Prometheus is a well known and widely used monitoring and time-series database, often used in combination with Grafana.
cachegrand provides a module to expose metrics for Prometheus via an HTTP endpoint that can be configured using the config file.
To enable the module is enough to add the module configuration to the modules section in the config file:
- type: prometheus
timeout:
read_ms: 10000
write_ms: 10000
bindings:
- host: 127.0.0.1
port: 9090The module currently doesn't provide any sort of authentication or https support.
The metrics are exposed on the /metrics endpoint.
The available metrics are:
| Name | Description | Type |
|---|---|---|
| cachegrand_network_total_received_packets | Total amount of received packets | Counter |
| cachegrand_network_total_received_data | Total amount of received data (in bytes) | Counter |
| cachegrand_network_total_sent_packets | Total amount of sent packets | Counter |
| cachegrand_network_total_sent_data | Total amount of sent data | Counter |
| cachegrand_network_total_accepted_connections | Total amount of accepted connections | Counter |
| cachegrand_network_total_active_connections | Total amount of active connections | Counter |
| cachegrand_storage_total_written_data | Total amount of data written to disk | Counter |
| cachegrand_storage_total_write_iops | Total amount of write IOPS | Counter |
| cachegrand_storage_total_read_data | Total amount of read data from disk | Counter |
| cachegrand_storage_total_read_iops | Total amount of read IOPS | Counter |
| cachegrand_storage_total_open_files | Total amount of open files | Counter |
| cachegrand_uptime | Uptime in seconds | Counter |
It is possible to tag the metrics with any amount of arbitrary labels using environment variables.
If one or more environment variables prefixed with CACHEGRAND_METRIC_ENV_ exist then these will be parsed by
cachegrand and the suffix will be converted to lowercase and used as name of the label and the value of the environment
variable will be used as value.