Extending Spark SQL 2.4 with New Data Sources (Live Coding Session)
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The document outlines a live coding session focused on extending Spark SQL 2.4 with new data sources, emphasizing the importance of developing new data sources to enhance data accessibility for external systems. It details the goals, frameworks, and APIs involved in loading and saving data, and it introduces the DataFrameReader as a key component for data flow description. Additionally, it touches on the evolution from Data Source API v1 to v2, offering insights for developers and data engineers on the capabilities of Spark SQL.
Extending Spark SQL 2.4 with New Data Sources (Live Coding Session)
- 1. Extending Spark SQL 2.4 with New Data Sources Live Coding Session © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl / Spark+AI Summit 2019
- 2. ● Freelance IT consultant ● Specializing in Spark, Kafka, Kafka Streams, Scala ● Development | Consulting | Training | Speaking ● "The Internals Of" online books ● Among contributors to Apache Spark ● Among Confluent Community Catalyst (Class of 2019 - 2020) ● Contact me at jacek@japila.pl ● Follow @JacekLaskowski on twitter for more #ApacheSpark #ApacheKafka #KafkaStreams Jacek Laskowski
- 3. Friendly reminder Pictures...take a lot of pictures! 📷 © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl
- 4. Why Should You Care? 1. Why would you ever consider developing a new data source for Spark SQL? 2. Let structured queries access data in external systems (e.g. Splice Machine, Google Cloud Spanner) 3. Make loading or writing process self-contained a. Hidden from developers who'd focus on what to do with the data not how to make the data available in a proper format © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl
- 5. Data Source / Data Provider 1. Data Source is an pluggable “abstraction” in Spark SQL for loading and saving data a. Abstraction in a loose meaning b. Also known as Data Provider or Data Format or Relation Provider 2. Built-In Data Sources: parquet, kafka, avro, json, etc. 3. All available for developers, data engineers, and data scientists a. Scala, Java, Python, SQL 4. Allows for new data sources 5. Source or Reader for loading data 6. Sink or Writer for saving data 7. Read up on Data Sources in the official documentation © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl The goal of the session! 🎯
- 6. Before Developing New Data Source 1. What Apache Spark version? 2. Data Source API V1 vs Data Source API V2? 3. Loading and/or Saving Data? 4. Spark SQL only? 5. Spark Structured Streaming? a. Micro-Batch Stream Processing? b. Continuous Stream Processing? © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl
- 7. DataFrameReader (1 of 2) © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl 1. SparkSession.read to start describing a data flow a. Creates a DataFrameReader 2. DataFrameReader is a fluent interface to describe the input data source 3. Used to “load” data from external storage systems (e.g. file systems, key-value stores, etc.) a. No physical data movement yet b. Metadata of an input node in a data flow (graph) 4. DataFrameReader.load to finish describing the input
- 8. DataFrameReader (2 of 2) © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl Worth noticing: 1. DataSource.lookupDataS ource 2. DataSourceV2 3. ReadSupport 4. DataSourceV2Relation 5. loadV1Source
- 10. loadV1Source = DataSource.resolveRelation 1. loadV1Source loads a DataSource API V1 data source © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl
- 11. Data Source API © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl 1. DataSourceRegister 2. 👉 Data Source API V1 3. 👉 Data Source API V2
- 12. Friendly reminders 1. Pictures...take a lot of pictures! 📷 2. It should be a live coding, shouldn’t it? 🤔 © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl
- 13. Data Source API V1 © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl 1. DataSourceRegister a. SchemaRelationProvider b. RelationProvider c. FileFormat d. CreatableRelationProvider 2. BaseRelation a. PrunedFilteredScan b. InsertableRelation c. PrunedScan d. TableScan e. CatalystScan
- 14. Data Source API V2 © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl 1. DataSourceRegister 2. DataSourceV2 3. ReadSupport 4. WriteSupport
- 15. “The Internals Of” Online Books 1. The Internals of Spark SQL 2. The Internals of Spark Structured Streaming 3. The Internals of Apache Spark
- 16. Questions? 1. Follow @jaceklaskowski on twitter (DMs open) 2. Upvote my questions and answers on StackOverflow 3. Contact me at jacek@japila.pl 4. Connect with me at LinkedIn © Jacek Laskowski / @JacekLaskowski / jacek@japila.pl