0g-chain/x/metrics/spec/README.md
Robert Pirtle 9a0aed7626
feat(x/metrics): add module for emiting custom chain metrics (#1668)
* initialize x/metrics with metrics collection

* include global labels in x/metrics metrics

* add x/metrics spec

* add x/metrics test coverage

* update changelog
2023-08-25 12:23:53 -07:00

1.2 KiB

metrics

Abstract

x/metrics is a stateless module that does not affect consensus. It captures chain metrics and emits them when the instrumentation.prometheus option is enabled in config.toml.

Precision

The metrics emitted by x/metrics are float64s. They use github.com/go-kit/kit/metrics Prometheus gauges. Cosmos-sdk's telemetry package was not used because, at the time of writing, it only supports float32s and so does not maintain accurate representations of ints larger than ~16.8M. With float64s, integers may be accurately represented up to ~9e15.

Metrics

The following metrics are defined:

  • cometbft_blocksync_latest_block_height - this emulates the blocksync latest_block_height metric in CometBFT v0.38+. The cometbft namespace comes from the instrumentation.namespace config.toml value.

Metric Labels

All metrics emitted have the labels defined in app.toml's telemetry.global-labels field. This is the same field used by cosmos-sdk's telemetry package.

example:

# app.toml
[telemetry]
global-labels = [
  ["chain_id", "kava_2222-10"],
  ["my_label", "my_value"],
]