I had the chance to work on an interesting case last week, and I thought I’d share what I think is a little known goodie from Percona Toolkit for MySQL called pt-query-digest.
One customer was suffering from periods of high load on their database server, leading to degraded application performance, and sometimes even short moments of downtime. As usual with these cases, we set up pt-stalk to trigger a capture if Threads_running went above a known ‘good’ value for this workload, so we would have lots of diagnostics information to review even if we couldn’t be logged in to the server at the time the problem happened.
As I began reviewing …
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