Neo4j BigQuery Connector

This project is a prototype of a Dataproc template to power a BigQuery stored procedure for Apache Spark (aka Dataproc Serverless).

It allows for bidirectional data loading between Neo4j and BigQuery.

Building

The code is packaged into a Docker image that gets deployed by Dataproc onto the Spark environment.

To build:

$ docker build -t "europe-west2-docker.pkg.dev/your-gcp-project/connectors/neo4j-bigquery-connector:0.6.1"

Then push to Google Artifact Registry:

$ docker push "europe-west2-docker.pkg.dev/your-gcp-project/connectors/neo4j-bigquery-connector:0.6.1"

Note: you will need to enable your local gcloud tooling to help authenticate. Try running: gcloud auth configure-docker

Running

The template has been tested with AuraDS as well as self-managed GDS with Neo4j v5 Enterprise.

Network Prerequisites

In either case, you most likely need to configure a GCP network to use Private Google Access and possibly Cloud NAT. (Cloud NAT is definitely needed for AuraDS.)

Running Locally

This project uses poetry as the build tool. Install poetry, define your environment with poetry env use and invoke poetry install to install dependencies.

To build;

poetry build

Note: You may also need to install a Java 11/17 JRE and make sure JAVA_HOME is set.

Then invoke one of the main*.py entrypoint scripts using the command line arguments supported by the template. For example:

For BigQuery to GDS/AuraDS data movement;

$ poetry run python src/main.py --graph_name=mag240 --neo4j_db=neo4j \
    --neo4j_action="create_graph" \
    --neo4j_secret="projects/1055617507124/secrets/neo4j-bigquery-demo-2/versions/2" \
    --graph_uri="gcs://my-storage/graph-model.json" \
    --bq_project=neo4j-se-team-201905 --bq_dataset=bqr_neo4j_demo \
    --node_tables=AUTHOR,PAPER --edge_tables=PUBLISHED

For GDS/AuraDB to BigQuery data movement;

$ poetry run python src/main_to_bq.py --graph_name=mag240 --neo4j_db=neo4j \
    --neo4j_secret="projects/1055617507124/secrets/neo4j-bigquery-demo-2/versions/2" \
    --bq_project=neo4j-se-team-201905 --bq_dataset=bqr_neo4j_demo --bq_node_table=results_nodes \
    --bq_edge_table=results_edges \
    --neo4j_patterns="(:Paper{flag,years}),[:PUBLISHED{year}],(:Author{id})"

Submitting a Dataproc Serverless Job

If you're looking to just use the Dataproc capabilities or looking to do some quick testing, you can submit a batch job directly to Dataproc.

Using the gcloud tooling, use a shell script like:

#!/bin/sh
# Use fewer, larger executors
SPARK_EXE_CORES=8
SPARK_EXE_MEMORY=16g
SPARK_EXE_COUNT=2
PROPERTIES="spark.executor.cores=${SPARK_EXE_CORES}"
PROPERTIES="${PROPERTIES},spark.executor.memory=${SPARK_EXE_MEMORY}"
PROPERTIES="${PROPERTIES},spark.dynamicAllocation.initialExecutors=${SPARK_EXE_COUNT}"
PROPERTIES="${PROPERTIES},spark.dynamicAllocation.minExecutors=${SPARK_EXE_COUNT}"

gcloud dataproc batches submit pyspark \
    --region="europe-west1" \
    --version="2.1" \
    --deps-bucket="gs://your-bucket" \
    --container-image="europe-west2-docker.pkg.dev/your-gcp-project/connectors/neo4j-bigquery-connector:0.6.1" \
    --properties="${PROPERTIES}" \
    main.py -- \
    --graph_name=mag240 \
    --graph_uri="gs://your-bucket/folder/model.json" \
    --neo4j_database=neo4j \
    --neo4j_secret="projects/123456/secrets/neo4j-bigquery/versions/1" \
    --neo4j_action="create_graph" \
    --bq_project="your-gcp-project" \
    --bq_dataset="your_bq_dataset" \
    --node_tables="papers,authors,institution" \
    --edge_tables="citations,authorship,affiliation"

The key parts to note:

1. The arguments before main.py are specific to the PySpark job.
2. The arguments after the main.py -- are specific to the Dataproc template.

Customize (1) for your GCP environment and (2) for your AuraDS and BigQuery environments as needed.

Note: you can put configuration values in a JSON document stored in a Google Secret Manager secret (that's a mouthful). Use the --neo4j_secret parameter to pass in the full resource id (which should include the secret version number).

Configuring a Google BigQuery Stored Procedure

In short, you'll want to familiarize yourself with the Stored procedures for Apache Spark documentation. Assuming you've got your environment properly configured and enrolled in the preview program to use Spark for stored procedures, you need to create your stored procedure.

