Case studies
Real audits, anonymised
Write-ups of past customer engagements, with client names, people, hosts and data removed. Each one shows the evidence that was reviewed, what it pointed to, and the recommendations in the order they were given.
- Case study
Why a Galera cluster was slower than staging for an online shop
A three-node MariaDB Galera cluster behind a Magento shop: a handful of missing composite indexes carried a large share of query time, and the catalogue indexing process was written in a way that works against Galera.
- Case study
A MySQL server that spent half its time waiting for locks
A single, CPU-saturated MySQL server with 150 queries running at once. Missing indexes mattered, but the main finding was that two statements held most of the row locks everyone else was waiting for.
- Case study
A Galera cluster that became unstable when it was stretched to a second data centre
Seven Percona XtraDB Cluster nodes across two sites, barely loaded and mostly well configured, kept losing members. The error logs from both sides showed a flapping link between the data centres and Galera timeouts tuned for a local network.