300-445 Question 194
Select 3A company is experiencing slow load times on their web application, and you have been tasked with diagnosing the issue. Upon analyzing the browser waterfall for a specific page, you observe the following: 1) A significant delay during the 'DNS Lookup' phase, 2) Multiple third-party scripts with long 'Waiting (TTFB)' times, and 3) A large image file taking an extended time to download. Based on this data, which actions would most likely improve the web application's performance?
- A
Implement a Content Delivery Network (CDN) to cache static assets closer to users.
- B
Optimize and compress the large image file to reduce its size.
- C
Reduce the number of third-party scripts loaded on the page.
- D
Switch to a different hosting provider to improve server hardware performance.
- E
Disable DNS prefetching to prevent unnecessary DNS lookups.
Show answer and explanation
Correct answers: A, B, C
Explanation
The browser waterfall analysis reveals three key issues: slow DNS lookup, long waiting times for third-party scripts, and a large image file taking too long to download. The appropriate solutions involve leveraging a CDN, optimizing the image file, and reducing third-party scripts to address these specific problems. Switching hosting providers and disabling DNS prefetching are not directly relevant or effective in resolving these issues.
- A. Correct.
Implementing a CDN can reduce latency by caching static assets like images and scripts closer to users, effectively addressing the slow load times caused by the large image file.
- B. Correct.
Optimizing and compressing the large image file will directly reduce its download time, improving the page load performance.
- C. Correct.
Reducing the number of third-party scripts will minimize the 'Waiting (TTFB)' times for those scripts and decrease overall page load time.
- D. Incorrect.
Switching to a different hosting provider might improve server hardware performance but does not address the specific issues identified in the browser waterfall analysis, such as DNS delays or third-party scripts.
- E. Incorrect.
Disabling DNS prefetching would likely increase DNS lookup delays rather than resolve them, making this an ineffective solution for the observed issue.