CAS CAS Performance Optimization and Troubleshooting 3

Question 1

What is the purpose of a circuit breaker pattern in a CAS application's architecture?

Accepted Answer

To stop cascading failures by halting calls to a failing downstream service

Answer

The circuit breaker opens when a downstream service fails repeatedly, preventing the calling service from wasting resources on doomed requests.

Question 2

Which metric best measures the actual user-perceived performance of a CAS web application?

Accepted Answer

Time to first meaningful paint (FMP)

Answer

Time to first meaningful paint measures when users see actionable content, directly reflecting their perception of how fast the application loads.

Question 3

In CAS performance optimization, what is the primary goal of database connection pooling?

Accepted Answer

To reuse existing connections instead of creating a new one for every request

Answer

Connection pooling maintains a set of open connections that requests borrow and return, eliminating the overhead of creating and tearing down connections per request.

Question 4

A CAS application log shows frequent OutOfMemoryError exceptions. What is the most likely root cause?

Accepted Answer

Objects are being created faster than they are garbage collected or heap size is misconfigured

Answer

OutOfMemoryError occurs when the heap is exhausted, either due to a leak retaining objects or because the heap allocation is too small for the workload.

Question 5

Which approach best reduces I/O wait time when a CAS application writes large volumes of log data?

Accepted Answer

Buffering log writes and flushing asynchronously in batches

Answer

Asynchronous batched log writes reduce the frequency of disk I/O operations, freeing the application thread from waiting on each individual write.

(CAS) Certified Application Specialist Practice Test

(CAS) Certified Application Specialist Practice Test

CAS CAS Performance Optimization and Troubleshooting 3