From 55a30ac81bf32a72e0b79ca2e7bb612344a5c43d Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 10:12:02 +0000
Subject: [PATCH 01/21] Check authority status on active leaves update

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/core/chain-selection/src/lib.rs | 67 +++++++++++++++++++++++-----
 node/service/src/overseer.rs         |  6 ++-
 2 files changed, 61 insertions(+), 12 deletions(-)

diff --git a/node/core/chain-selection/src/lib.rs b/node/core/chain-selection/src/lib.rs
index ee968496da1e..eb4c1d21e446 100644
--- a/node/core/chain-selection/src/lib.rs
+++ b/node/core/chain-selection/src/lib.rs
@@ -22,7 +22,9 @@ use polkadot_node_subsystem::{
 	messages::{ChainApiMessage, ChainSelectionMessage},
 	overseer, FromOverseer, OverseerSignal, SpawnedSubsystem, SubsystemContext, SubsystemError,
 };
+use polkadot_node_subsystem_util::Validator;
 use polkadot_primitives::v1::{BlockNumber, ConsensusLog, Hash, Header};
+use sp_keystore::SyncCryptoStorePtr;
 
 use futures::{channel::oneshot, future::Either, prelude::*};
 use kvdb::KeyValueDB;
@@ -307,13 +309,23 @@ pub struct Config {
 pub struct ChainSelectionSubsystem {
 	config: Config,
 	db: Arc<dyn KeyValueDB>,
+	keystore: SyncCryptoStorePtr,
+}
+
+/// A structure to pass arguments to the subsystem main loop.
+struct ChainSelectionSubsystemArgs<'a, Context, B> {
+	ctx: &'a mut Context,
+	backend: &'a mut B,
+	stagnant_check_interval: &'a StagnantCheckInterval,
+	clock: &'a (dyn Clock + Sync),
+	keystore: SyncCryptoStorePtr,
 }
 
 impl ChainSelectionSubsystem {
 	/// Create a new instance of the subsystem with the given config
 	/// and key-value store.
-	pub fn new(config: Config, db: Arc<dyn KeyValueDB>) -> Self {
-		ChainSelectionSubsystem { config, db }
+	pub fn new(config: Config, db: Arc<dyn KeyValueDB>, keystore: SyncCryptoStorePtr) -> Self {
+		ChainSelectionSubsystem { config, db, keystore }
 	}
 }
 
@@ -329,9 +341,15 @@ where
 		);
 
 		SpawnedSubsystem {
-			future: run(ctx, backend, self.config.stagnant_check_interval, Box::new(SystemClock))
-				.map(Ok)
-				.boxed(),
+			future: run(
+				ctx,
+				backend,
+				self.config.stagnant_check_interval,
+				Box::new(SystemClock),
+				self.keystore,
+			)
+			.map(Ok)
+			.boxed(),
 			name: "chain-selection-subsystem",
 		}
 	}
@@ -342,13 +360,21 @@ async fn run<Context, B>(
 	mut backend: B,
 	stagnant_check_interval: StagnantCheckInterval,
 	clock: Box<dyn Clock + Send + Sync>,
+	keystore: SyncCryptoStorePtr,
 ) where
 	Context: SubsystemContext<Message = ChainSelectionMessage>,
 	Context: overseer::SubsystemContext<Message = ChainSelectionMessage>,
 	B: Backend,
 {
 	loop {
-		let res = run_until_error(&mut ctx, &mut backend, &stagnant_check_interval, &*clock).await;
+		let res = run_until_error(ChainSelectionSubsystemArgs {
+			ctx: &mut ctx,
+			backend: &mut backend,
+			stagnant_check_interval: &stagnant_check_interval,
+			clock: &*clock,
+			keystore,
+		})
+		.await;
 		match res {
 			Err(e) => {
 				e.trace();
@@ -368,18 +394,20 @@ async fn run<Context, B>(
 //
 // A return value of `Ok` indicates that an exit should be made, while non-fatal errors
 // lead to another call to this function.
-async fn run_until_error<Context, B>(
-	ctx: &mut Context,
-	backend: &mut B,
-	stagnant_check_interval: &StagnantCheckInterval,
-	clock: &(dyn Clock + Sync),
+async fn run_until_error<'a, Context, B>(
+	args: ChainSelectionSubsystemArgs<'a, Context, B>,
 ) -> Result<(), Error>
 where
 	Context: SubsystemContext<Message = ChainSelectionMessage>,
 	Context: overseer::SubsystemContext<Message = ChainSelectionMessage>,
 	B: Backend,
 {
+	let ChainSelectionSubsystemArgs { ctx, backend, stagnant_check_interval, clock, keystore } =
+		args;
+
 	let mut stagnant_check_stream = stagnant_check_interval.timeout_stream();
+	let mut is_validator = false;
+	let mut sender = ctx.sender().clone();
 	loop {
 		futures::select! {
 			msg = ctx.recv().fuse() => {
@@ -398,6 +426,23 @@ where
 							).await?;
 
 							backend.write(write_ops)?;
+
+							if is_validator != Validator::new(leaf.hash, keystore.clone(), &mut sender).await.is_ok() {
+								is_validator = !is_validator;
+								tracing::info!(
+									"👮 Authority status changed to `{}` at block #{}({})",
+									is_validator,
+									leaf.number,
+									leaf.hash
+								);
+							} else {
+								tracing::info!(
+									"🚔 Authority status is `{}` at block #{}({})",
+									is_validator,
+									leaf.number,
+									leaf.hash
+								);
+							}
 						}
 					}
 					FromOverseer::Signal(OverseerSignal::BlockFinalized(h, n)) => {
diff --git a/node/service/src/overseer.rs b/node/service/src/overseer.rs
index bbdc7692fc52..2d654e19ce54 100644
--- a/node/service/src/overseer.rs
+++ b/node/service/src/overseer.rs
@@ -281,7 +281,11 @@ where
 			authority_discovery_service.clone(),
 			Metrics::register(registry)?,
 		))
-		.chain_selection(ChainSelectionSubsystem::new(chain_selection_config, parachains_db))
+		.chain_selection(ChainSelectionSubsystem::new(
+			chain_selection_config,
+			parachains_db,
+			keystore.clone(),
+		))
 		.leaves(Vec::from_iter(
 			leaves
 				.into_iter()

From ffea18fe3ca12b27e6471ad9f44592799ec90956 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 10:12:28 +0000
Subject: [PATCH 02/21] cargo changes

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 Cargo.lock                           | 1 +
 node/core/chain-selection/Cargo.toml | 1 +
 2 files changed, 2 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index 86e93fda792c..b4a0662695ed 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6386,6 +6386,7 @@ dependencies = [
  "polkadot-node-subsystem-util",
  "polkadot-primitives",
  "sp-core",
+ "sp-keystore",
  "thiserror",
  "tracing",
 ]
diff --git a/node/core/chain-selection/Cargo.toml b/node/core/chain-selection/Cargo.toml
index 814f732dae61..ea963552a6ca 100644
--- a/node/core/chain-selection/Cargo.toml
+++ b/node/core/chain-selection/Cargo.toml
@@ -16,6 +16,7 @@ polkadot-node-subsystem-util = { path = "../../subsystem-util" }
 kvdb = "0.10.0"
 thiserror = "1.0.30"
 parity-scale-codec = "2"
+sp-keystore = { git = "https://github.com/paritytech/substrate", branch = "master" }
 
 [dev-dependencies]
 polkadot-node-subsystem-test-helpers = { path = "../../subsystem-test-helpers" }

From 5bd56bb367ec0b01ecca04498b3974ab67bf3189 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 10:49:15 +0000
Subject: [PATCH 03/21] Fix tests

