Today we continue our discussion on the AWS papers in software architecture which suggests five pillars:
- Operational Excellence for running and monitoring business critical systems.
- Security to  protect information, systems, and assets with risk assessments and mitigation strategies.
- Reliability to  recover from infrastructure or service disruptions
- Performance Efficiency to ensure efficiency in the usage of resources
- Cost Optimization  to help eliminate unneeded cost and keeps the system trimmed and lean.
The guidelines to achieve the above pillars include:
1. Infrastructure capacity should be estimated not guessed
2. Systems should be tested on production scale to eliminate surprises
3. Architectural experimentation should be made easier with automation
4. There should be flexibility to evolve architectures
5. Changes to the architecture should be driven by data
6. Plan for peak days and test at these loads to observe areas of improvement
We looked at the Operational Excellence, Reliability and security pillar and we reviewed the associated best practices.
#codingexercise
Find the nth multiple of k in Fibonacci Series
solution 1 : iterate through the Fibonacci Series testing and counting success
solution 2: Fibonacci multiples of a number are periodic. depending on k determine the period and hence the position of the result.
int GetNthMultipleFibonacci (int k, int n)
{
int multiple = -1;
for (int I = 0; I  < int_max; i++)
{
if (GetFibonacci (i) % k == 0){
    multiple = i + 1;
    break;
}
}
if (multiple == -1) return -1;
int position = n * multiple;
return GetFibonacci (position);
}