PostgreSQL to Spark
real-time replication
TwinCommit replicates PostgreSQL to Apache Spark in real time by reading the PostgreSQL transaction log and applying every committed change exactly once and in commit order. Use it to process every committed PostgreSQL change in real time with Spark, with no triggers or capture tables on the source.
PostgreSQL
log reader
commit-ordered · exactly-once
Spark
native writer
How capture works on PostgreSQL
TwinCommit uses a logical replication slot with the built-in pgoutput plugin, so there is nothing to install on the server.
Prerequisites
- ✓wal_level = logical
- ✓REPLICATION privilege
- ✓Primary key or REPLICA IDENTITY FULL
How apply works on Spark
The TwinCommit Spark connector exposes each pipeline as a Structured Streaming source with offsets mapped to log positions, so your jobs get exactly-once semantics with Spark checkpoints.
Requirements
- ✓The twincommit-spark connector JAR on the driver class path
- ✓Network access from the driver to the TwinCommit change feed endpoint
Setup
Set up PostgreSQL → Spark in four steps
- 1
Prepare PostgreSQL
Run twincommit check. It verifies wal_level = logical and the other prerequisites, and prints the exact fix for anything missing.
- 2
Point at Spark
Add a target block for Spark. TwinCommit can generate target DDL with twincommit ddl -apply.
- 3
Snapshot
twincommit snapshot copies each table under a brief share lock and records the exact log position.
- 4
Stream
twincommit run streams every committed change from that position, exactly once and in commit order.
source:
type: postgres
dsn: ${SOURCE_DSN}
slot: twincommit
target:
type: spark
listen: 0.0.0.0:7443
tls: true
tables:
- source: SALES.ORDERS
- source: SALES.ORDER_LINES
exclude_columns: [INTERNAL_NOTES]PostgreSQL to Spark replication FAQ
How does TwinCommit replicate PostgreSQL to Spark?
+
TwinCommit reads changes from the PostgreSQL transaction log, buffers them per transaction, and applies each committed transaction to Spark in commit order. The TwinCommit Spark connector exposes each pipeline as a Structured Streaming source with offsets mapped to log positions, so your jobs get exactly-once semantics with Spark checkpoints.
Does PostgreSQL to Spark replication need triggers or capture tables?
+
No. TwinCommit reads the PostgreSQL log directly and creates no objects in the source database.
Is PostgreSQL to Spark replication exactly-once?
+
Yes. TwinCommit commits its checkpoint in the same Spark transaction as the data, so a crash or restart never loses or duplicates a transaction.
What PostgreSQL versions are supported?
+
PostgreSQL 13–18 · Amazon RDS and Aurora · Azure Flexible Server · Cloud SQL · AlloyDB.
Stream PostgreSQL to Spark today.
Download the free Developer edition, or have one of our replication engineers walk you through a migration plan.