Google Cloud Profiler Description
It is not easy to understand the performance of production systems. It is often difficult to measure the performance of production systems in test environments. Although micro benchmarking is possible in some cases, it will not replicate the workload or behavior of a production environment. Continuous profiling of production system is a great way to find out where resources like memory and CPU cycles are being used by a service in its working environment. Profiling is an extra load on the production system. However, profiling must not add any additional load to the production system. Cloud Profiler is a statistical profiler with low overhead that continuously collects information about CPU usage and memory allocation from your production applications. It assigns that information to the source code which generated it.