ccache parser and Prometheus exporter

A Prometheus exporter for the ccache compiler cache statistics, and its companion Go parser.

Metrics exposed

Counters (internal):

• ccache_collector_parsing_errors_total

Counters (ccache):

• ccache_call_total
• ccache_call_hit_total
• ccache_called_for_link_total
• ccache_called_for_preprocessing_total
• ccache_cleanups_performed_total
• ccache_compilation_failed_total
• ccache_no_input_file_total
• ccache_preprocessing_failed_total
• ccache_remote_storage_errors_total
• ccache_remote_storage_hit_total
• ccache_remote_storage_miss_total
• ccache_remote_storage_read_hit_total
• ccache_remote_storage_read_miss_total
• ccache_remote_storage_timeout_total
• ccache_remote_storage_write_total
• ccache_unsupported_code_directive_total

Gauges (ccache):

• ccache_cache_hit_ratio
• ccache_cache_size_bytes
• ccache_cache_size_max_bytes
• ccache_cached_files

Building

Get the sources:

$ git clone https://github.com/virtualtam/ccache_exporter.git
$ cd ccache_exporter

Run linters:

$ make lint

Build the parser and exporter:

$ make build

Build platform-specific binaries with Promu:

$ promu crossbuild

Build and archive platform-specific binaries:

$ promu crossbuild
$ promu crossbuild tarballs

Parser usage

For ccache 3.7 and above:

$ ccache --print-stats | ccacheparser | jq

{
  "stats_time": "2022-07-31T20:39:33Z",
  "stats_zero_time": "2022-07-29T17:04:53Z",
  "cache_hit_direct": 192,
  "cache_hit_preprocessed": 2,
  "cache_miss": 535,
  "cache_miss_direct": 276,
  "cache_miss_preprocessed": 259,
  "cache_hit_rate": 26.611796982167352,
  "cache_hit_ratio": 0.2661179698216735,
  "called_for_link": 132,
  "called_for_preprocessing": 0,
  "unsupported_code_directive": 0,
  "no_input_file": 13,
  "cleanups_performed": 0,
  "files_in_cache": 508,
  "cache_size": "8MB",
  "cache_size_bytes": 8159232
}

Running the demo with Docker Compose

The provided docker-compose.yml script defines the following monitoring stack:

• ccache-exporter service bind-mounted on the user's $HOME directory;
• node-exporter service to gather system metrics;
• prometheus database, preconfigured to scrap exported ccache metrics;
• grafana dashboard, preconfigured to use prometheus as a data source and display ccache metrics in the corresponding dashboard.

To pull Docker images and start the services:

$ docker-compose pull
$ docker-compose up -d

Once the stack is up, the following services will be exposed:

• http://localhost:19508: ccache-exporter
• http://localhost:19100: node-exporter
• http://localhost:19090: prometheus
• http://localhost:13000: grafana

Then, login to Grafana with the default credentials (admin/admin) and load the ccache dashboard:

Change Log

See CHANGELOG

License

ccache_exporter is licenced under the MIT License.