Numeric module ids in 4 shifted when a module was added, which changed the content of every chunk after it and invalidated caches for files that had not…
Forty gigabytes of logs a day and no answer to “is checkout slow”. Metrics, logs and traces answer different questions, and logs were doing all three badly.
Almost every MySQL tuning guide lists forty variables, and on a dedicated server the first one accounts for most of the difference. The rule of thumb is 60-70%…
A long-running PHP process keeps everything the framework touched, so a worker that runs forever accumulates memory whether or not there is a leak. The three limits are…
Fifty PHP-FPM workers all waiting on one slow upstream is a site that is down because of a service most of its pages do not use. Rejecting immediately…
Three pushes in ten minutes start three builds, and the first two are testing code that has already been superseded. Grouping on the ref rather than globally is…
An N+1 fixed by eager loading can be replaced by a memory problem, and a query-count assertion reports the page as healthy while it hydrates forty thousand objects.…