Cassandra to Redshift
real-time replication
TwinCommit replicates Apache Cassandra to Amazon Redshift in real time by reading the Cassandra transaction log and applying every committed change exactly once and in commit order. Use it to feed Redshift with live Cassandra data for analytics, AI and reporting, with no triggers or capture tables on the source.
Cassandra
log reader
commit-ordered · exactly-once
Redshift
native writer
How capture works on Cassandra
TwinCommit tails the CDC commit-log segments on every node, deduplicates replica writes, and orders mutations by write timestamp per partition.
Prerequisites
- ✓cdc_enabled: true in cassandra.yaml
- ✓WITH cdc = true on replicated tables
- ✓Agent sidecar or shared volume access to cdc_raw on each node
How apply works on Redshift
Micro-batches are written to S3 as Parquet, loaded with COPY into staging tables, and applied with MERGE in one transaction together with the checkpoint.
Requirements
- ✓An S3 staging bucket and IAM role for COPY
- ✓A database user with CREATE on the target schema
- ✓Network path to the cluster or workgroup endpoint
Setup
Set up Cassandra → Redshift in four steps
- 1
Prepare Cassandra
Run twincommit check. It verifies cdc_enabled: true in cassandra.yaml and the other prerequisites, and prints the exact fix for anything missing.
- 2
Point at Redshift
Add a target block for Redshift. 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: cassandra
contact_points: [cass-1, cass-2, cass-3]
cdc_dir: /var/lib/cassandra/cdc_raw
target:
type: redshift
host: analytics.123456789.us-east-1.redshift-serverless.amazonaws.com
database: dev
staging_bucket: s3://acme-twincommit-staging
iam_role: arn:aws:iam::123456789012:role/twincommit-copy
tables:
- source: sales.orders
- source: sales.customersCassandra to Redshift replication FAQ
How does TwinCommit replicate Cassandra to Redshift?
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TwinCommit reads changes from the Cassandra transaction log, buffers them per transaction, and applies each committed transaction to Redshift in commit order. Micro-batches are written to S3 as Parquet, loaded with COPY into staging tables, and applied with MERGE in one transaction together with the checkpoint.
Does Cassandra to Redshift replication need triggers or capture tables?
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No. TwinCommit reads the Cassandra log directly and creates no objects in the source database.
Is Cassandra to Redshift replication exactly-once?
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Yes. TwinCommit commits its checkpoint in the same Redshift transaction as the data, so a crash or restart never loses or duplicates a transaction.
What Cassandra versions are supported?
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Apache Cassandra 4.0, 4.1, 5.0 · DataStax Enterprise 6.8+ · Astra DB (target) · ScyllaDB (target).
Stream Cassandra to Redshift today.
Download the free Developer edition, or have one of our replication engineers walk you through a migration plan.