Crate metrics_example

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§Description

The example showcases how to run a p2p network with libp2p and collect metrics using libp2p-metrics as well as span data via opentelemetry. It sets up multiple nodes in the network and measures various metrics, such as libp2p_ping, to evaluate the network’s performance.

§Usage

To run the example, follow these steps:

  1. Run the following command to start the first node:

    cargo run

  2. Open a second terminal and run the following command to start a second node:

    cargo run -- <listen-addr-of-first-node>

    Replace <listen-addr-of-first-node> with the listen address of the first node reported in the first terminal. Look for the line that says NewListenAddr to find the address.

  3. Open a third terminal and run the following command to retrieve the metrics from either the first or second node:

    curl localhost:<metrics-port-of-first-or-second-node>/metrics

    Replace <metrics-port-of-first-or-second-node> with the listen port of the metrics server of either the first or second node. Look for the line that says tide::server Server listening on to find the port.

    After executing the command, you should see a long list of metrics printed to the terminal. Make sure to check the libp2p_ping metrics, which should have a value greater than zero (>0).

§Opentelemetry

To see the span data collected as part of the Swarms activity, start up an opentelemetry collector:

docker compose up

Then, configure tracing to output spans:

export RUST_LOG=info,[ConnectionHandler::poll]=trace,[NetworkBehaviour::poll]=trace

Next, (re)-start the two example for it to connect to the OTEL collector. Finally, open the Jaeger UI in a browser and explore the spans: http://localhost:16686.

§Filtering spans

For a precise documentation, please see the following documentation in tracing: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#directives.

rust-libp2p consistently applies spans to the following functions:

  • ConnectionHandler::poll implementations
  • NetworkBehaviour::poll implementations

The above spans are all called exactly that: ConnectionHandler::poll and NetworkBehaviour::poll. You can activate all of them by setting:

RUST_LOG=[ConnectionHandler::poll]=trace

If you just wanted to see the spans of the libp2p_ping crate, you can filter like this:

RUST_LOG=libp2p_ping[ConnectionHandler::poll]=trace

§Conclusion

This example demonstrates how to utilize the libp2p-metrics crate to collect and analyze metrics in a libp2p network. By running multiple nodes and examining the metrics, users can gain insights into the network’s performance and behavior.

Modules§

http_service 🔒

Structs§

Behaviour 🔒
Our network behaviour.

Enums§

BehaviourEvent 🔒
NetworkBehaviour::ToSwarm produced by Behaviour.

Functions§

main 🔒
setup_tracing 🔒