Reduce tracing spans to the debug level (#730)

We currently set almost all span metadata at the info level, meaning
that these spans are recorded/maintained for all connections/requests
even though there are virtually no logs emitted with this metadata at
the info level.

This changes all of these spans to only be recorded at the debug level.
Exceptions to this include the per-connection `accept` span and the
top-level "inbound"|"outbound"|etc spans.

Author: olix0r

linkerd/app/gateway/src/config.rs

@@ -4,7 +4,7 @@ use linkerd2_app_core::{
 };
 use linkerd2_app_inbound::endpoint as inbound;
 use linkerd2_app_outbound as outbound;
-use tracing::info_span;
+use tracing::debug_span;
 
 #[derive(Clone, Debug, Default)]
 pub struct Config {
@@ -51,7 +51,7 @@ impl Config {
                 Allow(self.allow_discovery),
             ))
             .check_new_service::<inbound::Target, http::Request<http::boxed::Payload>>()
-            .instrument(|_: &inbound::Target| info_span!("gateway"))
+            .instrument(|_: &inbound::Target| debug_span!("gateway"))
             .into_inner()
     }
 }

linkerd/app/inbound/src/endpoint.rs

@@ -273,16 +273,16 @@ impl tap::Inspect for Target {
 
 impl stack_tracing::GetSpan<()> for Target {
     fn get_span(&self, _: &()) -> tracing::Span {
-        use tracing::info_span;
+        use tracing::debug_span;
 
         match self.http_version {
             http::Version::H2 => match self.dst.name_addr() {
-                None => info_span!("http2"),
-                Some(name) => info_span!("http2", %name),
+                None => debug_span!("http2"),
+                Some(name) => debug_span!("http2", %name),
             },
             http::Version::Http1 => match self.dst.name_addr() {
-                None => info_span!("http1"),
-                Some(name) => info_span!("http1", %name),
+                None => debug_span!("http1"),
+                Some(name) => debug_span!("http1", %name),
             },
         }
     }

linkerd/app/inbound/src/lib.rs

@@ -30,7 +30,7 @@ use linkerd2_app_core::{
 };
 use std::{collections::HashMap, time::Duration};
 use tokio::{net::TcpStream, sync::mpsc};
-use tracing::{debug_span, info_span};
+use tracing::debug_span;
 
 mod allow_discovery;
 pub mod endpoint;
@@ -105,7 +105,7 @@ impl Config {
         let tcp_forward = svc::stack(tcp_connect)
             .push_make_thunk()
             .push_on_response(svc::layer::mk(tcp::Forward::new))
-            .instrument(|_: &_| info_span!("tcp"))
+            .instrument(|_: &_| debug_span!("tcp"))
             .into_inner();
 
         let accept = self.build_accept(
@@ -369,7 +369,7 @@ impl Config {
             )
             .push(svc::layer::mk(http::normalize_uri::MakeNormalizeUri::new))
             .push_map_target(|(_, accept): (_, TcpAccept)| accept)
-            .instrument(|(v, _): &(http::Version, _)| info_span!("http", %v))
+            .instrument(|(v, _): &(http::Version, _)| debug_span!("http", %v))
             .check_new_service::<(http::Version, TcpAccept), http::Request<_>>()
             .into_inner();
 

linkerd/app/outbound/src/http/endpoint.rs

@@ -12,7 +12,7 @@ use linkerd2_app_core::{
     svc, Error, TraceContext, CANONICAL_DST_HEADER, L5D_REQUIRE_ID,
 };
 use tokio::{io, sync::mpsc};
-use tracing::info_span;
+use tracing::debug_span;
 
 pub fn stack<B, C>(
     config: &ConnectConfig,
@@ -69,6 +69,6 @@ where
         ]))
         .push_on_response(svc::layers().box_http_response())
         .check_new::<Endpoint>()
-        .instrument(|e: &Endpoint| info_span!("endpoint", peer.addr = %e.addr))
+        .instrument(|e: &Endpoint| debug_span!("endpoint", peer.addr = %e.addr))
         .into_inner()
 }

linkerd/app/outbound/src/http/logical.rs

@@ -7,7 +7,7 @@ use linkerd2_app_core::{
     proxy::{api_resolve::Metadata, core::Resolve, http},
     retry, svc, Addr, Error, CANONICAL_DST_HEADER, DST_OVERRIDE_HEADER,
 };
-use tracing::info_span;
+use tracing::debug_span;
 
 pub fn stack<B, E, S, R>(
     config: &ProxyConfig,
@@ -74,8 +74,8 @@ where
         .into_new_service()
         .check_new_service::<Concrete, http::Request<_>>()
         .instrument(|c: &Concrete| match c.resolve.as_ref() {
-            None => info_span!("concrete"),
-            Some(addr) => info_span!("concrete", %addr),
+            None => debug_span!("concrete"),
+            Some(addr) => debug_span!("concrete", %addr),
         })
         .check_new_service::<Concrete, http::Request<_>>()
         // The concrete address is only set when the profile could be
@@ -116,7 +116,7 @@ where
                 .push(http::strip_header::request::layer(DST_OVERRIDE_HEADER))
                 .push(svc::layers().box_http_response()),
         )
-        .instrument(|l: &Logical| info_span!("logical", dst = %l.addr()))
+        .instrument(|l: &Logical| debug_span!("logical", dst = %l.addr()))
         .check_new_service::<Logical, http::Request<_>>()
         .into_inner()
 }

linkerd/app/outbound/src/ingress.rs

@@ -10,7 +10,7 @@ use linkerd2_app_core::{
     Addr, AddrMatch, Error, TraceContext,
 };
 use tokio::sync::mpsc;
-use tracing::info_span;
+use tracing::{debug_span, info_span};
 
