Let's be honest. AWS DMS looks simple on the surface, but the real challenges often show up mid-migration, leaving you scrambling. The official documentation can only take you so far. What you really need is advice from someone who's been in the trenches. ‍ That's exactly why we're hosting this webinar. Join our Mydbops expert, Arun, for a practical, no-fluff session on AWS Database Migration Service. He's spent countless hours using DMS for complex client migrations and has learned firsthand what works, what breaks, and what the manuals don't tell you. In this webinar, our speaker will break down: How DMS Actually Works Performance Tuning That Makes a Difference Real-World Migration Strategies That Work The Honest Truth: When Not to Use DMS Essential Security & Validation Tips Mydbops Managed Services specializes in taking the pain out of database management while optimizing performance. Since 2015, we have been providing top-notch support and assistance for the top three open-source databases: MySQL, MongoDB, and PostgreSQL. Our team offers a wide range of services, including assistance, support, consulting, 24/7 operations, and expertise in all relevant technologies. We help organizations improve their database's performance, scalability, efficiency, and availability. Contact us: info@mydbops.com Visit: https://www.mydbops.com/ #mydbops #database #webinar #dba #opensource #techtalk #live #devops #cloud #AWSDMS #DatabaseMigration #AWS #CloudComputing #DevOps #DMS

1. AWS DMS: Architecture, Best Practices, and Limitations
Presented by
Arun N, Mydbops
Mydbops My Webinar - 46
26th September 2025

2. Consulting
Services
Consulting
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Managed
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❏ Database Management and
Consultancy Provider
❏ Founded in 2016
❏ Assisted 800+ happy customers
❏ AWS partners
❏ PCI & ISO certified
About Us

3. ❏ AWS Data Migration Service Overview
❏ AWS DMS Architecture - Core Components
❏ Migration Strategies
❏ Real-world Use Cases
❏ Common Challenges
❏ Best Practices
❏ Performance Tuning
❏ Security Considerations
❏ Limitations
Agenda

4. AWS Data Migration Service Overview
❏ Migrates data with minimal downtime
❏ Support homogeneous and heterogeneous migration
❏ Same Database Engine (Homogeneous)
❏ Different Database Engine (Heterogeneous)
❏ Supports structured and unstructured schema migration from
source to target.
❏ AWS DMS handles data migration according to the selected mode.

5. AWS DMS Architecture – Core Components

6. AWS DMS Architecture

7. AWS DMS Components
❏ Replication Instance
❏ Source Endpoint
❏ Target Endpoint
❏ Data Migration Tasks
❏ Cloudwatch Metrics

8. AWS DMS: Migration Modes

9. AWS DMS Migration Modes
❏ Full Load:
❏ Full load migration to the target database initiated.
❏ CDC (Change Data Capture):
❏ Captures real-time changes from source
❏ Full Load + CDC:
❏ Initial full load followed by change data captured

10. ❏ Homogeneous and Heterogeneous migration
❏ On-prem to AWS RDS migrations
❏ Structure change by enabling partitioning on target.
❏ Transformation rules.
❏ Continuous data replication for disaster recovery
❏ Analytics data pipeline
❏ Reverse replication.
Real-world Use Cases

11. ❏ Full load may take longer time based on data size.
❏ Data type limitations
❏ Migrating LOB-heavy tables
❏ Latency between source and target
❏ Source & Target connectivity
Common Challenges

12. ❏ Pre-validate source and target configurations
❏ Ensure proper network connectivity & low latency
❏ Use dedicated replication source server
❏ Perform pre-assessment test before migration
❏ Monitor replication tasks regularly
Best Practices

13. ❏ Avoid schema changes during migration.
❏ Keep DMS transformations rules simple.
❏ Enable AWS Control Tables on target server.
❏ Binlog retention: Must be ≥ 24 hours.
Best Practices

14. AWS DMS: Performance Tuning

15. ❏ Enable parallel load for faster migration of large tables
❏ MaxFullLoadSubTasks = value
❏ Optimize commit rate and enable batch optimized for efficient data
transfer
❏ CommitRate = value
Performance Tuning

16. ❏ Use table partitioning to migrate large tables in manageable chunks
❏ Limited LOB mode is faster
❏ Keep DMS instance in same AZ
Performance Tuning

17. ❏ Variables that can be enabled at runtime.
❏ innodb_flush_log_at_trx_commit = 0
❏ innodb_change_buffer_max_size = 40–50%
❏ innodb_change_buffering = inserts
❏ innodb_flush_neighbors = 0
❏ sync_binlog = 0
❏ innodb_io_capacity / innodb_io_capacity_max
❏ Innodb_lru_scan_depth
Enable Innodb Variables On Target Server

18. ❏ Variables that require a server reboot.
❏ log_bin = OFF
❏ innodb_doublewrite = OFF
❏ innodb_adaptive_hash_index = OFF
❏ innodb_log_file_size = Larger value
❏ Disable Redo Log
Enable Innodb Variables On Target Server

19. How to choose right LOB size?

20. ❏ Identify tables containing LOB columns on the source (Q1).
❏ Retrieve the maximum LOB size per column (Q2).
Limited LOB Mode

21. ❏ Sum all maximum values across tables.
❏ Convert the total from bytes → Bytes/KB.
❏ Add a 10% buffer for safety.
❏ Use this final value in DMS Limited LOB Mode for optimal performance.
Limited LOB Mode

22. AWS DMS: Security Considerations

23. ❏ Grant only necessary privileges to the replication user
Security Considerations

24. ❏ Enforce strong passwords for database users
❏ Use SSL connections for secure data transfer between endpoints
❏ Apply required-privilege IAM roles and policies for DMS tasks
❏ Avoid public access
Security Considerations

25. ❏ Trigger,Views & Functions we must be create manually in target.
❏ Ongoing replication doesn’t handle DDL.
❏ Large data sets needs tuning and multiple DMS segregation.
❏ Binlog Configurations
❏ Binlog_format: ROW(required for full row-level replication).
❏ Binlog_checksum: NONE(to avoid replication issues).
❏ Binlog_row_image: FULL (captures all column data).
Limitations

26. https://docs.aws.amazon.com/dms/latest/userguide/Welcome.html
https://aws.amazon.com/dms/getting-started/
https://aws.amazon.com/blogs/database/aws-dms-best-practices-for-moving-large-tables
-with-table-parallelism-settings/
https://aws.amazon.com/rds/getting-started/
https://docs.aws.amazon.com/dms/latest/userguide/CHAP_BestPractices.html
https://repost.aws/knowledge-center/dms-replication-instance-storage-full
References

27. Thank you !