ReadMeFeed / Community knowledge
Real questions. Useful conversations. Find the people who know your stack.
Developer tools · #apachespark
A decision guide for Spark broadcast joins: when the small side is small enough, how to tune autoBroadcastJoinThreshold safely, and how to verify the plan actually changed.
An architecture note on building exactly-once Spark Structured Streaming ETL: the minimal design (Kafka, checkpointing, idempotent sink), trust boundaries, failure behavior, and how to verify recovery actually works.
Stop fighting with shuffle partitions and data skew. Learn how Apache Spark's Adaptive Query Execution (AQE) dynamically optimizes query plans at runtime to eliminate stragglers.
Decide between manual spark.sql.shuffle.partitions tuning and Adaptive Query Execution (AQE) in Apache Spark, with a comparison table and Spark UI validation steps.
AQE can switch join strategies and split skewed partitions, but only at shuffle boundaries. A worked configuration, how to verify the plan changed, and where it stops helping.
When IoT devices send logs late, dashboards can become stale. Spark’s event‑time watermarks let you drop or keep late data automatically. This guide shows how to set up watermarks, a working example, and the trade‑offs you need to monitor.
A decision guide for picking the right join strategy on Spark DataFrames, with a comparison table, trade‑off analysis, and a PySpark example you can validate in the Spark UI.
Architecture note on enabling and operating Apache Spark Adaptive Query Execution: requirements, minimal config, trust boundaries, checks, failure modes, and redesign triggers.
Static query planning in Apache Spark often fails because the optimizer makes decisions using stale statistics. Adaptive Query Execution (AQE) solves this by re-planning the query plan at runtime based on actual data statistics collected during shuffle operations.