Add tracing support to node (#1940)

* drop in tracing to replace log

* add structured logging to trace messages

* add structured logging to debug messages

* add structured logging to info messages

* add structured logging to warn messages

* add structured logging to error messages

* normalize spacing and Display vs Debug

* add instrumentation to the various 'fn run'

* use explicit tracing module throughout

* fix availability distribution test

* don't double-print errors

* remove further redundancy from logs

* fix test errors

* fix more test errors

* remove unused kv_log_macro

* fix unused variable

* add tracing spans to collation generation

* add tracing spans to av-store

* add tracing spans to backing

* add tracing spans to bitfield-signing

* add tracing spans to candidate-selection

* add tracing spans to candidate-validation

* add tracing spans to chain-api

* add tracing spans to provisioner

* add tracing spans to runtime-api

* add tracing spans to availability-distribution

* add tracing spans to bitfield-distribution

* add tracing spans to network-bridge

* add tracing spans to collator-protocol

* add tracing spans to pov-distribution

* add tracing spans to statement-distribution

* add tracing spans to overseer

* cleanup

polkadot/node/subsystem/Cargo.toml

@@ -10,7 +10,8 @@ async-trait = "0.1.41"
 derive_more = "0.99.11"
 futures = "0.3.8"
 futures-timer = "3.0.2"
-log = "0.4.11"
+tracing = "0.1.21"
+tracing-futures = "0.2.4"
 parity-scale-codec = { version = "1.3.5", default-features = false, features = ["derive"] }
 parking_lot = { version = "0.11.1", optional = true }
 pin-project = "1.0.2"

polkadot/node/subsystem/src/lib.rs

@@ -239,7 +239,7 @@ where
 					Err(_) => return Ok(()),
 					Ok(FromOverseer::Signal(OverseerSignal::Conclude)) => return Ok(()),
 					Ok(overseer_msg) => {
-						log::debug!(
+						tracing::debug!(
 							target: "dummy-subsystem",
 							"Discarding a message sent from overseer {:?}",
 							overseer_msg