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 Cargo.lock                             | 1 +
 node/core/chain-selection/Cargo.toml   | 1 +
 node/core/chain-selection/src/tests.rs | 3 +++
 3 files changed, 5 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index b4a0662695ed..550265cd2a11 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6385,6 +6385,7 @@ dependencies = [
  "polkadot-node-subsystem-test-helpers",
  "polkadot-node-subsystem-util",
  "polkadot-primitives",
+ "sc-keystore",
  "sp-core",
  "sp-keystore",
  "thiserror",
diff --git a/node/core/chain-selection/Cargo.toml b/node/core/chain-selection/Cargo.toml
index ea963552a6ca..189cd187f45f 100644
--- a/node/core/chain-selection/Cargo.toml
+++ b/node/core/chain-selection/Cargo.toml
@@ -24,3 +24,4 @@ sp-core = { git = "https://github.com/paritytech/substrate", branch = "master" }
 parking_lot = "0.11"
 assert_matches = "1"
 kvdb-memorydb = "0.10.0"
+sc-keystore = { git = "https://github.com/paritytech/substrate", branch = "master" }
diff --git a/node/core/chain-selection/src/tests.rs b/node/core/chain-selection/src/tests.rs
index 396e11520733..fc22366bb5b3 100644
--- a/node/core/chain-selection/src/tests.rs
+++ b/node/core/chain-selection/src/tests.rs
@@ -33,6 +33,7 @@ use assert_matches::assert_matches;
 use futures::channel::oneshot;
 use parity_scale_codec::Encode;
 use parking_lot::Mutex;
+use sc_keystore::LocalKeystore;
 use sp_core::testing::TaskExecutor;
 
 use polkadot_node_subsystem::{
@@ -234,6 +235,7 @@ fn test_harness<T: Future<Output = VirtualOverseer>>(
 ) {
 	let pool = TaskExecutor::new();
 	let (context, virtual_overseer) = test_helpers::make_subsystem_context(pool);
+	let keystore = Arc::new(LocalKeystore::in_memory()) as SyncCryptoStorePtr;
 
 	let backend = TestBackend::default();
 	let clock = TestClock::new(0);
@@ -242,6 +244,7 @@ fn test_harness<T: Future<Output = VirtualOverseer>>(
 		backend.clone(),
 		StagnantCheckInterval::new(TEST_STAGNANT_INTERVAL),
 		Box::new(clock.clone()),
+		keystore,
 	);
 
 	let test_fut = test(backend, clock, virtual_overseer);

From 1234ab1326a05f799d921f763d6761a3d13da6c9 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 14:33:53 +0000
Subject: [PATCH 04/21] Add metric for authority status

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/lib.rs     | 22 +++++++-
 node/network/gossip-support/src/metrics.rs | 61 ++++++++++++++++++++++
 node/service/src/overseer.rs               |  1 +
 3 files changed, 82 insertions(+), 2 deletions(-)
 create mode 100644 node/network/gossip-support/src/metrics.rs

diff --git a/node/network/gossip-support/src/lib.rs b/node/network/gossip-support/src/lib.rs
index c01c816dafcd..3a4629099df4 100644
--- a/node/network/gossip-support/src/lib.rs
+++ b/node/network/gossip-support/src/lib.rs
@@ -57,6 +57,10 @@ use polkadot_primitives::v1::{AuthorityDiscoveryId, Hash, SessionIndex};
 #[cfg(test)]
 mod tests;
 
+mod metrics;
+
+use metrics::Metrics;
+
 const LOG_TARGET: &str = "parachain::gossip-support";
 // How much time should we wait to reissue a connection request
 // since the last authority discovery resolution failure.
@@ -104,6 +108,9 @@ pub struct GossipSupport<AD> {
 	connected_authorities_by_peer_id: HashMap<PeerId, HashSet<AuthorityDiscoveryId>>,
 	/// Authority discovery service.
 	authority_discovery: AD,
+
+	/// Subsystem metrics.
+	metrics: Metrics,
 }
 
 impl<AD> GossipSupport<AD>
@@ -111,7 +118,10 @@ where
 	AD: AuthorityDiscovery,
 {
 	/// Create a new instance of the [`GossipSupport`] subsystem.
-	pub fn new(keystore: SyncCryptoStorePtr, authority_discovery: AD) -> Self {
+	pub fn new(keystore: SyncCryptoStorePtr, authority_discovery: AD, metrics: Metrics) -> Self {
+		// Initialize the `polkadot_node_is_authority` metric.
+		metrics.on_is_not_authority();
+
 		Self {
 			keystore,
 			last_session_index: None,
@@ -121,6 +131,7 @@ where
 			connected_authorities: HashMap::new(),
 			connected_authorities_by_peer_id: HashMap::new(),
 			authority_discovery,
+			metrics,
 		}
 	}
 
@@ -212,7 +223,14 @@ where
 				}
 
 				let all_authorities = determine_relevant_authorities(ctx, relay_parent).await?;
-				let our_index = ensure_i_am_an_authority(&self.keystore, &all_authorities).await?;
+				let our_index = ensure_i_am_an_authority(&self.keystore, &all_authorities)
+					.await
+					.map_err(|e| {
+						self.metrics.on_is_not_authority();
+						e
+					})?;
+				self.metrics.on_is_authority();
+
 				let other_authorities = {
 					let mut authorities = all_authorities.clone();
 					authorities.swap_remove(our_index);
diff --git a/node/network/gossip-support/src/metrics.rs b/node/network/gossip-support/src/metrics.rs
new file mode 100644
index 000000000000..8442db960175
--- /dev/null
+++ b/node/network/gossip-support/src/metrics.rs
@@ -0,0 +1,61 @@
+// Copyright 2021 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+use polkadot_node_subsystem_util::{
+	metrics,
+	metrics::{
+		prometheus,
+		prometheus::{Gauge, PrometheusError, Registry, U64},
+	},
+};
+
+/// Dispute Distribution metrics.
+#[derive(Clone, Default)]
+pub struct Metrics(Option<MetricsInner>);
+
+#[derive(Clone)]
+struct MetricsInner {
+	/// Tracks authority status.
+	is_authority: Gauge<U64>,
+}
+
+impl Metrics {
+	/// Set the authority flag.
+	pub fn on_is_authority(&self) {
+		if let Some(metrics) = &self.0 {
+			metrics.is_authority.set(1);
+		}
+	}
+
+	/// Unset the authority flag.
+	pub fn on_is_not_authority(&self) {
+		if let Some(metrics) = &self.0 {
+			metrics.is_authority.set(0);
+		}
+	}
+}
+
+impl metrics::Metrics for Metrics {
+	fn try_register(registry: &Registry) -> Result<Self, PrometheusError> {
+		let metrics = MetricsInner {
+			is_authority: prometheus::register(
+				Gauge::new("polkadot_node_is_authority", "Tracks the node authority status.")?,
+				registry,
+			)?,
+		};
+		Ok(Metrics(Some(metrics)))
+	}
+}
diff --git a/node/service/src/overseer.rs b/node/service/src/overseer.rs
index 2d654e19ce54..6d56f64b9def 100644
--- a/node/service/src/overseer.rs
+++ b/node/service/src/overseer.rs
@@ -264,6 +264,7 @@ where
 		.gossip_support(GossipSupportSubsystem::new(
 			keystore.clone(),
 			authority_discovery_service.clone(),
+			Metrics::register(registry)?,
 		))
 		.dispute_coordinator(if disputes_enabled {
 			DisputeCoordinatorSubsystem::new(

From a5d3b6ea966fdada056acafd4a82d0b3dabce20a Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 14:34:44 +0000
Subject: [PATCH 05/21] Revert "Fix tests"

