Scaling Hailo in the cloud

@davegardnerisme

Cloud Expo EuropeJanuary 2013

Hailo is the taxi app. Use Hailo to get a black cab wherever you are, whenever you want.

• The world’s highest-rated taxi app - over 7,000 five-star reviews

• Over 300,000 registered passengers

• A Hailo hail is accepted around the world every 5 seconds

• Hailo is growing (30%+) every month

• Became the largest taxi network in all of Ireland within two months of launch

“I come to use clouds, not to build them...”Adrian Cockcroft

http://bit.ly/WM4g2Z

Hailo runs on AWS. AWS allows us to grow rapidly.

• 2 regions

• 6 availability zones

• We use some AWS services: ELB, Route53 DNS, EBS

Going global…

DC 1

DC 2

DC 5

DC 4

DC 3

DC 6

Services(C*, ZK..)

ELB

Route53 latency-based DNS

eu-west-1

API layer

Web service

Services(C*, ZK..)

Services(C*, ZK..)

Web service

Web service

Web service

Services(C*, ZK..)

ELB

us-east-1

API layer

Web service

Services(C*, ZK..)

Services(C*, ZK..)

Web service

Web service

Web service

We favour technologies that are:

• distributed

• resilient

• operationally simple

• Cassandrafor distributed primary storage

• Zookeeperfor distributed locking

• Acunu Analyticsfor distributed real-time analytics

• NSQfor distributed queuing

Our C* usage:

• Two global clusters spanning 2 regions and 6 AZs

• Use cases include customer records, job history and more

Our AA usage:

• Main event stream is location updates from drivers (500/sec)

• Can aggregate in real-time to answer questions such as“how many drivers active in last 10 minutes?”

The key point is to keep services stateless and use specific tools for specific jobs:

storage, search, analytics, coordination

(makes it easier to scale)

Next steps

• Expansion, expansion, expansion

• NYC, Tokyo up next including third DC in Asia