Creating the BigQuery --> Neo4j Procedure:

CREATE OR REPLACE PROCEDURE
  `my-gcp-project.your_bigquery_dataset.neo4j_gds_graph_project`(graph_name STRING,
    graph_uri STRING,
    neo4j_secret STRING,
    bq_project STRING,
    bq_dataset STRING,
    node_tables ARRAY<STRING>,
    edge_tables ARRAY<STRING>)
WITH CONNECTION `your-gcp-project.eu.spark-connection` OPTIONS (engine='SPARK',
    runtime_version='2.1',
    container_image='europe-west2-docker.pkg.dev/your-gcp-project/connectors/neo4j-bigquery-connector:0.6.1',
    properties=[],
    description="Project a graph from BigQuery into Neo4j AuraDS or GDS.")
  LANGUAGE python AS R"""
from pyspark.sql import SparkSession
from templates import BigQueryToNeo4jGDSTemplate

spark = (
      SparkSession
      .builder
      .appName("Neo4j BigQuery Connector")
      .getOrCreate()
)

template = BigQueryToNeo4jGDSTemplate()
args = template.parse_args(["--neo4j_action=create_graph"])
template.run(spark, args)
""";

Some details on the inputs:

• graph_name -- the resulting name of the graph projection in AuraDS
• graph_uri -- the GCS uri pointing to a JSON file describing the graph model for your data
• neo4j_secret -- a Google Secret Manager secret resource id containing a JSON blob with additional arguments:
  • neo4j_user -- name of the Neo4j user to connect as
  • neo4j_password -- password for the given user
  • neo4j_uri -- Connection URI of the AuraDS instance
• bq_project -- GCP project id owning the BigQuery source data
• bq_dataset -- BigQuery dataset name for the source data
• node_tables -- an ARRAY<STRING> of BigQuery table names representing nodes
• edge_tables -- an ARRAY<STRING> of BigQuery table names representing edges

Note: you can leverage the fact the secret payload is JSON to tuck in any additional, supported arguments not exposed by your stored procedure. (For instance, you could override the default neo4j_concurrency setting.)

An example BigQuery SQL statement that calls the procedure:

DECLARE graph_name STRING DEFAULT "test-graph";
DECLARE graph_uri STRING DEFAULT "gs://your-bucket/folder/model.json";
DECLARE neo4j_secret STRING DEFAULT "projects/123456/secrets/neo4j-bigquery/versions/1";
DECLARE bq_project STRING DEFAULT "your-gcp-project";
DECLARE bq_dataset STRING DEFAULT "your_bq_dataset";
DECLARE node_tables ARRAY<STRING> DEFAULT ["papers", "authors", "institution"];
DECLARE edge_tables ARRAY<STRING> DEFAULT ["citations", "authorship", "affiliation"];

CALL `your-gcp-project.your_bq_dataset.neo4j_gds_graph_project`(
    graph_name, graph_uri, neo4j_secret, bq_project, bq_dataset,
    node_tables, edge_tables);

Creating the Neo4j --> BigQuery Procedures

One Dataproc template (Neo4jGDSToBigQueryTemplate) supports writing Nodes or Relationships back to BigQuery from AuraDS/GDS. The mode is simply toggled via a --bq_sink_mode parameter that can either be hardcoded (like below) to make distinct stored procedures or exposed as a parameter for the user to populate.

For Nodes:

CREATE
OR REPLACE PROCEDURE
  `your-gcp-project.your_bigquery_dataset.neo4j_gds_stream_graph`(graph_name STRING,
    neo4j_secret STRING,
    bq_project STRING,
    bq_dataset STRING,
    bq_node_table STRING,
    bq_edge_table STRING,
    neo4j_patterns ARRAY<STRING>)
WITH CONNECTION `team-connectors-dev.eu.spark-connection` OPTIONS (engine='SPARK',
    runtime_version='2.1',
    container_image='europe-west2-docker.pkg.dev/your-gcp-project/connectors/neo4j-bigquery-connector:0.6.1',
    properties=[("spark.driver.cores", "8"),
        ("spark.driver.maxResultSize", "4g"),
        ("spark.driver.memory", "16g")],
    description="Stream graph entities from Neo4j AuraDS/GDS to BigQuery")
  LANGUAGE python AS R"""
from pyspark.sql import SparkSession
from templates import Neo4jGDSToBigQueryTemplate

spark = (
	SparkSession
	.builder
	.appName("Neo4j -> BigQuery Connector")
	.getOrCreate()
)

template = Neo4jGDSToBigQueryTemplate()
args = template.parse_args()
template.run(spark, args)
""";

Some details on the inputs:

• graph_name -- the name of the graph in AuraDS you're reading
• neo4j_secret -- a Google Secret Manager secret resource id containing a JSON blob with additional arguments:
  • neo4j_user -- name of the Neo4j user to connect as
  • neo4j_password -- password for the given user
  • neo4j_uri -- Connection URI of the AuraDS instance
• bq_project -- GCP project id owning the BigQuery source data
• bq_dataset -- BigQuery dataset name for the source data
• bq_node_table -- BigQuery table name to write nodes into
• bq_edge_table -- BigQuery table name to write edges into
• neo4j_patterns -- an ARRAY<STRING> of neo4j patterns to query from GDS/AuraDS, in the form of Cypher style node or relationship patterns. e.g. (:Author{id,birth_year}) for nodes, [:KNOWS{since_year}] for relationships.

Note: Writing back to BigQuery is currently subject to pre-planning your Spark environment to accommodate data sizes.

See Dataproc Serverless docs

for options for increasing CPU or memory for Spark workers/executors.

Current Caveats

• All known caveats for populating GDS via Arrow Flight apply (e.g. node id formats, etc.).
• Concurrency doesn't auto-tune. Current recommendation is to set neo4j_concurrency to the number of AuraDS CPU / 2 at minimum, but it's not clear how much it helps.

Copyright and Licensing

All artifacts and code in this project, unless noted in their respective files, are copyright Neo4j and made available under the Apache License, Version 2.0.

No support is currently provided.