#onStartup()}
method. You need to annotate
+ * this new class with {@link com.google.auto.service.AutoService}
+ *
+ * <pre>{@code
+ * @AutoService(value = JvmInitializer.class)
+ * }</pre>
+ *
+ * <p>
+ *
+ * <h3>Reading from Neo4j</h3>
+ *
+ * <p>{@link Neo4jIO#read()} source returns a bounded collection of {@code
OuptutT} as a {@code
+ * PCollection<OutputT>}. OutputT is the type returned by the provided {@link
RowMapper}. It accepts
+ * parameters as input in the form of {@code ParameterT} as a {@code
PCollection<ParameterT>}
+ *
+ * <p>The following example reads ages to return the IDs of Person nodes. It
runs a Cypher query for
+ * each provided age.
+ *
+ * <p>The {@link ParametersMapper} maps input values to each execution of the
Cypher statement.
+ * These parameter values are stored in a {@link Map} (mapping String to
Object). The map is cleared
+ * after each execution.
+ *
+ * <p>The {@link RowMapper} converts output Neo4j {@link Record} values to the
output of the source.
+ *
+ * <pre>{@code
+ * pipeline.apply( Neo4jIO.<Integer, String>read()
+ *
.withDriverConfiguration(Neo4jIO.DriverConfiguration.create("neo4j://localhost:7687",
"neo4j", "password"))
+ * .withCypher("MATCH(n:Person) WHERE n.age = $age RETURN n.id")
+ * .withReadTransaction()
+ * .withCoder(StringUtf8Coder.of())
+ * .withParametersMapper((age, rowMap) -> rowMap.put("age", age))
+ * .withRowMapper( record -> return record.get(0).asString() )
+ * );
+ * }</pre>
+ *
+ * <h3>Writing to Neo4j</h3>
+ *
+ * <p>Neo4j sink supports writing data to a graph. It writes a {@link
PCollection} to the graph by
+ * collecting a batch of rows after which all rows in this batch are written
together to Neo4j. This
+ * is done using the {@link WriteUnwind} sink transform.
+ *
+ * <p>Like the source, to configure the sink, you have to provide a {@link
DriverConfiguration}.
+ *
+ * <p>In the following example we'll merge a collection of {@link
org.apache.beam.sdk.values.Row}
+ * into Person nodes. Since this is a Sink it has no output and as such no
RowMapper is needed. The
+ * rows are being used as a container for the parameters of the Cypher
statement. The used Cypher in
+ * question needs to be an UNWIND statement. Like in the read case, the {@link
ParametersMapper}
+ * maps values to a {@link Map<String, Object>}. The difference is that the
resulting Map is stored
+ * in a {@link List} (containing maps) which in turn is stored in another Map
under the name
+ * provided by the {@link WriteUnwind#withUnwindMapName(String)} method. All
of this is handled
+ * automatically. You do need to provide the unwind map name so that you can
reference that in the
+ * UNWIND statement.
+ *
+ * <p>
+ *
+ * <p>For example:
+ *
+ * <pre>{@code
+ * pipeline
+ * .apply(...)
+ * .apply(Neo4jIO.<Row>writeUnwind()
+ *
.withDriverConfiguration(Neo4jIO.DriverConfiguration.create("neo4j://localhost:7687",
"neo4j", "password"))
+ * .withUnwindMapName("rows")
+ * .withCypher("UNWIND $rows AS row MERGE(n:Person { id : row.id } ) SET
n.firstName = row.first, n.lastName = row.last")
+ * .withParametersMapper( (row, map ) -> {
+ * map.put("id", row.getString("id));
+ * map.put("first", row.getString("firstName"));
+ * map.put("last", row.getString("lastName"));
+ * })
+ * );
+ * }</pre>
+ */
+@Experimental(Experimental.Kind.SOURCE_SINK)
+public class Neo4jIO {
+
+ private static final Logger LOG = LoggerFactory.getLogger(Neo4jIO.class);
+
+ /**
+ * Read all rows using a Neo4j Cypher query.
+ *
+ * @param <ParameterT> Type of the data representing query parameters.
+ * @param <OutputT> Type of the data to be read.
+ */
+ public static <ParameterT, OutputT> Read<ParameterT, OutputT> read() {
+ return new AutoValue_Neo4jIO_Read.Builder<ParameterT, OutputT>()
+
.setFetchSize(ValueProvider.StaticValueProvider.of(Config.defaultConfig().fetchSize()))
+ .build();
+ }
+
+ /**
+ * Write all rows using a Neo4j Cypher UNWIND cypher statement. This sets a
default batch batch
+ * size of 5000.
+ *
+ * @param <ParameterT> Type of the data representing query parameters.
+ */
+ public static <ParameterT> WriteUnwind<ParameterT> writeUnwind() {
+ return new AutoValue_Neo4jIO_WriteUnwind.Builder<ParameterT>()
+ .setBatchSize(ValueProvider.StaticValueProvider.of(5000L))
+ .build();
+ }
+
+ private static <ParameterT, OutputT> PCollection<OutputT>
getOutputPCollection(
+ PCollection<ParameterT> input, DoFn<ParameterT, OutputT> writeFn,
Coder<OutputT> coder) {
+ PCollection<OutputT> output =
input.apply(ParDo.of(writeFn)).setCoder(coder);
+
+ try {
+ TypeDescriptor<OutputT> typeDesc = coder.getEncodedTypeDescriptor();
+ SchemaRegistry registry = input.getPipeline().getSchemaRegistry();
+ Schema schema = registry.getSchema(typeDesc);
+ output.setSchema(
+ schema,
+ typeDesc,
+ registry.getToRowFunction(typeDesc),
+ registry.getFromRowFunction(typeDesc));
+ } catch (NoSuchSchemaException e) {
+ // ignore
+ }
+ return output;
+ }
+
+ /**
+ * An interface used by {@link Read} for converting each row of a Neo4j
{@link Result} record
+ * {@link Record} into an element of the resulting {@link PCollection}.
+ */
+ @FunctionalInterface
+ public interface RowMapper<T> extends Serializable {
+ T mapRow(Record record) throws Exception;
+ }
+
+ /**
+ * An interface used by {@link Read} for converting input parameter data to
a parameters map which
+ * can be used by your Neo4j cypher query.
+ */
+ @FunctionalInterface
+ public interface ParametersMapper<ParameterT> extends Serializable {
+ /**
+ * Simply map an input record to a parameters map.
+ *
+ * @param input the input read
+ * @param parametersMap the parameters map to update in this llabmda
+ */
+ void mapParameters(ParameterT input, Map<String, Object> parametersMap);
Review comment:
Looking at the code I was wondering if this mapper needs to be stateful?
Can't this just be a function `ParameterT -> Map<String, Object>`?
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Issue Time Tracking
-------------------
Worklog Id: (was: 678984)
Time Spent: 1h 50m (was: 1h 40m)
> Add Neo4jIO
> -----------
>
> Key: BEAM-1857
> URL: https://issues.apache.org/jira/browse/BEAM-1857
> Project: Beam
> Issue Type: New Feature
> Components: io-ideas
> Reporter: kassem shehady
> Priority: P2
> Labels: stale-P2
> Time Spent: 1h 50m
> Remaining Estimate: 0h
>
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