Migration

Leaving Hadoop: a step-by-step path to Databricks

Hadoop clusters are expensive to keep alive and hard to staff. Here is how to move without breaking the reports that depend on them.

Cover illustration: Leaving Hadoop: a step-by-step path to Databricks
Short answer

To leave Hadoop for Databricks, inventory the cluster, retire unused data, move Spark jobs with small changes, rewrite MapReduce and Oozie as declarative pipelines and Lakeflow Jobs, map Ranger or Sentry policies to Unity Catalog, and reconcile before switching users.

Key takeaways

  • Spark moves easily; MapReduce and Oozie need rewriting.
  • Ranger and Sentry map to Unity Catalog.
  • Move high-value workloads first.

Many enterprises still run important workloads on Hadoop. The clusters are often near end of support, upgrades are risky, and the engineers who built them have moved on.

Why move now

  • Hardware and support renewals keep coming.
  • Security policies live in Ranger or Sentry, separate from everything else.
  • Adding modern AI on Hadoop is slow and fragile.

What moves easily

Spark jobs usually move with small changes. Hive tables convert to Delta tables. HDFS data copies to cloud object storage.

What needs more care

MapReduce jobs, Oozie workflows and custom scripts need rewriting. We turn them into declarative pipelines and Lakeflow Jobs, which are easier to test and monitor.

Security and governance

We map Ranger or Sentry policies to Unity Catalog, then add lineage and audit that Hadoop never had.

Our advice

Do not lift everything. Retire unused data and jobs first. Move the most valuable workloads early, so the business sees benefits before the last cluster is switched off.

About the author

NeuralShore Engineering, Databricks delivery team

Databricks architects, data engineers and AI engineers at NeuralShore, DLytica’s Databricks delivery company. Leadership comes from IBM data and AI architecture.

FAQ

Frequently asked questions

What moves easily from Hadoop to Databricks?

Spark jobs, Hive tables (as Delta tables) and HDFS data (to cloud object storage).

What needs rewriting?

MapReduce jobs, Oozie workflows and custom scripts, which become declarative pipelines and Lakeflow Jobs.

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