I am a software engineer at Apple focusing on building large scale data pipelines and the supporting infrastructure/development tools under the context of maps. I work closely with Spark communities inside Apple to make sure we deliver the most cutting-edge features to our developers.
May 27, 2021 11:35 AM PT
Zstandard is a fast compression algorithm which you can use in Apache Spark in various way. In this talk, I briefly summarized the evolution history of Apache Spark in this area and four main use cases and the benefits and the next steps:
1) ZStandard can optimize Spark local disk IO by compressing shuffle files significantly. This is very useful in K8s environments. It's beneficial not only when you use `emptyDir` with `memory` medium, but also it maximizes OS cache benefit when you use shared SSDs or container local storage. In Spark 3.2, SPARK-34390 takes advantage of ZStandard buffer pool feature and its performance gain is impressive, too.
2) Event log compression is another area to save your storage cost on the cloud storage like S3 and to improve the usability. SPARK-34503 officially switched the default event log compression codec from LZ4 to Zstandard.
3) Zstandard data file compression can give you more benefits when you use ORC/Parquet files as your input and output. Apache ORC 1.6 supports Zstandardalready and Apache Spark enables it via SPARK-33978. The upcoming Parquet 1.12 will support Zstandard compression.
4) Last, but not least, since Apache Spark 3.0, Zstandard is used to serialize/deserialize MapStatus data instead of Gzip.
There are more community works to utilize Zstandard to improve Spark. For example, Apache Avro community also supports Zstandard and SPARK-34479 aims to support Zstandard in Spark's avro file format in Spark 3.2.0.