System design

First no limitation

Then enroll the real world:

       Horizontal scaling

       Vertical Scaling

       Load balancer: server farm: increase security

       Big data: database partitioning(sharding): key sharding/vertical  lookup table

       Caching:

       Network:Latency, bandwidth, throughput

       Asynchronous processing/Queues

       Multi thread; map reduce

Scalability

Key considerations

Some pre:

Failures:

       Availability:

       Reliability:

       Read-heavy/write-heavy:

       Security:

Map reduce

Do work parallel

System Design