Installing the observability stack

WEM requires Prometheus and Loki to enable monitoring and log aggregation features. Alertmanager is required to enable the alerts integration. You can deploy dedicated instances for WEM or integrate with an existing enterprise monitoring stack.

For a reference deployment using Docker Compose, see the warehouse-pg-observability-demo repository, which provides a working example with Prometheus, Loki, and Alertmanager pre-configured for WEM.

Note

Once WEM is installed, an example prometheus.yml and pre-built alert rule files (wem-*.rules.yml) are available at /usr/local/greenplum-db/wem/config/prometheus/ on the WEM host. Use these as a starting point when configuring your Prometheus instance.

Installing Prometheus

Prometheus collects and stores the metrics that WEM uses to display cluster performance data.

Download and install Prometheus from the official releases page, or install it using your system package manager.
Configure a prometheus.yml to enable the remote write receiver, which the WEM Collector uses to push metrics. The example file at /usr/local/greenplum-db/wem/config/prometheus/prometheus.yml on the WEM host provides a ready-to-use starting point. At minimum, add the following:
```
global:
  scrape_interval: 15s

# Enable remote write receiver so the WEM Collector can push metrics
```
Start Prometheus with --web.enable-remote-write-receiver to accept inbound metrics:
```
./prometheus --config.file=prometheus.yml --web.enable-remote-write-receiver
```
Load the WEM alert rules. Once WEM is installed, copy the pre-built rule files to the path referenced in your prometheus.yml under rule_files:
```
cp /usr/local/greenplum-db/wem/config/prometheus/alerts/*.rules.yml /etc/wem/prometheus/alerts/
```
The example prometheus.yml included with WEM already references this path. See Alert rules for a description of each rule.

Verify Prometheus is running:

curl http://<prometheus-host>:9090/-/healthy

Installing Loki

Loki receives and stores WarehousePG log data forwarded by the WEM Collector.

Download and install Loki from the official releases page, or install it using your system package manager.
Start Loki with a minimal configuration:
```
./loki -config.file=loki-local-config.yaml
```
Verify Loki is accepting log pushes:
```
curl http://<loki-host>:3100/ready
```

Installing Alertmanager

Alertmanager is required to enable WEM's alert routing and notification features. Without it, the Alerts panel in WEM is not available.

Download and install Alertmanager from the official releases page, or install it using your system package manager.

Create an alertmanager.yml with your notification routing. For example, to route all alerts to a Slack channel:

global:
  slack_api_url: 'https://hooks.slack.com/services/YOUR/SLACK/WEBHOOK'

route:
  receiver: 'slack-notifications'

receivers:
  - name: 'slack-notifications'
    slack_configs:
      - channel: '#alerts'
        text: '{{ .CommonAnnotations.summary }}'

Start Alertmanager:

./alertmanager --config.file=alertmanager.yml

Verify Alertmanager is running:

curl http://<alertmanager-host>:9093/-/healthy