This reverts commit 5bd56bb367ec0b01ecca04498b3974ab67bf3189.
---
 Cargo.lock                             | 1 -
 node/core/chain-selection/Cargo.toml   | 1 -
 node/core/chain-selection/src/tests.rs | 3 ---
 3 files changed, 5 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 550265cd2a11..b4a0662695ed 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6385,7 +6385,6 @@ dependencies = [
  "polkadot-node-subsystem-test-helpers",
  "polkadot-node-subsystem-util",
  "polkadot-primitives",
- "sc-keystore",
  "sp-core",
  "sp-keystore",
  "thiserror",
diff --git a/node/core/chain-selection/Cargo.toml b/node/core/chain-selection/Cargo.toml
index 189cd187f45f..ea963552a6ca 100644
--- a/node/core/chain-selection/Cargo.toml
+++ b/node/core/chain-selection/Cargo.toml
@@ -24,4 +24,3 @@ sp-core = { git = "https://github.com/paritytech/substrate", branch = "master" }
 parking_lot = "0.11"
 assert_matches = "1"
 kvdb-memorydb = "0.10.0"
-sc-keystore = { git = "https://github.com/paritytech/substrate", branch = "master" }
diff --git a/node/core/chain-selection/src/tests.rs b/node/core/chain-selection/src/tests.rs
index fc22366bb5b3..396e11520733 100644
--- a/node/core/chain-selection/src/tests.rs
+++ b/node/core/chain-selection/src/tests.rs
@@ -33,7 +33,6 @@ use assert_matches::assert_matches;
 use futures::channel::oneshot;
 use parity_scale_codec::Encode;
 use parking_lot::Mutex;
-use sc_keystore::LocalKeystore;
 use sp_core::testing::TaskExecutor;
 
 use polkadot_node_subsystem::{
@@ -235,7 +234,6 @@ fn test_harness<T: Future<Output = VirtualOverseer>>(
 ) {
 	let pool = TaskExecutor::new();
 	let (context, virtual_overseer) = test_helpers::make_subsystem_context(pool);
-	let keystore = Arc::new(LocalKeystore::in_memory()) as SyncCryptoStorePtr;
 
 	let backend = TestBackend::default();
 	let clock = TestClock::new(0);
@@ -244,7 +242,6 @@ fn test_harness<T: Future<Output = VirtualOverseer>>(
 		backend.clone(),
 		StagnantCheckInterval::new(TEST_STAGNANT_INTERVAL),
 		Box::new(clock.clone()),
-		keystore,
 	);
 
 	let test_fut = test(backend, clock, virtual_overseer);

From cf824f3625a4ae327d8efa20e1ec4f70e2e43122 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 14:35:03 +0000
Subject: [PATCH 06/21] Revert "cargo changes"

This reverts commit ffea18fe3ca12b27e6471ad9f44592799ec90956.
---
 Cargo.lock                           | 1 -
 node/core/chain-selection/Cargo.toml | 1 -
 2 files changed, 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index b4a0662695ed..86e93fda792c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6386,7 +6386,6 @@ dependencies = [
  "polkadot-node-subsystem-util",
  "polkadot-primitives",
  "sp-core",
- "sp-keystore",
  "thiserror",
  "tracing",
 ]
diff --git a/node/core/chain-selection/Cargo.toml b/node/core/chain-selection/Cargo.toml
index ea963552a6ca..814f732dae61 100644
--- a/node/core/chain-selection/Cargo.toml
+++ b/node/core/chain-selection/Cargo.toml
@@ -16,7 +16,6 @@ polkadot-node-subsystem-util = { path = "../../subsystem-util" }
 kvdb = "0.10.0"
 thiserror = "1.0.30"
 parity-scale-codec = "2"
-sp-keystore = { git = "https://github.com/paritytech/substrate", branch = "master" }
 
 [dev-dependencies]
 polkadot-node-subsystem-test-helpers = { path = "../../subsystem-test-helpers" }

From 625cc2f0c78a556e16429285198bd99889efe578 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 14:35:14 +0000
Subject: [PATCH 07/21] Revert "Check authority status on active leaves update"

This reverts commit 55a30ac81bf32a72e0b79ca2e7bb612344a5c43d.
---
 node/core/chain-selection/src/lib.rs | 67 +++++-----------------------
 node/service/src/overseer.rs         |  6 +--
 2 files changed, 12 insertions(+), 61 deletions(-)

diff --git a/node/core/chain-selection/src/lib.rs b/node/core/chain-selection/src/lib.rs
index eb4c1d21e446..ee968496da1e 100644
--- a/node/core/chain-selection/src/lib.rs
+++ b/node/core/chain-selection/src/lib.rs
@@ -22,9 +22,7 @@ use polkadot_node_subsystem::{
 	messages::{ChainApiMessage, ChainSelectionMessage},
 	overseer, FromOverseer, OverseerSignal, SpawnedSubsystem, SubsystemContext, SubsystemError,
 };
-use polkadot_node_subsystem_util::Validator;
 use polkadot_primitives::v1::{BlockNumber, ConsensusLog, Hash, Header};
-use sp_keystore::SyncCryptoStorePtr;
 
 use futures::{channel::oneshot, future::Either, prelude::*};
 use kvdb::KeyValueDB;
@@ -309,23 +307,13 @@ pub struct Config {
 pub struct ChainSelectionSubsystem {
 	config: Config,
 	db: Arc<dyn KeyValueDB>,
-	keystore: SyncCryptoStorePtr,
-}
-
-/// A structure to pass arguments to the subsystem main loop.
-struct ChainSelectionSubsystemArgs<'a, Context, B> {
-	ctx: &'a mut Context,
-	backend: &'a mut B,
-	stagnant_check_interval: &'a StagnantCheckInterval,
-	clock: &'a (dyn Clock + Sync),
-	keystore: SyncCryptoStorePtr,
 }
 
 impl ChainSelectionSubsystem {
 	/// Create a new instance of the subsystem with the given config
 	/// and key-value store.
-	pub fn new(config: Config, db: Arc<dyn KeyValueDB>, keystore: SyncCryptoStorePtr) -> Self {
-		ChainSelectionSubsystem { config, db, keystore }
+	pub fn new(config: Config, db: Arc<dyn KeyValueDB>) -> Self {
+		ChainSelectionSubsystem { config, db }
 	}
 }
 
@@ -341,15 +329,9 @@ where
 		);
 
 		SpawnedSubsystem {
-			future: run(
-				ctx,
-				backend,
-				self.config.stagnant_check_interval,
-				Box::new(SystemClock),
-				self.keystore,
-			)
-			.map(Ok)
-			.boxed(),
+			future: run(ctx, backend, self.config.stagnant_check_interval, Box::new(SystemClock))
+				.map(Ok)
+				.boxed(),
 			name: "chain-selection-subsystem",
 		}
 	}
@@ -360,21 +342,13 @@ async fn run<Context, B>(
 	mut backend: B,
 	stagnant_check_interval: StagnantCheckInterval,
 	clock: Box<dyn Clock + Send + Sync>,
-	keystore: SyncCryptoStorePtr,
 ) where
 	Context: SubsystemContext<Message = ChainSelectionMessage>,
 	Context: overseer::SubsystemContext<Message = ChainSelectionMessage>,
 	B: Backend,
 {
 	loop {
-		let res = run_until_error(ChainSelectionSubsystemArgs {
-			ctx: &mut ctx,
-			backend: &mut backend,
-			stagnant_check_interval: &stagnant_check_interval,
-			clock: &*clock,
-			keystore,
-		})
-		.await;
+		let res = run_until_error(&mut ctx, &mut backend, &stagnant_check_interval, &*clock).await;
 		match res {
 			Err(e) => {
 				e.trace();
@@ -394,20 +368,18 @@ async fn run<Context, B>(
 //
 // A return value of `Ok` indicates that an exit should be made, while non-fatal errors
 // lead to another call to this function.
-async fn run_until_error<'a, Context, B>(
-	args: ChainSelectionSubsystemArgs<'a, Context, B>,
+async fn run_until_error<Context, B>(
+	ctx: &mut Context,
+	backend: &mut B,
+	stagnant_check_interval: &StagnantCheckInterval,
+	clock: &(dyn Clock + Sync),
 ) -> Result<(), Error>
 where
 	Context: SubsystemContext<Message = ChainSelectionMessage>,
 	Context: overseer::SubsystemContext<Message = ChainSelectionMessage>,
 	B: Backend,
 {
-	let ChainSelectionSubsystemArgs { ctx, backend, stagnant_check_interval, clock, keystore } =
-		args;
-
 	let mut stagnant_check_stream = stagnant_check_interval.timeout_stream();
-	let mut is_validator = false;
-	let mut sender = ctx.sender().clone();
 	loop {
 		futures::select! {
 			msg = ctx.recv().fuse() => {
@@ -426,23 +398,6 @@ where
 							).await?;
 
 							backend.write(write_ops)?;
-
-							if is_validator != Validator::new(leaf.hash, keystore.clone(), &mut sender).await.is_ok() {
-								is_validator = !is_validator;
-								tracing::info!(
-									"👮 Authority status changed to `{}` at block #{}({})",
-									is_validator,
-									leaf.number,
-									leaf.hash
-								);
-							} else {
-								tracing::info!(
-									"🚔 Authority status is `{}` at block #{}({})",
-									is_validator,
-									leaf.number,
-									leaf.hash
-								);
-							}
 						}
 					}
 					FromOverseer::Signal(OverseerSignal::BlockFinalized(h, n)) => {
diff --git a/node/service/src/overseer.rs b/node/service/src/overseer.rs
index 6d56f64b9def..58be883fa199 100644
--- a/node/service/src/overseer.rs
+++ b/node/service/src/overseer.rs
@@ -282,11 +282,7 @@ where
 			authority_discovery_service.clone(),
 			Metrics::register(registry)?,
 		))
-		.chain_selection(ChainSelectionSubsystem::new(
-			chain_selection_config,
-			parachains_db,
-			keystore.clone(),
-		))
+		.chain_selection(ChainSelectionSubsystem::new(chain_selection_config, parachains_db))
 		.leaves(Vec::from_iter(
 			leaves
 				.into_iter()

