You manage a Ruby on Rails application that lives on a cluster of EC2 instances. Your website occasionally experiences brief, strong, and entirely unpredictable spikes in traffic that overwhelm your EC2 instances' resources and freeze the application. As a result, you're losing recently submitted requests from end users. You use Auto Scaling to deploy additional resources to handle the load during spikes, but the new instances don't spin-up fast enough to prevent the existing application servers from freezing. Which of the following will provide the most cost-effective solution in preventing the loss of recently submitted requests?
A. Keep a large EC2 instance on standby.
B. Increase the size of your existing EC2 instances.
C. Ask AWS support to pre-warm the Elastic Load Balancer.
D. Use Amazon SQS to decouple the application components and keep the requests in queue until the extra Auto-Scaling instances are available."

When making changes to optimize part of a processor, it is often the case that speeding up one type of instruction comes at the cost of slowing down something else. for example, if we put in a complicated fast floating-point unit, that takes space, and something might have to be moved farther away from the middle to accommodate it, adding an extra cycle in delay to reach that unit. the basic amdahl's law equation does not take into account this trade-off. a. if the new fast floating-point unit speeds up floating-point operations by, on average, 2ă—, and floating-point operations take 20% of the original program's execution time, what is the overall speedup (ignoring the penalty to any other instructions)? b. now assume that speeding up the floating-point unit slowed down data cache accesses, resulting in a 1.5ă— slowdown (or 2/3 speedup). data cache accesses consume 10% of the execution time. what is the overall speedup now? c. after implementing the new floating-point operations, what percentage of execution time is spent on floating-point operations? what percentage is spent on data cache accesses?