 /// Routes HTTP requests according to the l5d-dst-override header.
 ///
@@ -93,6 +93,7 @@ where
         .spawn_buffer(buffer_capacity)
         .into_new_service()
         .check_new_service::<Target, http::Request<_>>()
+        .instrument(|t: &Target| info_span!("target", dst = %t.dst))
         .push(svc::layer::mk(|inner| {
             svc::stack::NewRouter::new(TargetPerRequest::accept, inner)
         }))
@@ -120,7 +121,7 @@ where
         .check_new_service::<http::Accept, http::Request<_>>()
         .push(svc::layer::mk(http::normalize_uri::MakeNormalizeUri::new))
         .check_new_service::<http::Accept, http::Request<_>>()
-        .instrument(|a: &http::Accept| info_span!("http", v = %a.protocol))
+        .instrument(|a: &http::Accept| debug_span!("http", v = %a.protocol))
         .push_map_target(http::Accept::from)
         .check_new_service::<(http::Version, tcp::Accept), http::Request<_>>()
         .into_inner();

linkerd/app/outbound/src/server.rs

@@ -12,7 +12,7 @@ use linkerd2_app_core::{
 };
 use std::net::SocketAddr;
 use tokio::sync::mpsc;
-use tracing::info_span;
+use tracing::debug_span;
 
 pub fn stack<R, P, C, H, S, I>(
     config: &Config,
@@ -88,7 +88,7 @@ where
         )
         .check_new_service::<http::Logical, http::Request<_>>()
         .push(svc::layer::mk(http::normalize_uri::MakeNormalizeUri::new))
-        .instrument(|l: &http::Logical| info_span!("http", v = %l.protocol))
+        .instrument(|l: &http::Logical| debug_span!("http", v = %l.protocol))
         .push_map_target(http::Logical::from)
         .check_new_service::<(http::Version, tcp::Logical), http::Request<_>>()
         .into_inner();
@@ -106,7 +106,7 @@ where
             .push_failfast(dispatch_timeout)
             .push_spawn_buffer_with_idle_timeout(buffer_capacity, cache_max_idle_age),
     )
-    .instrument(|_: &_| info_span!("tcp"))
+    .instrument(|_: &_| debug_span!("tcp"))
     .check_new_service::<tcp::Logical, transport::io::PrefixedIo<transport::metrics::SensorIo<I>>>()
     .into_inner();
 

linkerd/app/outbound/src/tcp/balance.rs

@@ -7,7 +7,7 @@ use linkerd2_app_core::{
     transport::io,
     Addr, Error,
 };
-use tracing::info_span;
+use tracing::debug_span;
 
 /// Constructs a TCP load balancer.
 pub fn stack<C, R, I>(
@@ -41,7 +41,7 @@ where
         .push_make_thunk()
         .check_make_service::<Endpoint, ()>()
         .instrument(
-            |t: &Endpoint| info_span!("endpoint", peer.addr = %t.addr, peer.id = ?t.identity),
+            |t: &Endpoint| debug_span!("endpoint", peer.addr = %t.addr, peer.id = ?t.identity),
         )
         .check_make_service::<Endpoint, ()>()
         .push(resolve::layer(resolve, config.cache_max_idle_age * 2))

linkerd/proxy/http/src/h2.rs

@@ -13,7 +13,7 @@ use std::{
     task::{Context, Poll},
 };
 use tokio::io::{AsyncRead, AsyncWrite};
-use tracing::{debug, info_span, trace_span};
+use tracing::{debug, debug_span, trace_span};
 use tracing_futures::Instrument;
 
 #[derive(Copy, Clone, Debug, Default)]
@@ -107,7 +107,7 @@ where
 
                 Ok(Connection { tx })
             }
-            .instrument(info_span!("h2")),
+            .instrument(debug_span!("h2")),
         )
     }
 }

linkerd/service-profiles/src/client.rs

@@ -23,7 +23,7 @@ use tonic::{
     client::GrpcService,
 };
 use tower::retry::budget::Budget;
-use tracing::{debug, error, info_span, trace, warn};
+use tracing::{debug, debug_span, error, trace, warn};
 use tracing_futures::Instrument;
 
 #[derive(Clone, Debug)]
@@ -256,7 +256,7 @@ where
         mut self: Pin<&mut Self>,
         cx: &mut Context<'_>,
     ) -> Poll<Result<Profile, Error>> {
-        let span = info_span!("poll_profile");
+        let span = debug_span!("poll_profile");
         let _enter = span.enter();
 
         loop {