95% of My PySpark Job Finished in 4 Minutes. The Last Task Took 40. Here's Why.
I had a PySpark job joining a large transactions table with a customer dimension table. Nothing exotic — a standard join, then an aggregation. On pa…
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Why Spark Couldn't Read from Kafka: A Real Debugging Journey Across PySpark, Hadoop, Docker, and Kafka
I thought this would be a simple task. I already had a Python Kafka producer running. Kafka was up in Docker. The topic existed, and I could send a…
Why I stopped guessing at Spark and dbt config values
I've spent more than a decade building data pipelines, and the part nobody warns you about isn't the pipeline logic. It's the tuning. Executor memor…
Aligning Timeouts in Distributed Orchestration: Why Equal Airflow and Spark Limits Lead to Race Conditions
Recently, I reviewed an Airflow DAG where each task submits a single Spark job. I found this configuration: execution_timeout_minutes : 60 spark-job…
Broadcast Joins vs. Sort-Merge Joins: Choosing the Right Join Strategy in Apache Spark
In distributed data processing systems such as Apache Spark, joins are among the most expensive operations. The strategy used to join datasets can s…
How I debugged a Delta Lake DESCRIBE HISTORY timeout (and what's actually causing it)
If you have ever run DESCRIBE HISTORY on a Delta table that receives streaming data every 60 seconds and watched it either hang for hours or crash w…