From d8304fdbd230dabaa0547395112358d819971639 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 15:09:52 +0000
Subject: [PATCH 08/21] Test fixups

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/metrics.rs | 6 ++++++
 node/network/gossip-support/src/tests.rs   | 6 +++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/node/network/gossip-support/src/metrics.rs b/node/network/gossip-support/src/metrics.rs
index 8442db960175..72601985795f 100644
--- a/node/network/gossip-support/src/metrics.rs
+++ b/node/network/gossip-support/src/metrics.rs
@@ -33,6 +33,12 @@ struct MetricsInner {
 }
 
 impl Metrics {
+	#[cfg(test)]
+	/// Dummy constructor for testing.
+	pub fn new_dummy() -> Self {
+		Self(None)
+	}
+
 	/// Set the authority flag.
 	pub fn on_is_authority(&self) {
 		if let Some(metrics) = &self.0 {
diff --git a/node/network/gossip-support/src/tests.rs b/node/network/gossip-support/src/tests.rs
index a3267a1daa11..0ebd729bbda3 100644
--- a/node/network/gossip-support/src/tests.rs
+++ b/node/network/gossip-support/src/tests.rs
@@ -126,7 +126,11 @@ async fn get_other_authorities_addrs_map() -> HashMap<AuthorityDiscoveryId, Hash
 }
 
 fn make_subsystem() -> GossipSupport<MockAuthorityDiscovery> {
-	GossipSupport::new(make_ferdie_keystore(), MOCK_AUTHORITY_DISCOVERY.clone())
+	GossipSupport::new(
+		make_ferdie_keystore(),
+		MOCK_AUTHORITY_DISCOVERY.clone(),
+		Metrics::new_dummy(),
+	)
 }
 
 fn test_harness<T: Future<Output = VirtualOverseer>, AD: AuthorityDiscovery>(

From a44d8bf6b6333d59c9b3bc45d9e1a1790fda4cbd Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 15:27:00 +0000
Subject: [PATCH 09/21] fix

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/metrics.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/node/network/gossip-support/src/metrics.rs b/node/network/gossip-support/src/metrics.rs
index 72601985795f..97924fdad994 100644
--- a/node/network/gossip-support/src/metrics.rs
+++ b/node/network/gossip-support/src/metrics.rs
@@ -33,8 +33,8 @@ struct MetricsInner {
 }
 
 impl Metrics {
-	#[cfg(test)]
 	/// Dummy constructor for testing.
+	#[cfg(test)]
 	pub fn new_dummy() -> Self {
 		Self(None)
 	}

From 404bae80ed1688d6a2113d877415a6ea5141ddaa Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 20:05:17 +0000
Subject: [PATCH 10/21] update

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/lib.rs | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/node/network/gossip-support/src/lib.rs b/node/network/gossip-support/src/lib.rs
index 3a4629099df4..862b914a4f63 100644
--- a/node/network/gossip-support/src/lib.rs
+++ b/node/network/gossip-support/src/lib.rs
@@ -220,16 +220,16 @@ where
 						"New session detected",
 					);
 					self.last_session_index = Some(session_index);
+
+					// Update the authority status metric on every new session.
+					match util::Validator::new(leaf, self.keystore.clone(), ctx.sender()).await {
+						Ok(_) => self.metrics.on_is_authority(),
+						Err(_) => self.metrics.on_is_not_authority(),
+					}
 				}
 
 				let all_authorities = determine_relevant_authorities(ctx, relay_parent).await?;
-				let our_index = ensure_i_am_an_authority(&self.keystore, &all_authorities)
-					.await
-					.map_err(|e| {
-						self.metrics.on_is_not_authority();
-						e
-					})?;
-				self.metrics.on_is_authority();
+				let our_index = ensure_i_am_an_authority(&self.keystore, &all_authorities).await?;
 
 				let other_authorities = {
 					let mut authorities = all_authorities.clone();

From d30205f40fa3cc58e194ced7245a1439f852275d Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Wed, 12 Jan 2022 20:07:54 +0000
Subject: [PATCH 11/21] undo damage

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/lib.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/node/network/gossip-support/src/lib.rs b/node/network/gossip-support/src/lib.rs
index 862b914a4f63..de6e4afd5a28 100644
--- a/node/network/gossip-support/src/lib.rs
+++ b/node/network/gossip-support/src/lib.rs
@@ -230,7 +230,6 @@ where
 
 				let all_authorities = determine_relevant_authorities(ctx, relay_parent).await?;
 				let our_index = ensure_i_am_an_authority(&self.keystore, &all_authorities).await?;
-
 				let other_authorities = {
 					let mut authorities = all_authorities.clone();
 					authorities.swap_remove(our_index);

From b0a3428e6d710237df9a9dbb606e813d8d45c760 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 09:29:13 +0000
Subject: [PATCH 12/21] dont update status on runtime errors

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/lib.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/node/network/gossip-support/src/lib.rs b/node/network/gossip-support/src/lib.rs
index de6e4afd5a28..936e0ff9e7f6 100644
--- a/node/network/gossip-support/src/lib.rs
+++ b/node/network/gossip-support/src/lib.rs
@@ -224,7 +224,9 @@ where
 					// Update the authority status metric on every new session.
 					match util::Validator::new(leaf, self.keystore.clone(), ctx.sender()).await {
 						Ok(_) => self.metrics.on_is_authority(),
-						Err(_) => self.metrics.on_is_not_authority(),
+						Err(util::Error::NotAValidator) => self.metrics.on_is_not_authority(),
+						// Don't update on runtime errors.
+						Err(_) => {},
 					}
 				}
 

From 65aa234619ee875045b2c2b83ae8c5230a9046e8 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 11:35:53 +0000
Subject: [PATCH 13/21] Fix tests

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/lib.rs     |  6 ++--
 node/network/gossip-support/src/metrics.rs |  4 +--
 node/network/gossip-support/src/tests.rs   | 35 ++++++++++++++++++++++
 3 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/node/network/gossip-support/src/lib.rs b/node/network/gossip-support/src/lib.rs
index 936e0ff9e7f6..d6815dffa2ac 100644
--- a/node/network/gossip-support/src/lib.rs
+++ b/node/network/gossip-support/src/lib.rs
@@ -120,7 +120,7 @@ where
 	/// Create a new instance of the [`GossipSupport`] subsystem.
 	pub fn new(keystore: SyncCryptoStorePtr, authority_discovery: AD, metrics: Metrics) -> Self {
 		// Initialize the `polkadot_node_is_authority` metric.
-		metrics.on_is_not_authority();
+		metrics.on_role_is_not_authority();
 
 		Self {
 			keystore,
@@ -223,8 +223,8 @@ where
 
 					// Update the authority status metric on every new session.
 					match util::Validator::new(leaf, self.keystore.clone(), ctx.sender()).await {
-						Ok(_) => self.metrics.on_is_authority(),
-						Err(util::Error::NotAValidator) => self.metrics.on_is_not_authority(),
+						Ok(_) => self.metrics.on_role_is_authority(),
+						Err(util::Error::NotAValidator) => self.metrics.on_role_is_not_authority(),
 						// Don't update on runtime errors.
 						Err(_) => {},
 					}
diff --git a/node/network/gossip-support/src/metrics.rs b/node/network/gossip-support/src/metrics.rs
index 97924fdad994..907983fd99e6 100644
--- a/node/network/gossip-support/src/metrics.rs
+++ b/node/network/gossip-support/src/metrics.rs
@@ -40,14 +40,14 @@ impl Metrics {
 	}
 
