MariaDB to Cassandra
real-time replication
TwinCommit replicates MariaDB to Apache Cassandra in real time by reading the MariaDB transaction log and applying every committed change exactly once and in commit order. Use it to serve MariaDB data from Cassandra at scale without dual writes, with no triggers or capture tables on the source.
MariaDB
log reader
commit-ordered · exactly-once
Cassandra
native writer
How capture works on MariaDB
TwinCommit reads the row-based binary log as a replica using MariaDB GTIDs, and follows Galera cluster failover automatically.
Prerequisites
- ✓binlog_format = ROW and binlog_row_image = FULL
- ✓REPLICATION SLAVE and BINLOG MONITOR grants
- ✓log_slave_updates on Galera nodes
How apply works on Cassandra
Batched upserts and deletes use the source commit timestamp as the Cassandra write timestamp, so replays are idempotent and newer data always wins.
Requirements
- ✓cdc_enabled: true in cassandra.yaml
- ✓WITH cdc = true on replicated tables
- ✓Agent sidecar or shared volume access to cdc_raw on each node
Setup
Set up MariaDB → Cassandra in four steps
- 1
Prepare MariaDB
Run twincommit check. It verifies binlog_format = row and binlog_row_image = full and the other prerequisites, and prints the exact fix for anything missing.
- 2
Point at Cassandra
Add a target block for Cassandra. 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: mariadb
dsn: ${SOURCE_DSN}
server_id: 4201
target:
type: cassandra
contact_points: [cass-1, cass-2, cass-3]
keyspace: replica
consistency: LOCAL_QUORUM
tables:
- source: SALES.ORDERS
- source: SALES.ORDER_LINES
exclude_columns: [INTERNAL_NOTES]MariaDB to Cassandra replication FAQ
How does TwinCommit replicate MariaDB to Cassandra?
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TwinCommit reads changes from the MariaDB transaction log, buffers them per transaction, and applies each committed transaction to Cassandra in commit order. Batched upserts and deletes use the source commit timestamp as the Cassandra write timestamp, so replays are idempotent and newer data always wins.
Does MariaDB to Cassandra replication need triggers or capture tables?
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No. TwinCommit reads the MariaDB log directly and creates no objects in the source database.
Is MariaDB to Cassandra replication exactly-once?
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Yes. TwinCommit commits its checkpoint in the same Cassandra transaction as the data, so a crash or restart never loses or duplicates a transaction.
What MariaDB versions are supported?
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MariaDB 10.6, 10.11, 11.x · Galera Cluster · SkySQL · Amazon RDS for MariaDB.
Stream MariaDB to Cassandra today.
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