| # Build API Metrics |
| |
| [TOC] |
| |
| ## Overview |
| |
| The overarching intent of the Build API Metrics subsystem is to enable |
| exploration, and eventually monitoring and alerting for build-related |
| performance issues. |
| |
| The Build API Metrics subsystem is defined in terms of Metric Events. |
| See `infra/proto/src/chromiumos/metrics.proto`. |
| |
| ## How it works |
| |
| During an invocation of the Build API, we set up an environment variable |
| `BUILD_API_METRICS_LOG` which specifies a log file into which metric events can |
| be appended. Afterwards, the Build API can call into the `utils/metrics.py` code |
| to read the metric events out (see `chromite.api.deserialize_metrics_log`.) This |
| data is transformed into MetricEvents (as per `metrics.proto`). These are fed |
| back through the Build API's Response message which is returned to the `recipes` |
| code. There it is uploaded into BigTable for later exploration using various |
| front-ends, such as Dremel. |
