Clickability: Scaling SaaS with MySQL and memcached

Clickability is the global leader in On Demand Web Content Management, offering the first and only commercially available, multi-tenant, Web content management and publishing platform on the market. This platform brings together multiple services into one integrated solution and delivers over 400 million pages per month across hundreds of customer websites. The demands of delivering a platform on this scale are magnified by the flexibility that Clickability’s platform provides customers in creating truly unique and innovative websites.

Building a SaaS platform requires application and infrastructure engineering that push beyond “enterprise scale” to “web scale”. MySQL and Memcached play a key role in scaling the Clickability platform. This presentation will tell the evolutionary story of the core architectural and technology components that have allowed the Clickability Platform to scale from 0 to 400 million pages delivered per month without changes to the core platform architecture.

Application platform – from 2 servers to 200

• use of Java
• distributed application architecture
• loose coupling around the data
• database connection management and load balancing

MySQL Databases – from 2 servers in one datacenter, to 30 servers across three datacenters

• early separation of database early to scale needs independently
• master/master for HA from day one
• master/slave for splitting reads and writes
• multi-datacenter replication for DR and HA
• MySQL 5.1 table partitioning benefits, including performance gain metrics

Multi-tiered Caching – performance, performance, performance

• Squid, Java Ehcache and Memcached
• “Cache clear” messaging subsystem
• Performance metrics/gains from adding these caching layers