Problems with dns resolution

Question

Summary

Starting from March 1st, we began experiencing DNS-related issues in the United States and Spain. Approximately 2% of users encountered a "connection reset" error when attempting to download images from the CDN.

Technical Details

• We have three CNAME records configured in Azure DNS, pointing to different CDN servers.
• The issue is observed across all three CNAME records.
• Our system downloads images using a round-robin method to ensure users can switch to different CDN servers if one fails.
• After noticing the issue, we ve added the domains referenced by Azure DNS.
• We observed that when downloading images via Azure DNS, we get a connection reset error.
• However, when accessing the same images directly (bypassing Azure DNS), the downloads work fine.
• We tested alternative CDN providers (Amazon, Bunny, Gcore) and found no issues.

Findings

• Using a process of elimination, we identified Azure DNS as the likely cause of the problem.
• Further investigation revealed that, starting from March 1st, a new HTTP status code 303 appeared in our logs.

Impact

• Users are playing the game without understanding what is happening.
• At the moment, we cannot provide additional detailed logs.

Next Steps

• Further investigation is required to determine the root cause of the DNS-related connection resets.
• Need to understand why the new 303 status code appeared after March 1st.
• Consider reaching out to Microsoft Azure support for assistance.