 	/// Set the authority flag.
-	pub fn on_is_authority(&self) {
+	pub fn on_role_is_authority(&self) {
 		if let Some(metrics) = &self.0 {
 			metrics.is_authority.set(1);
 		}
 	}
 
 	/// Unset the authority flag.
-	pub fn on_is_not_authority(&self) {
+	pub fn on_role_is_not_authority(&self) {
 		if let Some(metrics) = &self.0 {
 			metrics.is_authority.set(0);
 		}
diff --git a/node/network/gossip-support/src/tests.rs b/node/network/gossip-support/src/tests.rs
index 0ebd729bbda3..b6cae89b50ea 100644
--- a/node/network/gossip-support/src/tests.rs
+++ b/node/network/gossip-support/src/tests.rs
@@ -218,6 +218,32 @@ async fn test_neighbors(overseer: &mut VirtualOverseer) {
 	);
 }
 
+// Helper function to test the `Validator::new()` call from inside ActiveLeavesUpdate
+// handler.
+async fn check_validator_status(overseer: &mut VirtualOverseer, hash: Hash) {
+	assert_matches!(
+		overseer_recv(overseer).await,
+		AllMessages::RuntimeApi(RuntimeApiMessage::Request(
+			relay_parent,
+			RuntimeApiRequest::Validators(sender),
+		)) => {
+			assert_eq!(relay_parent, hash);
+			sender.send(Ok(Vec::new())).unwrap();
+		}
+	);
+
+	assert_matches!(
+		overseer_recv(overseer).await,
+		AllMessages::RuntimeApi(RuntimeApiMessage::Request(
+			relay_parent,
+			RuntimeApiRequest::SessionIndexForChild(tx),
+		)) => {
+			assert_eq!(relay_parent, hash);
+			tx.send(Ok(2)).unwrap();
+		}
+	);
+}
+
 #[test]
 fn issues_a_connection_request_on_new_session() {
 	let hash = Hash::repeat_byte(0xAA);
@@ -234,6 +260,9 @@ fn issues_a_connection_request_on_new_session() {
 				tx.send(Ok(1)).unwrap();
 			}
 		);
+
+		check_validator_status(overseer, hash).await;
+
 		assert_matches!(
 			overseer_recv(overseer).await,
 			AllMessages::RuntimeApi(RuntimeApiMessage::Request(
@@ -300,6 +329,9 @@ fn issues_a_connection_request_on_new_session() {
 				tx.send(Ok(2)).unwrap();
 			}
 		);
+
+		check_validator_status(overseer, hash).await;
+
 		assert_matches!(
 			overseer_recv(overseer).await,
 			AllMessages::RuntimeApi(RuntimeApiMessage::Request(
@@ -382,6 +414,9 @@ fn issues_a_connection_request_when_last_request_was_mostly_unresolved() {
 					tx.send(Ok(1)).unwrap();
 				}
 			);
+
+			check_validator_status(overseer, hash).await;
+
 			assert_matches!(
 				overseer_recv(overseer).await,
 				AllMessages::RuntimeApi(RuntimeApiMessage::Request(

From 8a29350969780213caf3239fbc03045fdf2930ee Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 11:40:42 +0000
Subject: [PATCH 14/21] fix inconsistency

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/tests.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/node/network/gossip-support/src/tests.rs b/node/network/gossip-support/src/tests.rs
index b6cae89b50ea..0bb6ebd831e3 100644
--- a/node/network/gossip-support/src/tests.rs
+++ b/node/network/gossip-support/src/tests.rs
@@ -236,10 +236,10 @@ async fn check_validator_status(overseer: &mut VirtualOverseer, hash: Hash) {
 		overseer_recv(overseer).await,
 		AllMessages::RuntimeApi(RuntimeApiMessage::Request(
 			relay_parent,
-			RuntimeApiRequest::SessionIndexForChild(tx),
+			RuntimeApiRequest::SessionIndexForChild(sender),
 		)) => {
 			assert_eq!(relay_parent, hash);
-			tx.send(Ok(2)).unwrap();
+			sender.send(Ok(2)).unwrap();
 		}
 	);
 }

From d05bfc921564a010e69444cbef71cf72d729a077 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 15:49:04 +0000
Subject: [PATCH 15/21] Review feedback

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/lib.rs     | 64 +++++++++++++++++----
 node/network/gossip-support/src/metrics.rs | 35 ++++++++++--
 node/network/gossip-support/src/tests.rs   | 65 +++++++++++-----------
 primitives/src/v2/mod.rs                   |  3 +-
 4 files changed, 117 insertions(+), 50 deletions(-)

diff --git a/node/network/gossip-support/src/lib.rs b/node/network/gossip-support/src/lib.rs
index d6815dffa2ac..e035353f8f82 100644
--- a/node/network/gossip-support/src/lib.rs
+++ b/node/network/gossip-support/src/lib.rs
@@ -49,7 +49,7 @@ use polkadot_node_subsystem::{
 		RuntimeApiRequest,
 	},
 	overseer, ActiveLeavesUpdate, FromOverseer, OverseerSignal, SpawnedSubsystem, SubsystemContext,
-	SubsystemError,
+	SubsystemError, SubsystemSender,
 };
 use polkadot_node_subsystem_util as util;
 use polkadot_primitives::v1::{AuthorityDiscoveryId, Hash, SessionIndex};
@@ -119,8 +119,9 @@ where
 {
 	/// Create a new instance of the [`GossipSupport`] subsystem.
 	pub fn new(keystore: SyncCryptoStorePtr, authority_discovery: AD, metrics: Metrics) -> Self {
-		// Initialize the `polkadot_node_is_authority` metric.
-		metrics.on_role_is_not_authority();
+		// Initialize metrics to `0`.
+		metrics.on_is_not_authority();
+		metrics.on_is_not_parachain_validator();
 
 		Self {
 			keystore,
@@ -220,14 +221,6 @@ where
 						"New session detected",
 					);
 					self.last_session_index = Some(session_index);
-
-					// Update the authority status metric on every new session.
-					match util::Validator::new(leaf, self.keystore.clone(), ctx.sender()).await {
-						Ok(_) => self.metrics.on_role_is_authority(),
-						Err(util::Error::NotAValidator) => self.metrics.on_role_is_not_authority(),
-						// Don't update on runtime errors.
-						Err(_) => {},
-					}
 				}
 
 				let all_authorities = determine_relevant_authorities(ctx, relay_parent).await?;
@@ -242,10 +235,59 @@ where
 
 				if is_new_session {
 					update_gossip_topology(ctx, our_index, all_authorities, relay_parent).await?;
+					self.update_authority_status_metrics(leaf, ctx.sender()).await?;
 				}
 			}
 		}
+		Ok(())
+	}
 
+	async fn update_authority_status_metrics(
+		&mut self,
+		leaf: Hash,
+		sender: &mut impl SubsystemSender,
+	) -> Result<(), util::Error> {
+		if let Some(session_info) = util::request_session_info(
+			leaf,
+			self.last_session_index
+				.expect("Last session index is always set on every session index change"),
+			sender,
+		)
+		.await
+		.await??
+		{
+			let maybe_index = match ensure_i_am_an_authority(
+				&self.keystore,
+				&session_info.discovery_keys,
+			)
+			.await
+			{
+				Ok(index) => {
+					self.metrics.on_is_authority();
+					Some(index)
+				},
+				Err(util::Error::NotAValidator) => {
+					self.metrics.on_is_not_authority();
+					None
+				},
+				// Don't update on runtime errors.
+				Err(_) => None,
+			};
+
+			if let Some(validator_index) = maybe_index {
+				// The subset of authorities participating in parachain consensus.
+				let parachain_validators_this_session = session_info.validators;
+
+				// First `maxValidators` entries are the parachain validators. We'll check
+				// if our index is in this set to avoid searching for the keys.
+				// https://github.com/paritytech/polkadot/blob/a52dca2be7840b23c19c153cf7e110b1e3e475f8/runtime/parachains/src/configuration.rs#L148
+				if validator_index < parachain_validators_this_session.len() {
+					self.metrics.on_is_parachain_validator();
+				} else {
+					self.metrics.on_is_not_parachain_validator();
+				}
+			}
+		}
 		Ok(())
 	}
 
diff --git a/node/network/gossip-support/src/metrics.rs b/node/network/gossip-support/src/metrics.rs
index 907983fd99e6..67aa258921d8 100644
--- a/node/network/gossip-support/src/metrics.rs
+++ b/node/network/gossip-support/src/metrics.rs
@@ -28,8 +28,10 @@ pub struct Metrics(Option<MetricsInner>);
 
