Handling more demand.
VERTICAL SCALING
A larger resource: more processing, more memory.
Simple, and limited by the largest available size.
HORIZONTAL SCALING
More instances of the same thing, sharing the work.
More capable, and it requires the application to support it.
WHAT HORIZONTAL SCALING REQUIRES
Instances able to serve the same work Shared or synchronised data Sessions that work across instances
THAT LAST POINT
Sessions held on one instance break when a visitor reaches another.
AUTOMATIC SCALING
Capacity adjusting in response to demand.
WHAT TO BE CAREFUL WITH
Scaling in response to unwanted traffic, which costs real money No upper limit configured
WHAT TO SET
A maximum, always.
WHAT MOST SMALL BUSINESSES NEED
Neither.
A correctly sized resource with good caching handles far more than people expect.
WHAT TO DO FIRST
Improve efficiency. It is cheaper than capacity.
