What are some warnings signs I need bigger cloud computing instances?

Consider the costs

Many admins downsize their cloud instances compared to the in-house resources they would use to support a particular workload -- but this is a mistake.

When choosing an instance, consider its size. Larger cloud computing instances remove bottlenecks and allow apps to run more efficiently, which reduces the total instance count an organization needs. This offsets the higher price of a larger instance type, and should lead to overall savings, coupled with better runtimes.

Bursty workloads, however, require a little more attention. Larger cloud computing instances are likely the best choice for the baseline load, but admins should analyze workload spike patterns -- especially spike duration. To get the lowest overall total cost of ownership, it might be best to buy long-term instances, such as Amazon Elastic Compute Cloud Reserved Instances, for the baseline load, some larger instance types to support some of the bursts, and some smaller instances on the spot market to support remaining demand peaks.

Many admins downsize their cloud instances compared to the in-house resources they would use to support a particular workload -- but this is a mistake. The problem is that there is usually a minimum number of resources -- such compute, dynamic random access memory and networking -- for an app to run smoothly. Going below that threshold causes the app to spend major resources, such as thrashing files in and out of memory, to overcome bottlenecks. Admins can break up the workload to run on multiple instances to reduce size requirements, but that just means there is a new sweet spot, in terms of instance size, for admins to identify.