 #[derive(Clone)]
 struct MetricsInner {
-	/// Tracks authority status.
+	/// Tracks authority status for producing relay chain blocks.
 	is_authority: Gauge<U64>,
+	/// Tracks authority status for parachain approval checking.
+	is_parachain_validator: Gauge<U64>,
 }
 
 impl Metrics {
@@ -39,26 +41,47 @@ impl Metrics {
 		Self(None)
 	}
 
-	/// Set the authority flag.
-	pub fn on_role_is_authority(&self) {
+	/// Set the `relaychain validator` metric.
+	pub fn on_is_authority(&self) {
 		if let Some(metrics) = &self.0 {
 			metrics.is_authority.set(1);
 		}
 	}
 
-	/// Unset the authority flag.
-	pub fn on_role_is_not_authority(&self) {
+	/// Unset the `relaychain validator` metric.
+	pub fn on_is_not_authority(&self) {
 		if let Some(metrics) = &self.0 {
 			metrics.is_authority.set(0);
 		}
 	}
+
+	/// Set the `parachain validator` metric.
+	pub fn on_is_parachain_validator(&self) {
+		if let Some(metrics) = &self.0 {
+			metrics.is_parachain_validator.set(1);
+		}
+	}
+
+	/// Unset the `parachain validator` metric.
+	pub fn on_is_not_parachain_validator(&self) {
+		if let Some(metrics) = &self.0 {
+			metrics.is_parachain_validator.set(0);
+		}
+	}
 }
 
 impl metrics::Metrics for Metrics {
 	fn try_register(registry: &Registry) -> Result<Self, PrometheusError> {
 		let metrics = MetricsInner {
 			is_authority: prometheus::register(
-				Gauge::new("polkadot_node_is_authority", "Tracks the node authority status.")?,
+				Gauge::new("polkadot_node_is_authority", "Tracks the node authority status across sessions. \
+				An authority is any node that is a potential block producer in a session.")?,
+				registry,
+			)?,
+			is_parachain_validator: prometheus::register(
+				Gauge::new("polkadot_node_is_parachain_validator", 
+				"Tracks the node parachain validator status across sessions. Parachain validators are a \
+				subset of authorities that perform approval checking of all parachain candidates in a session.")?,
 				registry,
 			)?,
 		};
diff --git a/node/network/gossip-support/src/tests.rs b/node/network/gossip-support/src/tests.rs
index 0bb6ebd831e3..d2c3b888e7a0 100644
--- a/node/network/gossip-support/src/tests.rs
+++ b/node/network/gossip-support/src/tests.rs
@@ -218,32 +218,6 @@ async fn test_neighbors(overseer: &mut VirtualOverseer) {
 	);
 }
 
-// Helper function to test the `Validator::new()` call from inside ActiveLeavesUpdate
-// handler.
-async fn check_validator_status(overseer: &mut VirtualOverseer, hash: Hash) {
-	assert_matches!(
-		overseer_recv(overseer).await,
-		AllMessages::RuntimeApi(RuntimeApiMessage::Request(
-			relay_parent,
-			RuntimeApiRequest::Validators(sender),
-		)) => {
-			assert_eq!(relay_parent, hash);
-			sender.send(Ok(Vec::new())).unwrap();
-		}
-	);
-
-	assert_matches!(
-		overseer_recv(overseer).await,
-		AllMessages::RuntimeApi(RuntimeApiMessage::Request(
-			relay_parent,
-			RuntimeApiRequest::SessionIndexForChild(sender),
-		)) => {
-			assert_eq!(relay_parent, hash);
-			sender.send(Ok(2)).unwrap();
-		}
-	);
-}
-
 #[test]
 fn issues_a_connection_request_on_new_session() {
 	let hash = Hash::repeat_byte(0xAA);
@@ -261,8 +235,6 @@ fn issues_a_connection_request_on_new_session() {
 			}
 		);
 
-		check_validator_status(overseer, hash).await;
-
 		assert_matches!(
 			overseer_recv(overseer).await,
 			AllMessages::RuntimeApi(RuntimeApiMessage::Request(
@@ -287,6 +259,17 @@ fn issues_a_connection_request_on_new_session() {
 
 		test_neighbors(overseer).await;
 
+		assert_matches!(
+			overseer_recv(overseer).await,
+			AllMessages::RuntimeApi(RuntimeApiMessage::Request(
+				relay_parent,
+				RuntimeApiRequest::SessionInfo(1, sender),
+			)) => {
+				assert_eq!(relay_parent, hash);
+				sender.send(Ok(Some(polkadot_primitives::v2::SessionInfo::default()))).unwrap();
+			}
+		);
+
 		virtual_overseer
 	});
 
@@ -330,8 +313,6 @@ fn issues_a_connection_request_on_new_session() {
 			}
 		);
 
-		check_validator_status(overseer, hash).await;
-
 		assert_matches!(
 			overseer_recv(overseer).await,
 			AllMessages::RuntimeApi(RuntimeApiMessage::Request(
@@ -356,6 +337,17 @@ fn issues_a_connection_request_on_new_session() {
 
 		test_neighbors(overseer).await;
 
+		assert_matches!(
+			overseer_recv(overseer).await,
+			AllMessages::RuntimeApi(RuntimeApiMessage::Request(
+				relay_parent,
+				RuntimeApiRequest::SessionInfo(2, sender),
+			)) => {
+				assert_eq!(relay_parent, hash);
+				sender.send(Ok(Some(polkadot_primitives::v2::SessionInfo::default()))).unwrap();
+			}
+		);
+
 		virtual_overseer
 	});
 	assert_eq!(state.last_session_index, Some(2));
@@ -415,8 +407,6 @@ fn issues_a_connection_request_when_last_request_was_mostly_unresolved() {
 				}
 			);
 
-			check_validator_status(overseer, hash).await;
-
 			assert_matches!(
 				overseer_recv(overseer).await,
 				AllMessages::RuntimeApi(RuntimeApiMessage::Request(
@@ -445,6 +435,17 @@ fn issues_a_connection_request_when_last_request_was_mostly_unresolved() {
 
 			test_neighbors(overseer).await;
 
+			assert_matches!(
+				overseer_recv(overseer).await,
+				AllMessages::RuntimeApi(RuntimeApiMessage::Request(
+					relay_parent,
+					RuntimeApiRequest::SessionInfo(1, sender),
+				)) => {
+					assert_eq!(relay_parent, hash);
+					sender.send(Ok(Some(polkadot_primitives::v2::SessionInfo::default()))).unwrap();
+				}
+			);
+
 			virtual_overseer
 		})
 	};
diff --git a/primitives/src/v2/mod.rs b/primitives/src/v2/mod.rs
index 065d5cc3c057..e07b355feb9c 100644
--- a/primitives/src/v2/mod.rs
+++ b/primitives/src/v2/mod.rs
@@ -28,7 +28,8 @@ use parity_util_mem::MallocSizeOf;
 
 /// Information about validator sets of a session.
 #[derive(Clone, Encode, Decode, RuntimeDebug, TypeInfo)]
-#[cfg_attr(feature = "std", derive(PartialEq, MallocSizeOf))]
+#[cfg_attr(feature = "std", derive(PartialEq, MallocSizeOf, Default))]
+#[cfg_attr(all(feature = "std", test), derive(Default))]
 pub struct SessionInfo {
 	/****** New in v2 *******/
 	/// All the validators actively participating in parachain consensus.

