Tech bloggers (myself included) tend to like writing about big issues, with massive impact, company’s reputation (or in extreme cases even very existence) at stake, etc. This adds dramatism to the story (and as an added bonus, helps us feel more important). I think it can also lead to a certain bias, making the IT community believe that only major issues matter. Whenever you spot a relatively harmless anomaly and try to find out more about it on a DBA forum, “is there an actual problem you’re trying to solve” is a very likely response. And if you honestly answer “not really”, you can expect a lecture on “obsessive tuning disorder” and a suggestion to stick to a simple principle, “ain’t broken don’t fix it”. I think this mentality was initially a sound reaction to some inquisitive minds trying to solve non-issues and occasionally creating issues out of nothing instead. When taking too far, however, this attitude becomes dangerous. Anomalies are important even without an immediate impact. Sometimes they are important even without any impact at all. In this post, I’d like to illustrate it with an example.

Continue reading “Performance monitoring and anomalies” →