Caffeinated DNS Monitoring and the AT&T DNS Outage
To Cache or Not-to-Cache – that is the DNS Monitoring Question
Firstly, it is not generally well-known that external-based HTTP request-type website monitoring, like coffee at your local java joint, comes in different “grades” – cache-based and non-cache based. Dotcom-Monitor employs non-cached monitoring, which propagates through the full DNS process with each monitoring instance. Cache-based monitoring (used by many basic monitoring services) does not propagate through the DNS process and misses DNS issues.
How to Effectively Monitor for the next DNS Outage Situation
In the case of the AT&T DNS outage issue there are several key factors that help to speed up Time-to-Repair (TTR), or avoiding downtime.