Elite Bug Squashing
Download as PPTX, PDF2 likes156 views
The document discusses debugging techniques at different levels from basic to advanced. It begins with level 1 debugging which involves tools like echo and var_dump and strategies like researching issues online and asking peers for help. Level 2 debugging introduces logging, advanced local environments, monitoring and profiling tools. It discusses strategies like replicating issues and eliminating variables. Level 3 involves preventative techniques like defensive programming, code quality tools, and ensuring a learning culture. The document also provides an example case study of randomly occurring cache corruption that was solved through these debugging steps.
More Related Content
What's hot (19)
Similar to Elite Bug Squashing (20)
![Static Code Analysis PHP[tek] 2023](https://cdn.slidesharecdn.com/ss_thumbnails/staticcodeanalysisphptek2023-230517122556-f35bc9a2-thumbnail.jpg?width=560&fit=bounds)
Recently uploaded (20)
Elite Bug Squashing
- 3. Technical Director, Space 48 @Tonegolf71 @Space48ers Tony Brown
- 4. Mage Titans UK – Developer Conference 10th November 2018 @MageTitans Tony Brown
- 5. Cache corruption Randomly occurring, site down
- 6. Random cache corruption • A pre-launch Magento 2 site • Would randomly end up with exceptions • The site would be unavailable until… • …a cache clear would resolve the issue
- 7. Random cache corruption • A pre-launch Magento 2 site • Would randomly end up with exceptions • The site would be unavailable until… • …a cache clear would resolve the issue Where do you begin?
- 8. Level 1 Finding your debugging feet
- 9. Debugging starts on day 1 • Debugging is an integral part of coding • I started with 20% coding, 80% debugging • We should strive for the opposite!
- 10. Types of debugging • Bugs during development • Bugs that are “live” – Feature broken – Performance issues – Site down
- 11. Impact of bugs • The further along the development lifecycle that bugs appear, the greater the impact.
- 12. Level 1 Tooling • Echo / var_dump / print_r … die()
- 13. Level 1 Strategy: Research • The majority of problems you will face have been solved already.
- 14. Level 1 Strategy: Research • The majority of problems you will face have been solved already. • Opensource community rocks! – Stack exchange – Forums – Github – Contribute if you can!
- 15. Level 1 Strategy: Ask your peers • You shouldn’t be fearful of leaning on your team
- 16. Level 1 Strategy: Ask your peers • You shouldn’t be fearful of leaning on your team • Articulating a problem (even to someone non-technical) can result in your brain sparking off new ideas – They may have ideas or even the solution!
- 17. Random cache corruption • Google revealed it to be a config cache issue – But the recommended resolution didn’t apply
- 18. Random cache corruption • Google revealed it to be a config cache issue – But the recommended resolution didn’t apply • No-one in the team had seen the issue before
- 19. Random cache corruption • Google revealed it to be a config cache issue – But the recommended resolution didn’t apply • No-one in the team had seen the issue before • Collaboration did happen, which accelerated progress
- 20. Level 2 Walking the debugging walk
- 21. Level 2 Tooling • Logging
- 22. Level 2 Tooling • Logging Why is the hard drive nearly full?!
- 23. Level 2 Tooling • Logging • Advanced local environments
- 24. Level 2 Tooling • Logging • Advanced local environments • Monitoring - New Relic
- 25. Level 2 Tooling • Logging • Advanced local environments • Monitoring - New Relic • Profiling – Blackfire
- 26. Level 2 Strategy • Can I replicate the issue?
- 27. Level 2 Strategy • Can I replicate the issue? • What has changed?
- 28. Level 2 Strategy • Can I replicate the issue? • What has changed? • Are there any errors?
- 29. Level 2 Strategy • Can I replicate the issue? • What has changed? • Are there any errors? • Eliminate as much as possible at each step
- 30. Level 2 Strategy • Can I replicate the issue? • What has changed? • Are there any errors? • Eliminate as much as possible at each step • Protect through process: – Code Reviews – QA Function – Automated tests where possible
- 31. Random cache corruption • Couldn’t replicate it locally
- 32. Random cache corruption • Couldn’t replicate it locally • What had changed? – Recently gone to multi-server setup
- 34. Multi-server setup Cluster RedisDB Servers Web 1 Web 3Web 2 Admin Load Balancer
- 35. Random cache corruption • Couldn’t replicate it locally • What had changed? – Recently gone to multi-server setup • Eliminate as much as possible – When set to single server, the issue disappeared
- 36. Multi-server setup (restricted) Cluster RedisDB Servers Web 1 Web 3Web 2 Admin Load Balancer
- 37. Random cache corruption • Couldn’t replicate it locally • What had changed? – Recently gone to multi-server setup • Eliminate as much as possible – When set to single server, the issue disappeared • Put logging in place to capture state – Found that the config cache was getting zapped repeatedly
- 38. Level 3 Clear vision and prevention
- 39. Level 3 Tooling • Xdebug
- 40. Level 3 Tooling • Xdebug • Static analysis for quality / best practice – Mess Detector, Copy paste detector
- 41. Level 3 Strategy • Defensive Programming
- 42. Level 3 Strategy • Defensive Programming • Conscious structure of code – SOLID principles
- 43. Level 3 Strategy • Defensive Programming • Conscious structure of code – SOLID principles • Tight feedback loops
- 44. Level 3 Strategy: Culture of learning – Reduce FEAR! • Mistakes and failures are learning opportunities • Ensure people understand they will be supported • Put in place processes to reduce risk and protect people • Actively encourage people to seek improvements
- 45. Random cache corruption • Used Xdebug to find it was a 3rd party module zapping the cache
- 46. Random cache corruption • Used Xdebug to find it was a 3rd party module zapping the cache • Used Redis Monitor to observe the config cache being written to – This revealed that when it was written to with bad data, it always came from the admin IP address
- 47. Random cache corruption • Used Xdebug to find it was a 3rd party module zapping the cache • Used Redis Monitor to observe the config cache being written to – This revealed that when it was written to with bad data, it always came from the admin IP address The old pre-production environment still existed!
- 48. Multi-server setup Cluster RedisDB Servers Web 1 Web 3Web 2 Admin Load Balancer
- 49. Multi-server setup (pre-prod!!) Cluster RedisDB Servers Web 1 Web 3Web 2 Admin Load Balancer Pre-prod
- 51. Bonus Level: The Pomodoro Technique • 25 minute cycles
- 52. Bonus Level: The Pomodoro Technique • 25 minute cycles • At each break, question progress and approach
- 53. Bonus Level: The Pomodoro Technique • 25 minute cycles • At each break, question progress and approach • Encourages focus and reduces chances of going “down the rabbit hole”
- 54. Thank you! • Any Questions? Manchester 10th November 2018 @MageTitans @tonegolf71