Key learnings from my refactor journey.
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The document outlines key learnings from a refactoring journey, highlighting issues like maintainability, testing, design, and performance. It discusses strategies such as incremental experimentation, effective use of caching, and proper indexing to improve system performance and code quality. The importance of understanding frameworks and avoiding common mistakes in coding and testing practices is also emphasized.
Key learnings from my refactor journey.
- 1. Key learnings from my refactor journey. Thiago Hora
- 2. The problem... ⬡ Maintainability ⬡ Hard to understand ⬡ Lack of test/lack of confidence to change ⬡ Hard to evolve ⬡ Poor performance
- 3. How we approach that 1. Testing 2. Design and Abstractions 3. Experimentation 4. Queries and Indexes 5. Caching 6. Frameworks 7. Outcome
- 4. Testing ⬡ Make sure you have coverage ⬡ Any test is better than no test ⬡ There is no difference between test code and production code ⬡ Refactoring also applies to test code
- 5. Design and Abstractions ⬡ Good code
- 6. Good code
- 7. Design and Abstractions ⬡ Good code ⬡ What does abstraction mean? ⬡ Where is it used? ⬡ What makes a good abstraction? ⬡ How to identify hidden abstractions? ⬡ You probably are going to fail at first try
- 9. Experimentation ⬡ Try different approaches ⬡ Apply changes incrementally ⬡ Use tools to measure the impact of each change ⬡ Leverage feature toggles/flags ⬡ Discuss and share the results within your team
- 10. Experimentation Try and monitor Number of time filter 1 is executed Number of elements removed by filter 1 Number of time filter 2 is executed Number of elements removed by filter 2 Latency before Latency after first switch Switching Back After Switch definitively
- 11. Queries and Indexes ⬡ What is an index?
- 12. What is an index
- 13. What is an index
- 14. What is an index
- 15. What is an index ⬡ An ordered subset of data that represents and provides the location of the register ⬡ B-tree
- 16. What is an index
- 17. What is an index
- 18. What is an index
- 19. What is an index ⬡ An ordered subset of data that represents and provides the location of the register ⬡ B-tree ⬡ Fast search/Logarithmic running-time
- 21. Of course not... ⬡ Indexes make the writes slower ⬡ Indexes take extra space
- 22. Queries and Indexes ⬡ What is an index? ⬡ What is an execution plan?
- 23. What is an execution plan? ⬡ It defines strategies to execute a query ⬡ Compare different possibilities ⬡ It does not guarantee the best option
- 24. What is an execution plan? ⬡ Type/Access Type ⬡ Scan strategies ⬡ Rows/Estimated rows affected
- 25. Type/Access Type
- 26. Type/Access Type ⬡ Const/eq_ref ⬡ Ref/Range/Index range scan ⬡ Index/Full index scan ⬡ All/Full table scan
- 27. Queries and Indexes ⬡ What is an index? ⬡ What is an execution plan? ⬡ Common mistakes
- 28. Common mistakes ⬡ Use functions on indexed columns ⬡ Index every column ⬡ Do not take into consideration the order of the columns (in case of composite indexes) ⬡ Sometimes only look for smaller row scan number is not enough ⬡ Delegate all the logic the SQL query ⬡ Use an inequality operator and break the
- 33. Caching ⬡ What is caching? ⬡ Why to use it? ⬡ Where to use it? ⬡ How to implement caching?
- 34. How to implement caching?
- 35. How to implement caching?
- 36. How to implement caching?
- 37. Caching ⬡ What is caching? ⬡ Why to use it? ⬡ Where to use it? ⬡ How to implement caching? ⬡ Trade-offs
- 38. Trade-offs ⬡ Local vs distributed ⬡ Cache strategies
- 39. Cache strategies(Mention the one we used) /Write around
- 40. Cache strategies
- 41. Cache strategies
- 42. Cache strategies
- 43. Trade-offs ⬡ Local vs distributed ⬡ Cache strategies ⬡ Cache Policies
- 46. Frameworks ⬡ What is a Framework ⬡ Why do we use them? ⬡ Common mistakes
- 47. Common mistakes ⬡ Lack of understanding of the nuances ⬡ Do not read the documentation ⬡ Do not follow GitHub or community involved
- 48. Framework Optimization Configuration 1. Disable dirty check in hibernate for read only resources a. Set direct in the hibernate session b. Use @Transaction(readOnly=true) in Spring
- 54. Outcome
- 55. Outcome
- 56. Thanks!
- 57. Links ⬡ https://www.slideshare.net/ChristianAntognini/indexes- structuresplitsandfreespacemanagementinternals-otw2014 ⬡ https://www.alibabacloud.com/blog/optimizing-mysql-composite-index-in-innodb_595057 ⬡ https://www.youtube.com/watch?v=HubezKbFL7E ⬡ https://www.percona.com/blog/2012/11/23/full-table-scan-vs-full-index-scan-performance/ ⬡ https://www.baeldung.com/spring-cache-tutorial ⬡ https://codeahoy.com/2017/08/11/caching-strategies-and-how-to-choose-the-right-one/ ⬡ https://techbeacon.com/app-dev-testing/basic-abstraction-techniques-what-code- reviewers-need-know ⬡ https://web.stanford.edu/~ouster/CS349W/lectures/abstraction.html ⬡ https://vladmihalcea.com/the-anatomy-of-hibernate-dirty-checking/ ⬡ https://vladmihalcea.com/spring-read-only-transaction-hibernate-optimization/ ⬡ https://www.baeldung.com/java-microbenchmark-harness ⬡ https://linux.die.net/man/1/ab#:~:text=ab%20is%20a%20tool%20for,installation%20is%20 capable%20of%20serving.