DBConvert StreamsAWS Aurora PostgreSQL CDC Setup Guide
1. Prerequisites
- AWS Aurora PostgreSQL cluster (version 2.x or higher)
- Proper IAM permissions to modify RDS parameters and security groups
- Source database with tables you want to replicate
2. Configure Aurora PostgreSQL Cluster
2.1 Enable Logical Replication
- Go to AWS RDS Console → Parameter Groups
- Create a new cluster parameter group or modify existing one
- Set the following parameter:
rds.logical_replication = 1
- Apply the parameter group to your Aurora cluster
- Reboot the cluster (this will cause downtime)
2.2 Verify Settings
After reboot, connect to your database and run:
sql
-- Check WAL level
SHOW wal_level; -- Should return 'logical'
-- Verify replication settings
SELECT name, setting
FROM pg_settings
WHERE name IN (
'wal_level',
'max_replication_slots',
'max_wal_senders',
'rds.logical_replication'
);
2.3 Grant Replication Privileges
sql
-- Grant replication privilege to your user
ALTER USER your_user WITH REPLICATION;
-- Grant table access
GRANT SELECT ON ALL TABLES IN SCHEMA public TO your_user;
3. Network Configuration
3.1 Security Group Setup
- Go to AWS RDS Console → Security Groups
- Select your Aurora cluster's security group
- Add inbound rule:
text
Type: PostgreSQL
Port: 5432
Source: Your application's IP/security group
3.2 Configure SSL (Recommended)
Download RDS SSL certificate:
bash
wget https://truststore.pki.rds.amazonaws.com/global/global-bundle.pem -O rds-ca.pem
4. Verify Replication Setup
4.1 Check Replication Slots
sql
-- List replication slots
SELECT * FROM pg_replication_slots;
-- List publications
SELECT * FROM pg_publication;
-- List subscriptions (if any)
SELECT * FROM pg_subscription;
4.2 Monitor Replication
sql
-- Check replication status
SELECT * FROM pg_stat_replication;
-- Check WAL sender processes
SELECT * FROM pg_stat_activity
WHERE backend_type = 'walsender';
5. Best Practices
5.1 Maintenance
sql
-- Clean up unused replication slots
SELECT pg_drop_replication_slot('slot_name')
WHERE NOT active;
-- Monitor slot lag
SELECT slot_name,
pg_size_pretty(pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn)) as replication_lag
FROM pg_replication_slots;
5.2 Error Handling
Common errors and solutions:
text
ERROR: logical decoding requires wal_level >= logical
→ Reboot cluster after setting rds.logical_replication = 1
ERROR: no pg_hba.conf entry for host
→ Check security group settings and SSL configuration
ERROR: must be superuser or have replication privilege
→ Grant necessary privileges to user