A Hadoop to Databricks migration moves HDFS data, Hive tables, Spark and MapReduce jobs, Oozie workflows and Ranger or Sentry policies to a governed cloud lakehouse. Spark jobs usually move with small changes; MapReduce and Oozie logic is rebuilt as declarative pipelines and Lakeflow Jobs.
What we move
HDFS data, Hive tables, Spark and MapReduce jobs, Oozie workflows, Ranger and Sentry policies
Value after the move
Retire costly on-premise clusters and their upgrades
Keep Spark skills while dropping cluster babysitting
One governance model in Unity Catalog instead of Ranger and Sentry
How Legacy Hadoop maps to Databricks
Each component has a clear target on the Databricks Data Intelligence Platform.
Legacy Hadoop
Databricks
HDFS
Cloud object storage with Delta Lake tables
Hive tables and Hive Metastore
Delta tables in Unity Catalog
Spark on YARN
Serverless or job compute
MapReduce jobs
Spark code or Lakeflow Declarative Pipelines
Oozie workflows
Lakeflow Jobs
Impala queries
Databricks SQL warehouses
Ranger or Sentry policies
Unity Catalog permissions and audit
How we run the migration
Assess
Inventory every table, job, report and user. Map dependencies, find what is unused, and estimate effort and cost.
Output: Migration assessment and business case
Plan
Design the target lakehouse, governance and security. Group workloads into waves by value and risk.
Output: Target architecture and wave plan
Convert
Convert SQL and ETL with LakeBridge and our accelerators, then review and test the output.
Output: Converted, tested code per wave
Reconcile
Run old and new side by side and compare results table by table until they match.
Output: Signed-off reconciliation reports
Cut over and optimize
Move users in waves, retire the old system, then tune cost and performance.
Output: Decommission plan and FinOps baseline
We use Databricks LakeBridge for profiling, code conversion and reconciliation, alongside our own accelerators and engineer review of every critical path.
How long does a Hadoop to Databricks migration take?
It depends on the number of tables, jobs and users. We start with a short, fixed-scope assessment that inventories the cluster and produces a wave plan with effort and cost estimates.
Do we have to rewrite our Spark jobs?
Usually not. Most Spark jobs move with small changes. MapReduce jobs, Oozie workflows and custom scripts are the parts that need rewriting.
What happens to our Ranger or Sentry security policies?
We map them to Unity Catalog permissions, then add lineage and audit that Hadoop did not provide.