fix: wait couple rounds for no pings to send an event (#3315)

Description
---
Wait couple rounds of `no ping` before sending the event.

How Has This Been Tested?
---
npm test -- --name "Full block sync with small reorg"
npm test -- --name "Pruned mode reorg simple"
npm test -- --name "Pruned mode reorg past horizon"

base_layer/core/src/base_node/chain_metadata_service/handle.rs

@@ -53,6 +53,7 @@ impl Display for PeerChainMetadata {
 #[derive(Debug)]
 pub enum ChainMetadataEvent {
     PeerChainMetadataReceived(Vec<PeerChainMetadata>),
+    NetworkSilence,
 }
 
 #[derive(Clone)]

base_layer/core/src/base_node/chain_metadata_service/service.rs

@@ -43,12 +43,15 @@ use tari_comms::{
 use tari_p2p::services::liveness::{LivenessEvent, LivenessHandle, Metadata, MetadataKey};
 use tokio::sync::broadcast;
 
+const NUM_ROUNDS_NETWORK_SILENCE: u16 = 3;
+
 pub(super) struct ChainMetadataService {
     liveness: LivenessHandle,
     base_node: LocalNodeCommsInterface,
     peer_chain_metadata: Vec<PeerChainMetadata>,
     connectivity: ConnectivityRequester,
     event_publisher: broadcast::Sender<Arc<ChainMetadataEvent>>,
+    number_of_rounds_no_pings: u16,
 }
 
 impl ChainMetadataService {
@@ -69,6 +72,7 @@ impl ChainMetadataService {
             peer_chain_metadata: Vec::new(),
             connectivity,
             event_publisher,
+            number_of_rounds_no_pings: 0,
         }
     }
 
@@ -159,6 +163,7 @@ impl ChainMetadataService {
                     "Received ping from neighbouring node '{}'.",
                     event.node_id
                 );
+                self.number_of_rounds_no_pings = 0;
                 self.collect_chain_state_from_ping(&event.node_id, &event.metadata)?;
                 self.send_chain_metadata_to_event_publisher().await?;
             },
@@ -169,6 +174,7 @@ impl ChainMetadataService {
                     "Received pong from neighbouring node '{}'.",
                     event.node_id
                 );
+                self.number_of_rounds_no_pings = 0;
                 self.collect_chain_state_from_pong(&event.node_id, &event.metadata)?;
                 self.send_chain_metadata_to_event_publisher().await?;
             },
@@ -178,7 +184,14 @@ impl ChainMetadataService {
                     target: LOG_TARGET,
                     "New chain metadata round sent to {} peer(s)", num_peers
                 );
-                self.send_chain_metadata_to_event_publisher().await?;
+                // If there were no pings for awhile, we are probably alone.
+                if *num_peers == 0 {
+                    self.number_of_rounds_no_pings += 1;
+                    if self.number_of_rounds_no_pings >= NUM_ROUNDS_NETWORK_SILENCE {
+                        self.send_network_silence().await?;
+                        self.number_of_rounds_no_pings = 0;
+                    }
+                }
                 // Ensure that we're waiting for the correct amount of peers to respond
                 // and have allocated space for their replies
 
@@ -189,6 +202,11 @@ impl ChainMetadataService {
         Ok(())
     }
 
+    async fn send_network_silence(&mut self) -> Result<(), ChainMetadataSyncError> {
+        let _ = self.event_publisher.send(Arc::new(ChainMetadataEvent::NetworkSilence));
+        Ok(())
+    }
+
     async fn send_chain_metadata_to_event_publisher(&mut self) -> Result<(), ChainMetadataSyncError> {
         // send only fails if there are no subscribers.
         let _ = self

base_layer/core/src/base_node/state_machine_service/states/listening.rs

@@ -120,6 +120,14 @@ impl Listening {
         loop {
             let metadata_event = shared.metadata_event_stream.recv().await;
             match metadata_event.as_ref().map(|v| v.deref()) {
+                Ok(ChainMetadataEvent::NetworkSilence) => {
+                    debug!("NetworkSilence event received");
+                    if !self.is_synced {
+                        self.is_synced = true;
+                        shared.set_state_info(StateInfo::Listening(ListeningInfo::new(true)));
+                        debug!(target: LOG_TARGET, "Initial sync achieved");
+                    }
+                },
                 Ok(ChainMetadataEvent::PeerChainMetadataReceived(peer_metadata_list)) => {
                     let mut peer_metadata_list = peer_metadata_list.clone();
 

integration_tests/features/Reorgs.feature

@@ -39,7 +39,7 @@ Feature: Reorgs
     And I mine a block on B at height 4 with an invalid MMR
     Then node B is at tip BTip1
 
-  @critical @reorg @broken
+  @critical @reorg
   Scenario: Pruned mode reorg simple
     Given I have a base node NODE1 connected to all seed nodes
     And I have wallet WALLET1 connected to base node NODE1
@@ -63,7 +63,7 @@ Feature: Reorgs
     When I start base node NODE1
     Then all nodes are at height 20
 
-  @critical @reorg @broken
+  @critical @reorg
   Scenario: Pruned mode reorg past horizon
     Given I have a base node NODE1 connected to all seed nodes
     And I have wallet WALLET1 connected to base node NODE1

integration_tests/features/Sync.feature

@@ -45,7 +45,7 @@ Feature: Block Sync
     Then NODE1 should have 11 peers
     Then NODE2 should have 11 peers
 
-  @critical @reorg @broken
+  @critical @reorg
   Scenario: Full block sync with small reorg
     Given I have a base node NODE1
     And I have wallet WALLET1 connected to base node NODE1