[tcgv]

According to the article, the issue was caused by:

> "engineers had identified DNS resolution of the DynamoDB API endpoint for US-EAST-1 as the likely root cause"

Interestingly, we found matching errors in our own logs:

> System.Net.WebException

> The remote name could not be resolved: 'dynamodb.us-east-1.amazonaws.com'

Occurrences were recorded on:

- 2025-04-30

- 2025-05-29

- 2025-06-17

- Yesterday

We had logged this as a low-priority bug since previous incidents only affected our AWS testing environments (and never our production env which is on Azure). At the time, we assumed it was some CI/CD glitch.

It now seems that the underlying cause was this DNS issue all along, and only yesterday did it start impacting systems outside of AWS.

[znpy]

You just made me realize we had random DNS failures using ElastiCache last weeks... Totally randomly, some elasticache endpoints would fail to resolve within our VPC, bringing down some of our services.

At this point I wonder if it's related.