mariadb_exporter

MariaDB metrics exporter for Prometheus written in Rust.

Goals

mariadb_exporter focuses on DBRE-friendly, selective metrics:

• Modular collectors – Enable only what you need; heavy/optional plugins stay off by default.
• Compatibility – Metric names align with Prometheus mysqld_exporter (prefixed mariadb_).
• Lean defaults – Useful availability/innodb/replication basics on by default; optional collectors gated.
• Low footprint – Avoid unnecessary cardinality and expensive scans.

Download or build

Install via Cargo:

cargo install mariadb_exporter

Usage

Run the exporter:

mariadb_exporter --dsn "mysql://user:password@localhost:3306/mysql"

Change port (default 9306):

mariadb_exporter --dsn "mysql://user:password@localhost:3306/mysql" --port 9187

Common DSN formats:

• TCP: mysql://user:password@host:3306/database
• Unix socket: mysql:///mysql?socket=/var/run/mysqld/mysqld.sock&user=exporter
• TLS required: mysql://user@host/mysql?ssl-mode=REQUIRED
• TLS verify identity: mysql://user@host/mysql?ssl-mode=VERIFY_IDENTITY&ssl-ca=/path/to/ca.pem

Available collectors

Collectors are toggled with --collector.<name> or --no-collector.<name>.

• --collector.default (enabled) – Core status (uptime, threads, connections, traffic), InnoDB basics, replication basics, binlog stats, config flags, version, mariadb_up.
• --collector.exporter (enabled) – Exporter self-metrics (process, scrape, cardinality).
• --collector.tls – TLS session + cipher info.
• --collector.query_response_time – Buckets from query_response_time plugin.
• --collector.audit – Audit plugin status.
• --collector.statements – Statement digest summaries/top latency from performance_schema.
• --collector.schema – Table size/row estimates (largest 20 non-system tables).
• --collector.replication – Relay log size/pos, binlog file count.
• --collector.locks – Metadata/table lock waits from performance_schema.
• --collector.metadata – metadata_lock_info table counts.
• --collector.userstat – Per-user stats (requires @@userstat=1 and USER_STATISTICS).

Enabled by default

• default
• exporter

Everything else is opt-in.

Project layout

mariadb_exporter
├── bin
├── cli
├── collectors
│   ├── audit
│   ├── config.rs
│   ├── default
│   ├── exporter
│   ├── locks
│   ├── metadata
│   ├── mod.rs
│   ├── query_response_time
│   ├── register_macro.rs
│   ├── registry.rs
│   ├── replication
│   ├── schema
│   ├── statements
│   ├── tls
│   ├── userstat
│   └── util.rs
└── src/lib.rs

Each collector lives in its own subdirectory for clarity and easy extension.

Testing

Run tests:

cargo test

Run with container-backed integration (requires podman/docker):

just test

Lint:

cargo clippy --all-targets --all-features

Notes

• User statistics: enable with SET GLOBAL userstat=ON; (or @@userstat=1) to expose userstat metrics.
• Metadata locks: load metadata_lock_info plugin for the metadata collector.
• Performance schema is needed for statements/locks collectors to return data.
• Optional collectors skip gracefully when prerequisites aren’t present.***