status-go/metrics

Description

This package configures Prometheus metrics for the node.

Technical Details

We use a trick to combine our metrics with Geth ones.

The NewMetricsServer() function in metrics.go calls our own Handler() function which in turn calls two handlers:

• promhttp.HandlerFor() - Our own custom metrics from this package.
• gethprom.Handler(reg) - Geth metrics defined in metrics

By calling both we can extend existing metrics.

Metrics

We add a few extra metrics on top of the normal Geth ones in node/metrics.go:

• p2p_peers_count - Current numbers of peers split by name.
• p2p_peers_absolute - Absolute number of connected peers.
• p2p_peers_max - Maximum number of peers that can connect.

The p2p_peers_count metrics includes 3 labels:

• type - Set to StatusIM for mobile and Statusd for daemon.
• version - Version of status-go, always with the v prefix.
• platform - Host platform, like android-arm64 or darwin-arm64

The way this data is acquired is using node names, which look like this:

StatusIM/vrelease-0.30.1-beta.2/android-arm/go1.11.5
Statusd/v0.34.0-beta.3/linux-amd64/go1.13.1
Geth/v1.9.9-stable-5aa131ca/linux-amd64/go1.13.3

This 4 segment format is standard for Ethereum as you can see on https://ethstats.net/.

We parse the names using labelsFromNodeName() from node/metrics.go.

Links

• https://github.com/status-im/infra-misc/issues/26
• https://github.com/status-im/status-go/pull/1648