1. SCALING
UBERMATT RANNEY

2. As of January 2016:
Uber Cities Worldwide: 361
Countries: 67
Employees: 5,400
Engineers: 1,700
US Driver Payments Jan-Oct 2015: $3.5B

5. UBER ENGINEERING
HISTORY

6. 2009-2010 Outsourced PHP + MySQL
Jan 2011 "dispatch" - Node.JS/MongoDB
Jan 2011 “API” - Python/SQLAlchemy/MySQL
Feb 2012 Dispatch swaps MongoDB for Redis
May 2012 Dispatch adds ON fallback
Jan 2013 First non-API Python services
Feb 2013 API switched to Postgres
Mar 2014 New Python services use MySQL
Mar 2014 Schemaless begins, must finish before pg collapse
Sep 2014 First Schemaless - trips out of Postgres
Aug 2015 Dispatch X.0 / Ringpop / Riak
Jan 2016 Go, Java, Cloud, More Abstractions

7. TECHNICALDEBT

11. Credit: NASA, ESA, and R. Thompson (Univ. Arizona)

12. Credit: NASA, ESA, and Z. Levay (STScI/AURA)

13. MICROSERVICES
Immutable?
Append Only?

14. Node.JS
Python
Go
Java

15. SCALING NODE

37. Getting out of the HTTP+JSON business
HTTP is slow, complex, and inconsistent
JSON is hard to validate, awkward in non-node
Thrift is OK, but generated code is bad

40. SERVICE DISCOVERY

42. Lots of services, lots of instances
Mostly Node.JS and Python
Call graph unknowable
Self-inflicted DoS
Cascading failures

48. load balancerservice A
service B
service B

49. load balancer
service A service B
service B

51. horizontal scalability
zipkin tracing
circuit breaking
rate limiting
failure testable
almost no configuration
as available as possible

52. overall latency ≥ latency of slowest component
1ms avg, 1000ms p99
use 1: 1% at least 1000ms
use 100: 63% at least 1000ms
1.0 - 0.99^100 = 0.634 = 63.4%
LATENCY

53. requeststhatareslow
0%
25%
50%
75%
100%
Processes Used
1 2 4 8 16 32 64 128 256 512 1024
p95 p99 p99.9

57. CULTURALCHANGES

58. FAILURE TESTING

59. RETRIES

60. partner app dispatch DC1
Location Updates
State Digest
dispatch DC2
Location UpdatesState Request

61. THANKS