From 2d75603bee1be0e276802a8fc6dd2c3f42032c70 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 16:06:39 +0000
Subject: [PATCH 16/21] Dont derive primitive Default

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/tests.rs | 22 +++++++++++++++++++---
 primitives/src/v2/mod.rs                 |  3 +--
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/node/network/gossip-support/src/tests.rs b/node/network/gossip-support/src/tests.rs
index d2c3b888e7a0..b34fa2106e20 100644
--- a/node/network/gossip-support/src/tests.rs
+++ b/node/network/gossip-support/src/tests.rs
@@ -58,6 +58,22 @@ lazy_static! {
 		Sr25519Keyring::Charlie.public().into(),
 		Sr25519Keyring::Eve.public().into(),
 	];
+	static ref SESSION_INFO: polkadot_primitives::v2::SessionInfo =
+		polkadot_primitives::v2::SessionInfo {
+			active_validator_indices: Vec::new(),
+			random_seed: [0u8; 32],
+			dispute_period: 10,
+			validators: Vec::new(),
+			discovery_keys: Vec::new(),
+			assignment_keys: Vec::new(),
+			validator_groups: Vec::new(),
+			n_cores: 1,
+			zeroth_delay_tranche_width: 0,
+			relay_vrf_modulo_samples: 0,
+			n_delay_tranches: 0,
+			no_show_slots: 0,
+			needed_approvals: 0,
+		};
 }
 
 type VirtualOverseer = test_helpers::TestSubsystemContextHandle<GossipSupportMessage>;
@@ -266,7 +282,7 @@ fn issues_a_connection_request_on_new_session() {
 				RuntimeApiRequest::SessionInfo(1, sender),
 			)) => {
 				assert_eq!(relay_parent, hash);
-				sender.send(Ok(Some(polkadot_primitives::v2::SessionInfo::default()))).unwrap();
+				sender.send(Ok(Some(SESSION_INFO.clone()))).unwrap();
 			}
 		);
 
@@ -344,7 +360,7 @@ fn issues_a_connection_request_on_new_session() {
 				RuntimeApiRequest::SessionInfo(2, sender),
 			)) => {
 				assert_eq!(relay_parent, hash);
-				sender.send(Ok(Some(polkadot_primitives::v2::SessionInfo::default()))).unwrap();
+				sender.send(Ok(Some(SESSION_INFO.clone()))).unwrap();
 			}
 		);
 
@@ -442,7 +458,7 @@ fn issues_a_connection_request_when_last_request_was_mostly_unresolved() {
 					RuntimeApiRequest::SessionInfo(1, sender),
 				)) => {
 					assert_eq!(relay_parent, hash);
-					sender.send(Ok(Some(polkadot_primitives::v2::SessionInfo::default()))).unwrap();
+					sender.send(Ok(Some(SESSION_INFO.clone()))).unwrap();
 				}
 			);
 
diff --git a/primitives/src/v2/mod.rs b/primitives/src/v2/mod.rs
index e07b355feb9c..065d5cc3c057 100644
--- a/primitives/src/v2/mod.rs
+++ b/primitives/src/v2/mod.rs
@@ -28,8 +28,7 @@ use parity_util_mem::MallocSizeOf;
 
 /// Information about validator sets of a session.
 #[derive(Clone, Encode, Decode, RuntimeDebug, TypeInfo)]
-#[cfg_attr(feature = "std", derive(PartialEq, MallocSizeOf, Default))]
-#[cfg_attr(all(feature = "std", test), derive(Default))]
+#[cfg_attr(feature = "std", derive(PartialEq, MallocSizeOf))]
 pub struct SessionInfo {
 	/****** New in v2 *******/
 	/// All the validators actively participating in parachain consensus.

From cac69c609c5dccb6601c449437ebb791196d800d Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 16:15:58 +0000
Subject: [PATCH 17/21] add dummy_session_info helper

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 Cargo.lock                               |  1 +
 node/network/gossip-support/Cargo.toml   |  1 +
 node/network/gossip-support/src/tests.rs | 23 ++++-------------------
 primitives/test-helpers/src/lib.rs       | 21 +++++++++++++++++++++
 4 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 86e93fda792c..3b8cb761317e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6167,6 +6167,7 @@ dependencies = [
  "polkadot-node-subsystem-test-helpers",
  "polkadot-node-subsystem-util",
  "polkadot-primitives",
+ "polkadot-primitives-test-helpers",
  "rand 0.8.4",
  "rand_chacha 0.3.1",
  "sc-network",
diff --git a/node/network/gossip-support/Cargo.toml b/node/network/gossip-support/Cargo.toml
index e9f41edca58b..3179a29ae15e 100644
--- a/node/network/gossip-support/Cargo.toml
+++ b/node/network/gossip-support/Cargo.toml
@@ -31,3 +31,4 @@ polkadot-node-subsystem-test-helpers = { path = "../../subsystem-test-helpers" }
 assert_matches = "1.4.0"
 async-trait = "0.1.52"
 lazy_static = "1.4.0"
+polkadot-primitives-test-helpers =  { path = "../../../primitives/test-helpers" }
\ No newline at end of file
diff --git a/node/network/gossip-support/src/tests.rs b/node/network/gossip-support/src/tests.rs
index b34fa2106e20..d97c8edf3ad9 100644
--- a/node/network/gossip-support/src/tests.rs
+++ b/node/network/gossip-support/src/tests.rs
@@ -34,6 +34,7 @@ use polkadot_node_subsystem::{
 };
 use polkadot_node_subsystem_test_helpers as test_helpers;
 use polkadot_node_subsystem_util::TimeoutExt as _;
+use polkadot_primitives_test_helpers::dummy_session_info;
 use test_helpers::mock::make_ferdie_keystore;
 
 use super::*;
@@ -58,22 +59,6 @@ lazy_static! {
 		Sr25519Keyring::Charlie.public().into(),
 		Sr25519Keyring::Eve.public().into(),
 	];
-	static ref SESSION_INFO: polkadot_primitives::v2::SessionInfo =
-		polkadot_primitives::v2::SessionInfo {
-			active_validator_indices: Vec::new(),
-			random_seed: [0u8; 32],
-			dispute_period: 10,
-			validators: Vec::new(),
-			discovery_keys: Vec::new(),
-			assignment_keys: Vec::new(),
-			validator_groups: Vec::new(),
-			n_cores: 1,
-			zeroth_delay_tranche_width: 0,
-			relay_vrf_modulo_samples: 0,
-			n_delay_tranches: 0,
-			no_show_slots: 0,
-			needed_approvals: 0,
-		};
 }
 
 type VirtualOverseer = test_helpers::TestSubsystemContextHandle<GossipSupportMessage>;
@@ -282,7 +267,7 @@ fn issues_a_connection_request_on_new_session() {
 				RuntimeApiRequest::SessionInfo(1, sender),
 			)) => {
 				assert_eq!(relay_parent, hash);
-				sender.send(Ok(Some(SESSION_INFO.clone()))).unwrap();
+				sender.send(Ok(Some(dummy_session_info()))).unwrap();
 			}
 		);
 
@@ -360,7 +345,7 @@ fn issues_a_connection_request_on_new_session() {
 				RuntimeApiRequest::SessionInfo(2, sender),
 			)) => {
 				assert_eq!(relay_parent, hash);
-				sender.send(Ok(Some(SESSION_INFO.clone()))).unwrap();
+				sender.send(Ok(Some(dummy_session_info()))).unwrap();
 			}
 		);
 
