Flyway - Database Migrations Made Easy

We all take version control for granted. And it is, when it comes to code. On the database side, however schema evolution is often performed ad-hoc: a quick statement here, a little script there. The result: confusion and uncertainty. Has this update already been applied on this instance? Should we apply this other script first? Is our application going to run against this database?

No more! This is where database migration tools come to the rescue! We'll look at a popular open-source choice called Flyway. By the end of the session, you'll have a solid understanding of what it does, how it works and how to effectively integrate it into your project. We'll look at concepts and solutions. We'll tackle the hard problems and show you how this fits in a Continuous Delivery and Zero Downtime workflow. This will transform how you deal with your database, and you'll never look back.

Transcript

1. AXEL FONTAINE @axelfontaine axel@boxfuse.com Database Migrations made Easy
2. About Axel Fontaine • Founder and CEO of Boxfuse • Over 15 years industry experience • Continuous Delivery expert & trainer • Regular speaker at tech conferences • JavaOne RockStar in 2014 @axelfontaine
3. flywaydb.org
4. boxfuse.com
5. about questions
6. Who is using a relational database ?
8. Why should you use a relational database ? • ACID • Battle-tested reliability • Performance • Scaling up • Slice & dice data • Defer decisions
9. relational databases should be the default choice for new projects
10. What about scaling ???
11. Algorithms are for people who don’t know how to buy RAM. Clay Shirky
12. RAM is the new disk
13. The secrets of scaling • Buy RAM (it’s cheap!) • Keep LOBs out of the DB (only store a reference) • Only then look at techniques like sharding
14. Here is a small story
16. What about NoSQL ???
17. NoSQL databases are like divas They can be great, but you’d better know how to please them
18. Now let’s talk about database migrations ...
20. POLL: how are you doing database migrations? • Ad-hoc individual statements • Scripts (ad-hoc) • In-house tool (automated) • DB Migration tool • DB Migration API on App startup
21. APP
23. APP
24. APP Axel APP Prod APP Test APP CI APP Christian
25. SQL
26. SQL SQL SQL ? ? ?
27. flywaydb.org
28. 5 years old
29. 250 000+ downloads in 2014
32. With techniques such as continuous delivery becoming more mainstream, automated database migrations are a baseline capability for many software teams. While there are many tools in this space, we continue to recommend Flyway for its low-friction approach. Flyway has a vibrant open-source community behind it, and support for both traditional and cloud-based databases such as Amazon Redshift and Google Cloud SQL. -- ThoughtWorks
33. How does Flyway work ???
34. SQL SQL SQL ? ? ?
35. How does Flyway work ??? Empty DB
36. How does Flyway work ??? Empty DB Version 2 Version 1
37. What were Flyway’s design goals ???
38. It just works
39. Keeping it simple (saying no)
40. Convention over Configuration
41. No Lock-in
42. 0 required dependencies
43. 6 commands info clean migrate baseline validate repair
44. Demo
45. Supported databases
46. Supported execution platforms
47. Third party plugins
48. Basic architecture Migration Resolver API Database- specific support Metadata Table Migration Executor
49. Flyway flyway = new Flyway(); flyway.setDataSource(url, user, password); flyway.migrate();
50. mvn flyway:migrate <configuration> <url>…</url> <user>…</user> <password>…</password> </configuration>
51. <flyway:migrate url=“…” user=“…” password=“…”/>
52. flyway migrate -url=… -user=… -password=…
53. gradle flywayMigrate flyway { url = ‘…’ user = ‘…’ password = ‘…’ }
54. Demo
55. When should you migrate the database ???
56. Code and database share the same lifecycle So why risk having them not fit together?
57. Database migration should be performed on application startup
58. Flyway flyway = new Flyway(); flyway.setDataSource(url, user, password); flyway.migrate();
59. The Fear of DDL
60. VS DML DDL
61. Name Balance Homer 163 Marge 214 Bart 9 Lisa 25
62. VS DML DDL Name Balance Homer 0 Marge 0 Bart 0 Lisa 0 Name Homer Marge Bart Lisa From a business perspective the risk of DML and DDL is the same
63. Demo
64. A word about in-memory databases
65. Do you really want to test your code with a different query engine from the one you have in production???
66. Getting started
67. http://flywaydb.org/getstarted
68. Summary • Use a database migration tool
69. Summary • Use a database migration tool • Run it on application startup • Get started tomorrow 
70. flywaydb.org
71. Thanks ! AXEL FONTAINE @axelfontaine flywaydb.org boxfuse.com