Tag: DNS issues

Akamai DNS Outage – Akamai Technologies Goes Down Many Clients Offline

Aug. 1, 2013 – Dotcom-Monitor tracked an Akamai DNS outage today.

Dotcom-Monitor clients that utilize Akamai may have received error messages associated with the Akamai DNS outage lasting from 5-7 minutes starting at approximately 11:01 am CDT.

The Akamai DNS outage, though brief, is only one of several high-profile DNS outage issues that has occurred in the past year. In the recent past, Dotcom-Monitor has detected several high-profile DNS outages for its clients, including…

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DNS Monitoring Improves Web Site Speed and Reliability – Part 2

Dotcom-Monitor uses a non-cache DNS monitoring solution with high frequency monitoring that propagates DNS queries to the root name servers. That means a DNS issue will be identified quickly, as opposed to being masked for days as it might be with a cached monitoring approach. When monitored properly, using a non-cache method, an error is quickly identified so the designated workaround, like a DNS failover, can be implemented.

Dotcom-Monitor non-cached DNS monitoring (unlike some other cache-based DNS monitoring solutions) also provides diagnostics with an automated trace-route as soon as a DNS problem is detected. This means less time investigating the problem and much faster mean-time-to-repair (MTTR). The Dotcom-Monitor DNS monitoring solution also allows website owners to spot trends so that small DNS issues can be addressed before they become big DNS problems.

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DNS Monitoring Improves Web Site Speed and Reliability – Part 1

The only way to know how well or how reliably DNS servers perform is to make consistent, regular objective tests and measurements over time. While DNS servers can be verified manually, that is not a practical solution. Manually checking the DNS servers a few times a week, or even a few times a day, simply does not provide enough data to accurately judge performance, nor does it quickly alert website owners to problems. Automatic DNS monitoring gives website owners the information needed.

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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.

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Doing DNS Monitoring Right: The AT&T DNS Outage

Doing DNS Monitoring Right: The AT&T DNS Outage: The AT&T domain name server (DNS) outage of Aug. 15, 2012 exemplifies why a “non-cache based” method for monitoring of websites is important for mission-critical websites. Firstly, a bit of a review. The most common, basic form of website monitoring is conducted using a synthetic browser (not an actual browser), which connects to the target server via an HTTP request process. A number of server-focused processes, such as the availability of the target server, the time it takes to load the HTML file for the website from the server, and the capability to detect keywords within the HTML file are checked via the use of a synthetic browser using an HTTP request process.

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