@@ -458,7 +443,7 @@ fn issues_a_connection_request_when_last_request_was_mostly_unresolved() {
 					RuntimeApiRequest::SessionInfo(1, sender),
 				)) => {
 					assert_eq!(relay_parent, hash);
-					sender.send(Ok(Some(SESSION_INFO.clone()))).unwrap();
+					sender.send(Ok(Some(dummy_session_info()))).unwrap();
 				}
 			);
 
diff --git a/primitives/test-helpers/src/lib.rs b/primitives/test-helpers/src/lib.rs
index ccf103d79e58..a60505c36948 100644
--- a/primitives/test-helpers/src/lib.rs
+++ b/primitives/test-helpers/src/lib.rs
@@ -26,6 +26,9 @@ use polkadot_primitives::v1::{
 	CommittedCandidateReceipt, Hash, HeadData, Id as ParaId, ValidationCode, ValidationCodeHash,
 	ValidatorId,
 };
+
+use polkadot_primitives::v2::SessionInfo;
+
 use sp_application_crypto::sr25519;
 use sp_keyring::Sr25519Keyring;
 use sp_runtime::generic::Digest;
@@ -224,3 +227,21 @@ impl TestCandidateBuilder {
 		CandidateReceipt { descriptor, commitments_hash: self.commitments_hash }
 	}
 }
+
+pub fn dummy_session_info() -> SessionInfo {
+	SessionInfo {
+		active_validator_indices: Vec::new(),
+		random_seed: [0u8; 32],
+		dispute_period: 10,
+		validators: Vec::new(),
+		discovery_keys: Vec::new(),
+		assignment_keys: Vec::new(),
+		validator_groups: Vec::new(),
+		n_cores: 0,
+		zeroth_delay_tranche_width: 0,
+		relay_vrf_modulo_samples: 0,
+		n_delay_tranches: 0,
+		no_show_slots: 0,
+		needed_approvals: 0,
+	}
+}

From a0930ec51be04ddd14885de1d023414004fe2808 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 16:35:45 +0000
Subject: [PATCH 18/21] unset parachain validator status if no longer authority

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 node/network/gossip-support/src/lib.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/node/network/gossip-support/src/lib.rs b/node/network/gossip-support/src/lib.rs
index e035353f8f82..a12fbf82d236 100644
--- a/node/network/gossip-support/src/lib.rs
+++ b/node/network/gossip-support/src/lib.rs
@@ -268,6 +268,7 @@ where
 				},
 				Err(util::Error::NotAValidator) => {
 					self.metrics.on_is_not_authority();
+					self.metrics.on_is_not_parachain_validator();
 					None
 				},
 				// Don't update on runtime errors.

From c953489d216efaf037dda042c5660de8d4cd7f2c Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 16:39:57 +0000
Subject: [PATCH 19/21] update

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 Cargo.lock                               |  1 -
 node/network/gossip-support/Cargo.toml   |  1 -
 node/network/gossip-support/src/tests.rs |  7 +++----
 primitives/test-helpers/src/lib.rs       | 18 ------------------
 4 files changed, 3 insertions(+), 24 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 3b8cb761317e..86e93fda792c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -6167,7 +6167,6 @@ dependencies = [
  "polkadot-node-subsystem-test-helpers",
  "polkadot-node-subsystem-util",
  "polkadot-primitives",
- "polkadot-primitives-test-helpers",
  "rand 0.8.4",
  "rand_chacha 0.3.1",
  "sc-network",
diff --git a/node/network/gossip-support/Cargo.toml b/node/network/gossip-support/Cargo.toml
index 3179a29ae15e..e9f41edca58b 100644
--- a/node/network/gossip-support/Cargo.toml
+++ b/node/network/gossip-support/Cargo.toml
@@ -31,4 +31,3 @@ polkadot-node-subsystem-test-helpers = { path = "../../subsystem-test-helpers" }
 assert_matches = "1.4.0"
 async-trait = "0.1.52"
 lazy_static = "1.4.0"
-polkadot-primitives-test-helpers =  { path = "../../../primitives/test-helpers" }
\ No newline at end of file
diff --git a/node/network/gossip-support/src/tests.rs b/node/network/gossip-support/src/tests.rs
index d97c8edf3ad9..5009742e8631 100644
--- a/node/network/gossip-support/src/tests.rs
+++ b/node/network/gossip-support/src/tests.rs
@@ -34,7 +34,6 @@ use polkadot_node_subsystem::{
 };
 use polkadot_node_subsystem_test_helpers as test_helpers;
 use polkadot_node_subsystem_util::TimeoutExt as _;
-use polkadot_primitives_test_helpers::dummy_session_info;
 use test_helpers::mock::make_ferdie_keystore;
 
 use super::*;
@@ -267,7 +266,7 @@ fn issues_a_connection_request_on_new_session() {
 				RuntimeApiRequest::SessionInfo(1, sender),
 			)) => {
 				assert_eq!(relay_parent, hash);
-				sender.send(Ok(Some(dummy_session_info()))).unwrap();
+				sender.send(Ok(None)).unwrap();
 			}
 		);
 
@@ -345,7 +344,7 @@ fn issues_a_connection_request_on_new_session() {
 				RuntimeApiRequest::SessionInfo(2, sender),
 			)) => {
 				assert_eq!(relay_parent, hash);
-				sender.send(Ok(Some(dummy_session_info()))).unwrap();
+				sender.send(Ok(None)).unwrap();
 			}
 		);
 
@@ -443,7 +442,7 @@ fn issues_a_connection_request_when_last_request_was_mostly_unresolved() {
 					RuntimeApiRequest::SessionInfo(1, sender),
 				)) => {
 					assert_eq!(relay_parent, hash);
-					sender.send(Ok(Some(dummy_session_info()))).unwrap();
+					sender.send(Ok(None)).unwrap();
 				}
 			);
 
diff --git a/primitives/test-helpers/src/lib.rs b/primitives/test-helpers/src/lib.rs
index a60505c36948..f0bf6112ca9a 100644
--- a/primitives/test-helpers/src/lib.rs
+++ b/primitives/test-helpers/src/lib.rs
@@ -227,21 +227,3 @@ impl TestCandidateBuilder {
 		CandidateReceipt { descriptor, commitments_hash: self.commitments_hash }
 	}
 }
-
-pub fn dummy_session_info() -> SessionInfo {
-	SessionInfo {
-		active_validator_indices: Vec::new(),
-		random_seed: [0u8; 32],
-		dispute_period: 10,
-		validators: Vec::new(),
-		discovery_keys: Vec::new(),
-		assignment_keys: Vec::new(),
-		validator_groups: Vec::new(),
-		n_cores: 0,
-		zeroth_delay_tranche_width: 0,
-		relay_vrf_modulo_samples: 0,
-		n_delay_tranches: 0,
-		no_show_slots: 0,
-		needed_approvals: 0,
-	}
-}

From 4633e8c0564bed210cc5960227718af85a5a7bca Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 16:41:52 +0000
Subject: [PATCH 20/21] damn

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 primitives/test-helpers/src/lib.rs | 2 --
 1 file changed, 2 deletions(-)

diff --git a/primitives/test-helpers/src/lib.rs b/primitives/test-helpers/src/lib.rs
index f0bf6112ca9a..09da521b6219 100644
--- a/primitives/test-helpers/src/lib.rs
+++ b/primitives/test-helpers/src/lib.rs
@@ -27,8 +27,6 @@ use polkadot_primitives::v1::{
 	ValidatorId,
 };
 
-use polkadot_primitives::v2::SessionInfo;
-
 use sp_application_crypto::sr25519;
 use sp_keyring::Sr25519Keyring;
 use sp_runtime::generic::Digest;

From 541ad6da73d87d31c1ef89fa0814a05afbc49ac6 Mon Sep 17 00:00:00 2001
From: Andrei Sandu <andrei-mihail@parity.io>
Date: Thu, 13 Jan 2022 16:42:28 +0000
Subject: [PATCH 21/21] :facepalm:

Signed-off-by: Andrei Sandu <andrei-mihail@parity.io>
---
 primitives/test-helpers/src/lib.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/primitives/test-helpers/src/lib.rs b/primitives/test-helpers/src/lib.rs
index 09da521b6219..ccf103d79e58 100644
--- a/primitives/test-helpers/src/lib.rs
+++ b/primitives/test-helpers/src/lib.rs
@@ -26,7 +26,6 @@ use polkadot_primitives::v1::{
 	CommittedCandidateReceipt, Hash, HeadData, Id as ParaId, ValidationCode, ValidationCodeHash,
 	ValidatorId,
 };
-
 use sp_application_crypto::sr25519;
 use sp_keyring::Sr25519Keyring;
 use sp_runtime::generic::Digest;