300-445 Question 195
Single answerA company is experiencing slow load times for its web application, and users are reporting frequent delays. The network team gathers browser waterfall data to diagnose the issue. Upon reviewing the waterfall, they observe a significant delay during the 'Time to First Byte' (TTFB) phase. What is the most likely cause of this delay?
- A
High server processing time due to inefficient backend code
- B
Large image files causing slow content loading
- C
Excessive redirects in the application
- D
Client-side JavaScript execution delays
Show answer and explanation
Correct answer: A
Explanation
Time to First Byte (TTFB) measures the duration between a user's request and the first byte of the response being received from the server. A high TTFB often indicates server-side issues such as inefficient backend code, database queries, or server resource constraints. Other factors, such as large image files or client-side delays, impact different parts of the loading process and are not directly responsible for high TTFB values.
- A. Correct.
High server processing time due to inefficient backend code is a common cause of increased TTFB. The server may take longer to respond to the client's request, leading to delays in the initial byte being received.
- B. Incorrect.
Large image files affect the content loading time after the initial response is received but do not directly impact the Time to First Byte (TTFB).
- C. Incorrect.
Excessive redirects can impact the overall load time but are not directly related to the TTFB phase, which measures the server's response to the initial request.
- D. Incorrect.
Client-side JavaScript execution delays occur after the server response is received and are not related to TTFB, which focuses on the server's response time.