MongoDB to Db2
real-time replication
TwinCommit replicates MongoDB to IBM Db2 in real time by reading the MongoDB transaction log and applying every committed change exactly once and in commit order. Use it to migrate or continuously mirror MongoDB into Db2 with zero downtime, with no triggers or capture tables on the source.
MongoDB
log reader
commit-ordered · exactly-once
Db2
native writer
How capture works on MongoDB
TwinCommit opens change streams on replica sets and sharded clusters, persists resume tokens with the checkpoint, and keeps multi-document transactions intact.
Prerequisites
- ✓Replica set or sharded cluster (change streams need an oplog)
- ✓changeStream and find privileges on watched databases
- ✓Pre- and post-images enabled for full before/after values (optional)
How apply works on Db2
Array MERGE statements committed in the same unit of work as the TwinCommit checkpoint.
Requirements
- ✓Archive logging enabled (LOGARCHMETH1)
- ✓DATA CAPTURE CHANGES on each replicated table
- ✓A primary key or unique index on each replicated table
- ✓DBADM (or SYSADM) for the capture user
Setup
Set up MongoDB → Db2 in four steps
- 1
Prepare MongoDB
Run twincommit check. It verifies replica set or sharded cluster (change streams need an oplog) and the other prerequisites, and prints the exact fix for anything missing.
- 2
Point at Db2
Add a target block for Db2. 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: mongodb
uri: ${MONGODB_URI}
target:
type: db2
database: REPLDB
user: ${DB2_TARGET_USER}
password: ${DB2_TARGET_PASSWORD}
tables:
- source: sales.orders
- source: sales.customersMongoDB to Db2 replication FAQ
How does TwinCommit replicate MongoDB to Db2?
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TwinCommit reads changes from the MongoDB transaction log, buffers them per transaction, and applies each committed transaction to Db2 in commit order. Array MERGE statements committed in the same unit of work as the TwinCommit checkpoint.
Does MongoDB to Db2 replication need triggers or capture tables?
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No. TwinCommit reads the MongoDB log directly and creates no objects in the source database.
Is MongoDB to Db2 replication exactly-once?
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Yes. TwinCommit commits its checkpoint in the same Db2 transaction as the data, so a crash or restart never loses or duplicates a transaction.
What MongoDB versions are supported?
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MongoDB 5.0–8.x · MongoDB Atlas · replica sets and sharded clusters.
Stream MongoDB to Db2 today.
Download the free Developer edition, or have one of our replication engineers walk you through a migration plan.