Multi-target support is currently in BETA and may require changes in future releases. Feedback is welcome.
The PostgreSQL Server Exporter supports the multi-target pattern , allowing you to monitor multiple PostgreSQL instances from a single exporter instance.
When to Use Multi-target Multi-target functionality is optional and intended for specific use cases:
Monitoring SaaS-managed PostgreSQL services where you cannot install the exporter as a sidecar
Centralized monitoring of many PostgreSQL instances
Dynamic PostgreSQL targets that change frequently
For most deployments, running the exporter as a sidecar (one per PostgreSQL instance) is simpler and recommended.
How It Works Instead of configuring a single data source via environment variables, the exporter exposes a /probe endpoint that accepts target information as URL parameters.
Basic Usage Send HTTP requests to the /probe endpoint with the target DSN:
curl "http://localhost:9187/probe?target=postgres-server1:5432"
The target parameter should contain the DSN (Data Source Name) of the PostgreSQL instance to scrape.
Authentication Modules To avoid putting sensitive credentials in URLs, configure authentication modules in the exporter’s configuration file.
Configuration File Create a postgres_exporter.yml file with auth module definitions:
auth_modules : production : type : userpass userpass : username : postgres_exporter password : your_secure_password options : sslmode : require connect_timeout : "10" development : type : userpass userpass : username : dev_monitor password : dev_password options : sslmode : disable
Using Auth Modules Reference the auth module in the probe request:
curl "http://localhost:9187/probe?target=server1:5432&auth_module=production"
The exporter will:
Look up the production auth module
Apply the username and password
Add any configured options to the DSN
Connect to server1:5432 and collect metrics
Prometheus Configuration Configure Prometheus to scrape multiple targets through the exporter using relabeling:
scrape_configs : - job_name : 'postgres' static_configs : - targets : - server1:5432 - server2:5432 - server3:5432 metrics_path : /probe params : auth_module : [ production ] relabel_configs : # Pass the target as a URL parameter - source_labels : [ __address__ ] target_label : __param_target # Use the target as the instance label - source_labels : [ __param_target ] target_label : instance # Replace the scrape address with the exporter's address - target_label : __address__ replacement : localhost:9187
How Relabeling Works
First relabel : Takes the target address (e.g., server1:5432) and sets it as the target URL parameterSecond relabel : Copies the target to the instance label so metrics show the correct PostgreSQL instanceThird relabel : Changes the scrape address to the exporter’s actual location
Multiple Environments You can scrape different PostgreSQL environments with different auth modules:
scrape_configs : - job_name : 'postgres-prod' static_configs : - targets : - prod-db1:5432 - prod-db2:5432 metrics_path : /probe params : auth_module : [ production ] relabel_configs : - source_labels : [ __address__ ] target_label : __param_target - source_labels : [ __param_target ] target_label : instance - target_label : __address__ replacement : localhost:9187 - job_name : 'postgres-dev' static_configs : - targets : - dev-db1:5432 metrics_path : /probe params : auth_module : [ development ] relabel_configs : - source_labels : [ __address__ ] target_label : __param_target - source_labels : [ __param_target ] target_label : instance - target_label : __address__ replacement : localhost:9187
Starting the Exporter Start the exporter with the configuration file:
./postgres_exporter --config.file=postgres_exporter.yml
Or with Docker:
docker run -p 9187:9187 \ -v $( pwd ) /postgres_exporter.yml:/etc/postgres_exporter.yml \ quay.io/prometheuscommunity/postgres-exporter \ --config.file=/etc/postgres_exporter.yml
Limitations
Currently, only userpass authentication type is supported
Each scrape creates a new connection to the target database
Connection pooling is not available in multi-target mode
See the Performance Tuning guide for optimization tips
Next Steps
Security Best Practices Learn how to secure your exporter deployment
Performance Tuning Optimize collection timeouts and collector selection