wal-g-exporter

wal-g-exporter is a Prometheus exporter for gathering WAL-G backup metrics for the PostgreSQL database.

Features and limitations

Primary/Secondary Node Discovery

wal-g-exporter is aware of whether it is running on a primary instance or not. It will not collect and export metrics for standby/follower instances and will become aware of a role change while running. This ensures that you can always collect metrics from all exporters in the PostgreSQL cluster with no unwanted accumulation of metrics between the exporters.

http/oneshot Modes

wal-g-exporter has two operating modes (EXPORTER_OPS_MODE environment variable):

• http - run an HTTP server on EXPORTER_HTTP_PORT to make metrics accessible, like most exporters. Default
• oneshot - write metrics to EXPORTER_METRICS_FILE. The service creates a metrics file and then shuts down. In Docker, you can use a volume to save the file on disk. It can then be taken by node-exporter to serve your exporter metrics.

Open this link to read more about the textfile collector.

Configuration

The following environment variables can be used to configure wal-g-exporter.

Variable Name	Default Value	Description
PGHOST	localhost	PostgreSQL host (set to '/var/run/postgresql/' to use unix socket)
PGPORT	5432	PostgreSQL port
PGUSER	postgres	PostgreSQL user
POSTGRES_DB	postgres	PostgreSQL database name
POSTGRES_PASSWORD		PostgreSQL password (no default, must be set in env)
PGSSLMODE	allow	PostgreSQL SSL mode
WAL_G_SCRAPE_INTERVAL	60	Interval for scraping WAL-G metrics (for 'http' mode).
EXPORTER_OPS_MODE	http	Operation mode for the exporter ('http' or 'oneshot').
EXPORTER_HTTP_PORT	9351	Port for HTTP service.
EXPORTER_UNIT_NAME	wal-g	Unit name for the exporter. Becomes a label on every metric.
EXPORTER_METRICS_FILE	/prometheus/wal-g.prom	Path to the metrics file for Node exporter textfile collector.

Metrics

Metric name	Labels	Description
walg_basebackup_count		Number of basebackups stored on S3
walg_oldest_basebackup		Timestamp of the oldest basebackup
walg_newest_basebackup		Timestamp of the newest basebackup
walg_last_basebackup_duration		Duration in seconds of the last basebackup
walg_last_basebackup_throughput_bytes		Throughput in bytes of the last basebackup
walg_wal_archive_count		Number of WAL archives stored on S3
walg_wal_archive_missing_count		Amount of missing WAL archives, will only be > 0 when walg_wal_integrity_status is FAILURE
walg_wal_integrity_status	OK, WARNING, FAILURE	Can be 1 or 0, while 1 means that the integrity_status is true
walg_last_upload	basebackup, wal	Timestamp of the last upload to S3 of the respective label / file type
walg_s3_diskusage		Disk usage on S3 in byte for all backup / archive objects related to this Postgres instance

Every metric receives a label unit that can help you identify your instance if you use multiple on the host at the same time.

The unit label takes it's data from the EXPORTER_UNIT_NAME environment variable!

Credits

• thedatabaseme - Fork source author
• camptocamp - Original project authors