Scaling

• https://www.youtube.com/watch?v=RfBiuFYvR4w

Vertical Scaling

• aka scaling up

• We increase the hardware of the servers
• Load balancing not required
• Single point of failure
• Inter process communication which is fast
• Consistent
• Hardware limit

Horizontal Scaling

• aka shared-nothing architecture or scaling out
• We increase the number of servers to handle large load
• Load balancing is required
• Benefits
  • Comparatively cheap
  • Can achieve high reliability through redundancy
  • Resilient (recover from failures)
  • Scales well when users increase
• Disadvantages
  • Network calls which is slow
  • Data inconsistency

Elastic

• automatically add computing resource when load increases