TAF 4.0: MariaDB generates a user properties file to reproduce every test

MariaDB Foundation announced on 2 October 2026, on the official mariadb.org blog, a new feature of TAF 4.0 (Test Automation Framework): the automatic generation of a user properties file that captures the exact configuration used in each test run. For anyone benchmarking MariaDB, MySQL or PostgreSQL and needing to reproduce a result on another machine, this is the difference between redoing the test and guessing at it.\n\n## What changes\n\nUntil now, reproducing a test case required separately retrieving the original user properties file, the correct database configuration file, the CLI arguments used, and the decisions taken at runtime. If even one piece was missing, reproduction became a matter of trial and error.\n\nWith TAF 4.0, each run produces a single file that contains, in the order in which TAF applies them:\n\n1. DB_CONFIG_USED: the database configuration that won out among the three possible sources (a file passed via CLI with --db-config-file=..., an inline [db_config] block within the properties file, or an external file referenced within the file itself).\n2. The original user properties file, but in its fully resolved version: includes expansions, applied defaults, resolved environment values, and merged workload parameters.\n3. The significant CLI overrides — only those that actually changed the final configuration — converted into properties and appended at the end of the file, so they take precedence over the values above (property resolution works top to bottom).\n\nThe resulting file is saved in the results archive and allows the exact same test to be re-run with:\n\n\ntaf --prop=generated_user_properties.properties\n\n\nAccording to the Foundation, this makes test cases "portable, deterministic and future-proof" across different machines, environments and versions.\n\n## What's coming next\n\nThe next blog post will cover the integration of PostgreSQL into TAF as a first-class database, covering installation and cluster management, the PostgreSQL database plugin, mid-tier SQL support, and integration with test suites such as HammerDB TPCC.\n\nThe Foundation also notes that development and validation of TAF 4.0 took place on hosts provided by Hetzner: a machine with an Intel i5-13500 (20 vCPUs/14 cores, 62 GB RAM, AlmaLinux 9.7) and one with an AMD EPYC 9454 (96 vCPUs/48 cores, 125 GB RAM, AlmaLinux 9.8).\n\nTAF is released openly, and the Foundation encourages database vendors to adopt it for their own performance testing.