Learnings from the Field: How to Give Your Spark Streaming Jobs a 15x Speed Boost Using the Lesser-Known Parameter

Canadian Data Guy
4 min readMar 3, 2024

Introduction:

In the realm of big data processing, where efficiency and speed are paramount, Apache Spark shines as a potent tool. Yet, the true power of Spark often lies in the nuances of its configuration, particularly in a parameter that might not catch the eye at first glance: spark.sql.files.maxPartitionBytes. This blog unveils how a subtle tweak to this parameter can dramatically amplify the performance of your Spark Streaming jobs, offering up to a 15x speed boost.

The Default Behavior — The Large Bucket Dilemma:

Imagine you’re at a water park, trying to fill a massive pool using several hoses. Each hose fills a large 128 MB bucket before emptying it into the pool. This is akin to Spark’s default behavior, where each core (or hose) processes data up to 128 MB before moving it further down the pipeline. While this method works, it’s not the most efficient, especially when dealing with numerous smaller files. The large bucket size could lead to slower fill times, underutilizing the hoses and delaying the pool’s completion if you can aquire more hoses(cores).

Real-World Implications — The Need for More Buckets:

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Canadian Data Guy

https://canadiandataguy.com | Data Engineering & Streaming @ Databricks | Ex Amazon/AWS | All Opinions Are My Own