more resilient subsystems (#1908)

* backing: extract log target

* bitfield-signing: extract log target

* utils: fix a typo

* provisioner: extract log target

* candidate selection: remove unused error variant

* bitfield-distribution: change the return type of run

* pov-distribution: extract log target

* collator-protocol: simplify runtime request

* collation-generation: do not exit early on error

* collation-generation: do not exit on double init

* collator-protocol: do not exit on errors and rename LOG_TARGET

* collator-protocol: a workaround for ununused imports warning

* Update node/network/bitfield-distribution/src/lib.rs

* collation-generation: elevate warn! to error!

* collator-protocol: fix imports

* post merge fix

* fix compilation

polkadot/node/core/backing/src/lib.rs

@@ -68,6 +68,8 @@ use statement_table::{
 };
 use thiserror::Error;
 
+const LOG_TARGET: &str = "candidate_backing";
+
 #[derive(Debug, Error)]
 enum Error {
 	#[error("Candidate is not found")]
@@ -763,7 +765,7 @@ impl util::JobTrait for CandidateBackingJob {
 						Ok(x) => x,
 						Err(e) => {
 							log::warn!(
-								target: "candidate_backing",
+								target: LOG_TARGET,
 								"Failed to fetch runtime API data for job: {:?}",
 								e,
 							);
@@ -803,7 +805,7 @@ impl util::JobTrait for CandidateBackingJob {
 				Err(util::Error::NotAValidator) => { return Ok(()) },
 				Err(e) => {
 					log::warn!(
-						target: "candidate_backing",
+						target: LOG_TARGET,
 						"Cannot participate in candidate backing: {:?}",
 						e
 					);

polkadot/node/core/bitfield-signing/src/lib.rs

@@ -40,6 +40,7 @@ use thiserror::Error;
 
 /// Delay between starting a bitfield signing job and its attempting to create a bitfield.
 const JOB_DELAY: Duration = Duration::from_millis(1500);
+const LOG_TARGET: &str = "bitfield_signing";
 
 /// Each `BitfieldSigningJob` prepares a signed bitfield for a single relay parent.
 pub struct BitfieldSigningJob;
@@ -163,7 +164,7 @@ async fn get_core_availability(
 			Ok(None) => return Ok(false),
 			Err(e) => {
 				// Don't take down the node on runtime API errors.
-				log::warn!(target: "bitfield_signing", "Encountered a runtime API error: {:?}", e);
+				log::warn!(target: LOG_TARGET, "Encountered a runtime API error: {:?}", e);
 				return Ok(false);
 			}
 		};
@@ -288,7 +289,7 @@ impl JobTrait for BitfieldSigningJob {
 			{
 				Err(Error::Runtime(runtime_err)) => {
 					// Don't take down the node on runtime API errors.
-					log::warn!(target: "bitfield_signing", "Encountered a runtime API error: {:?}", runtime_err);
+					log::warn!(target: LOG_TARGET, "Encountered a runtime API error: {:?}", runtime_err);
 					return Ok(());
 				}
 				Err(err) => return Err(err),

polkadot/node/core/candidate-selection/src/lib.rs

@@ -24,8 +24,10 @@ use futures::{
 	prelude::*,
 };
 use polkadot_node_subsystem::{
-	errors::{ChainApiError, RuntimeApiError},
-	messages::{AllMessages, CandidateBackingMessage, CandidateSelectionMessage, CollatorProtocolMessage},
+	errors::ChainApiError,
+	messages::{
+		AllMessages, CandidateBackingMessage, CandidateSelectionMessage, CollatorProtocolMessage,
+	},
 };
 use polkadot_node_subsystem_util::{
 	self as util, delegated_subsystem, JobTrait, ToJobTrait,
@@ -118,8 +120,6 @@ enum Error {
 	OneshotRecv(#[from] oneshot::Canceled),
 	#[error(transparent)]
 	ChainApi(#[from] ChainApiError),
-	#[error(transparent)]
-	Runtime(#[from] RuntimeApiError),
 }
 
 impl JobTrait for CandidateSelectionJob {

polkadot/node/core/provisioner/src/lib.rs

@@ -45,6 +45,8 @@ use std::{convert::TryFrom, pin::Pin};
 use std::collections::BTreeMap;
 use thiserror::Error;
 
+const LOG_TARGET: &str = "provisioner";
+
 struct ProvisioningJob {
 	relay_parent: Hash,
 	sender: mpsc::Sender<FromJob>,
@@ -203,7 +205,7 @@ impl ProvisioningJob {
 					)
 					.await
 					{
-						log::warn!(target: "provisioner", "failed to assemble or send inherent data: {:?}", err);
+						log::warn!(target: LOG_TARGET, "failed to assemble or send inherent data: {:?}", err);
 						self.metrics.on_inherent_data_request(Err(()));
 					} else {
 						self.metrics.on_inherent_data_request(Ok(()));
@@ -459,7 +461,8 @@ fn bitfields_indicate_availability(
 				// however, in practice, that would just push off an error-handling routine which would look a whole lot like this one.
 				// simpler to just handle the error internally here.
 				log::warn!(
-					target: "provisioner", "attempted to set a transverse bit at idx {} which is greater than bitfield size {}",
+					target: LOG_TARGET,
+					"attempted to set a transverse bit at idx {} which is greater than bitfield size {}",
 					validator_idx,
 					availability_len,
 				);