Tendril is a tool for analytics and performance tuning of the MariaDB servers, developed by Springle (with features added in an ad-hoc fashion as required) and used by the DBA team. For security reasons it is only accessible to people with NDA.
- Front end (vanilla PHP) runs on einsteinium.
- Backend database presently on db1011.eqiad.wmnet using MariaDB event scheduler and FEDERATEDX engine.
- Uses a pull method for monitoring with one watchdog database client connection to each host.
- Entirely and intentionally separate from ganglia and mediawiki-config to allow sanity checks both ways.
- Complements Ishmael for query tuning.
- Uses Labs LDAP for authentication (restricted to people with NDA).
It houses a lot of functionality, but here are a few highlighted features:
There are many different report views, such as:
- Slow queries. E.g. Slow queries from MediaWiki requests, slow analytics queries (from user 'research')
- An ad-hoc cluster-wide INFORMATION SCHEMA view (mostly standard schema plus server_id field).
- Cluster-wide query process list close to real time (10s intervals).
Based on actual reported configuration (no dependence on coredb or wmf-config/db-eqiad.php)
Information about each database host (e.g. IP, RAM, uptime) and interactive graphs and charts indicating their recent query activity and various InnoDB statistics.
Also linked to from most other reports.