From 1 to 20 million users the technical story of BlaBlaCar

IPC Spring Berlin 2015

Transcript

1. the technical story of From 1 to 20 million users
2. Matthieu Moquet @MattKetmo web engineer at
3. Leader ride-sharing service Our goal is to become the 1st travel platform
4. Why this talk? ❖ History of the BlaBlaCar platform ❖ Overview our main technical choices ❖ Understand of our culture & methodologies
5. v1.0 2005–2006
6. The prototype
7. v2.0 (2008) – Plain PHP
8. 2008 2010 2011 2012 v2.0
11. Homemade framework + No code convention + Messy = Not maintainable in the long term
12. $  wc  -­‐l  lib.trip.php Longest method: 1000+ lines 3678
14. No tests
15. Going further will be a pain Hiring will be hard We need to change things
16. Refactor all the code
17. Symfony 2.0
18. Because community matters
19. Attract new talented 
 & motivated people
20. Separation of Concerns Dependencies Injection Integration & Unit tests etc. Embrace best practices
21. Update product design
23. Agility is our best strength
24. — Eberhardt Von Kuenheim « The big will not always eat the small, 
 but the fast ones will overtake the slow ones »
25. 10+ deployments per day
26. DEVOPS… before it was cool « if you break it you fix it »
27. Automation Automatize as much as possible to reduce the time between dev and prod
28. Simple development workflow Master Branch
29. git push origin feat-awesome Deploy on staging environment is as simple as
30. Staging env. for QA & product owners https://feat-awesome.staging.blablacar.com
31. Continuous Integration https://github.com/alexandresalome/behat-launcher
33. Localization Update translations on the fly
34. Frontend server Databases Backoffice Sync translations Update translations
35. Download last translations when app boot Update translations Mobile app CDN Backoffice
36. openl10n.io
37. Progressive Rollout ❖ Open new countries with v3 one by one ❖ It took about 2.5 years to run v3 everywhere ❖ Today we can deploy new features for a set of users (by attributes or random)
38. Monitoring
39. ELK
40. Monitoring
41. Departure to new horizons…
42. Opportunity to change backend But we still keep the same primary database
43. Database Updates Sync replication & No Master SPOF
44. Better archiving strategy
45. Photo Storage Don’t store static BLOB into MySQL. Use an elastic filesystem storage. MySQL AWS S3
46. elasticsearch ❖ Horizontally scalable ❖ Geo type index ❖ Aggregations
47. Varnish Fast reverse proxy cache 30% HIT/MISS Firemode to handle high traffic (TTL) Be careful with authenticated user blocks (Javascript is your friend)
48. SPDY (HTTP 2.0) Fast API calls for (compliant) mobile clients ngx_http_spdy_module
49. Asynchronous jobs Command Command Handlers Commands Queueing Ack
50. workers/      mail      sms      push      image-­‐resize      indexer      cache-­‐invalidation      elasticsearch-­‐indexation      trip-­‐publication      ... github.com/swarrot
51. Horizontal scalability
52. Event dispatcher Every business events is dispatched into RabbitMQ Easy to watch the events (in real-time or batchs)
53. Data Warehouse Log every business event into Hadoop user.register user.edit_bio user.left_rating user.post_trip ...
54. user.register user.edit_bio user.left_rating user.post_trip ... user.register user.post_trip ... Real-Time dashboard Log every business event into Elasticsearch
55. Such performances. Many users. Wow.
56. How to serve the product worldwide?
57. Datacenter centric One datastore to rule them all? It ain’t gonna work. ?? ??
58. Monolithics Micro-Services
59. Today we are mainly Monolithics But we would love using more Micro-Services Easier to deploy Development workflow Legacy database Smaller teams Faster deployments Easier to scale out
60. Gateway Principles (Clean Architecture) Decouple models (not db) Isolate business & data accesses (in the Monolytics to better decouple in micro services) Restrictive rules Enter the
61. Gateway RegisterUser PublishTrip PostMessage UpdateBio PostRating Users Messages Trips Business Data
62. But this is a long term project…
63. caching In the short term we invested on
64. Points of presence & Varnish
65. Mobile First
66. But how to cache the API? GET  /api/trips?from=Paris&to=Berlin   Authorization:  Bearer  7c82e855b0415f27bd92d   HTTP/1.1  200  OK   {          "trips":  [...]   }
67. { Reverse proxy is useless if only the app knows the authorizations Reverse Proxy Client User Scopes Access Token
68. Let the reverse proxy check authorization directly Reverse Proxy But here is a latency problem
69. Use of stateless token Reverse Proxy So we don’t need a database anymore
70. Json Web Token
71. What mobile apps send GET  /api/trips?from=Paris&to=Berlin   Authorization:  Bearer  eyJhbGciOiJIUzI1NiI...
72. What backend servers receive GET  /api/trips?from=Paris&to=Berlin   X-­‐Auth-­‐User:  1337   X-­‐Auth-­‐Client:  android   X-­‐Auth-­‐Scope:  user_info,messages
73. App gets an Access Token from the origin Reverse Proxy App submit request with Access Token Reverse Proxy transform Access Token header into custom X-Auth headers
74. Cachable response HTTP/1.1  200  OK   Content-­‐Type  application/json   Vary:  X-­‐Auth-­‐Scope   ! {  "trips":  [  ...  ]  }
75. Long term solution to deliver data close to the client
76. ❖ Manage massive amounts of data ❖ High Availability ❖ Multi Datacenter replication
77. ‣ Know the read requests before creating your data models ‣ Create as many tables (KeySpaces) than you have views ‣ Denormalize the data (no join allowed)
78. CQRS & Event Sourcing ❖ Separate Read & Write ❖ Eventual consistency ❖ But hard to do with legacy software / database See talk PHPTour 2015 at moquet.net
79. C* C* C* Primary Data C* Read Data User post message Endpoint
80. Messaging (micro) service Expose an HTTP API
81. 2008 2012 2013 2014 2015 2016 2 6 15 30+ … ?
82. blablatech.com We’re hiring Follow us
83. Thank You Slides available at moquet.net/talks/ipc-2015-blablacar Leave feedbacks at @MattKetmo