Cache All the Things

How to create a seamless experience for your customers and delight them using graphql and scaling it via different caching techniques. #GraphQLSummit2019

Transcript

1. Aditi Garg, Tech Lead Sandosh Vasudevan, Architect October 2019
2. TRULIA Discover a place you’ll love to live
6. Tech Stack
8. Platform
9. How we use GraphQL
10. GraphQL Repo Structure
11. Data Source Pattern
12. Rest Connector • Utility to make HTTP calls • Retries • Custom Metrics Key Terms: Axios, HTTP, Request
13. GraphQL Repo Structure
14. Crime Connector
15. 2 1
16. 3 2 4 5 6 7 8 2
17. 9 8
18. How we use GraphQL 1 Request 20+ Requests
19. Challenges
20. Challenges 1 Request 20+ Requests 3M Requests 60M+ Requests
21. HTTP Request DNS LOOKUP TCP CONNECT SEND WAIT TRANSFER
22. Do they ALL have to be realtime?
23. Reduce the number of outgoing requests. Goal
24. Layers GraphQL HTTP DNS
25. Solutions Data Loader Varnish DNS Cache
26. Solutions Data Loader Varnish DNS Cache
27. • N+1 problem • Resolvers unaware of each other GraphQL Resolvers
28. Query resolution
29. Query resolution
30. • N+1 problem • Resolvers unaware of each other GraphQL Resolvers
31. Generic data fetching layer utility • Batching • In memory caching Dataloader
32. Dataloader Batch Function
33. Dataloader Batch Function
34. • Batching • In memory caching per request Dataloader
35. Solutions Varnish Data Loader DNS Cache
36. Varnish • Application Accelerator • HTTP Cache • Reverse Proxy Key Terms: VCL, VMODS, TTL, Grace Mode
37. Varnish • Cache closer to GraphQL server • Default cache configuration • Can be overridden by response headers
40. Crime Connector
41. Crime Connector config
42. Varnish TTL GET 200 OK GET 200 OK GET 200 OK GET 200 OK GET 200 OK GET 200 OK GET 200 OK 200 OK 200 OK TTL GET GET
43. Grace Mode TTL GET 200 OK GET 200 OK GET 200 OK GET 200 OK GET 200 OK GET 200 OK GET 200 OK GET 200 OK TTL GET 200 OK Grace
44. Grace with errors TTL GET 200 OK GET 200 OK GET 200 OK GET 200 OK GET 200 OK GET 503 GET 503 GET 200 OK Grace GET GET 200 OK GET GET GET 200 OK
45. TTL Config
46. Header override
47. Header override
48. Solutions DNS Cache Varnish Data Loader
49. Reduce the number of outgoing HTTP requests Goal
50. Reduce the time spent in an HTTP request Stretch Goal
51. HTTP Request DNS LOOKUP TCP CONNECT SEND WAIT TRANSFER
52. HTTP Request DNS LOOKUP TCP CONNECT SEND WAIT TRANSFER
53. HTTP Request DNS LOOKUP TCP CONNECT SEND WAIT TRANSFER
54. DNS Server • Written in GO • Flexible with Plugins • Easy to configure CoreDNS
55. Core file
56. CoreDNS Cache Config
57. Solutions Data Loader Varnish DNS Cache
58. @adigarg94 @sandosh