refactor: drop unused cadence metrics (#243)

Cargo.lock

@@ -470,15 +470,6 @@ dependencies = [
  "bytes",
 ]
 
-[[package]]
-name = "cadence"
-version = "1.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62fd689c825a93386a2ac05a46f88342c6df9ec3e79416f665650614e92e7475"
-dependencies = [
- "crossbeam-channel",
-]
-
 [[package]]
 name = "camino"
 version = "1.1.9"
@@ -3575,7 +3566,6 @@ dependencies = [
  "actix-web-lab",
  "anyhow",
  "badge",
- "cadence",
  "crates-index",
  "derive_more 1.0.0",
  "dotenvy",

Cargo.toml

@@ -17,7 +17,6 @@ badge = { path = "./libs/badge" }
 actix-web = "4"
 actix-web-lab = "0.23"
 anyhow = "1"
-cadence = "1"
 crates-index = { version = "3", default-features = false, features = ["git"] }
 derive_more = { version = "1", features = ["display", "error", "from"] }
 dotenvy = "0.15"

src/engine/mod.rs

@@ -1,13 +1,11 @@
 use std::{
     collections::HashSet,
-    panic::RefUnwindSafe,
     sync::{Arc, LazyLock},
     time::{Duration, Instant},
 };
 
 use actix_web::dev::Service;
 use anyhow::{anyhow, Error};
-use cadence::{MetricSink, NopMetricSink, StatsdClient};
 use futures_util::{
     future::try_join_all,
     stream::{self, LocalBoxStream},
@@ -39,7 +37,6 @@ use self::fut::{analyze_dependencies, crawl_manifest};
 
 #[derive(Debug, Clone)]
 pub struct Engine {
-    metrics: Arc<StatsdClient>,
     query_crate: Cache<QueryCrate, CrateName>,
     get_popular_crates: Cache<GetPopularCrates, ()>,
     get_popular_repos: Cache<GetPopularRepos, ()>,
@@ -49,8 +46,6 @@ pub struct Engine {
 
 impl Engine {
     pub fn new(client: reqwest::Client, index: ManagedIndex) -> Engine {
-        let metrics = Arc::new(StatsdClient::from_sink("engine", NopMetricSink));
-
         let query_crate = Cache::new(QueryCrate::new(index), Duration::from_secs(10), 500);
         let get_popular_crates = Cache::new(
             GetPopularCrates::new(client.clone()),
@@ -70,7 +65,6 @@ impl Engine {
         );
 
         Engine {
-            metrics,
             query_crate,
             get_popular_crates,
             get_popular_repos,
@@ -78,10 +72,6 @@ impl Engine {
             fetch_advisory_db,
         }
     }
-
-    pub fn set_metrics<M: MetricSink + Send + Sync + RefUnwindSafe + 'static>(&mut self, sink: M) {
-        self.metrics = Arc::new(StatsdClient::from_sink("engine", sink));
-    }
 }
 
 #[derive(Debug)]

src/main.rs

@@ -1,18 +1,13 @@
 #![deny(rust_2018_idioms)]
 #![warn(missing_debug_implementations)]
 
-use std::{
+use std::{env, net::Ipv4Addr, time::Duration};
-    env,
-    net::{Ipv4Addr, UdpSocket},
-    time::Duration,
-};
 
 use actix_web::{
     middleware::Logger,
     web::{self, ThinData},
 };
 use actix_web_lab::middleware::NormalizePath;
-use cadence::{QueuingMetricSink, UdpMetricSink};
 use reqwest::redirect::Policy as RedirectPolicy;
 
 mod engine;
@@ -26,14 +21,6 @@ use self::{engine::Engine, utils::index::ManagedIndex};
 
 const DEPS_RS_UA: &str = "deps.rs";
 
-fn init_metrics() -> QueuingMetricSink {
-    let socket = UdpSocket::bind("0.0.0.0:0").unwrap();
-    socket.set_nonblocking(true).unwrap();
-    let host = ("127.0.0.1", 8125);
-    let sink = UdpMetricSink::from(host, socket).unwrap();
-    QueuingMetricSink::from(sink)
-}
-
 fn init_tracing_subscriber() {
     use tracing::level_filters::LevelFilter;
     use tracing_subscriber::{fmt, prelude::*, EnvFilter};
@@ -57,7 +44,6 @@ fn init_tracing_subscriber() {
 async fn main() {
     dotenvy::dotenv().ok();
     init_tracing_subscriber();
-    let metrics = init_metrics();
 
     let client = reqwest::Client::builder()
         .user_agent(DEPS_RS_UA)
@@ -81,8 +67,7 @@ async fn main() {
         });
     }
 
-    let mut engine = Engine::new(client.clone(), index);
+    let engine = Engine::new(client.clone(), index);
-    engine.set_metrics(metrics);
 
     let server = actix_web::HttpServer::new(move || {
         actix_web::App::new()