feat: relocation during startup no-longer required

src/relocation.rs

@@ -15,19 +15,13 @@ use crate::{
     network::Network,
     peer::Peer,
     section::{MemberInfo, Section},
-    MIN_AGE,
 };
 use bytes::Bytes;
-use rand::{Rng, SeedableRng};
-use rand_chacha::ChaCha8Rng;
 use serde::{de::Error as SerdeDeError, Deserialize, Deserializer, Serialize, Serializer};
-use std::{convert::TryInto, net::SocketAddr, ops::Range};
+use std::net::SocketAddr;
 use tokio::sync::mpsc;
 use xor_name::XorName;
 
-// Range from which the age of a joining node is selected during the startup phase.
-pub(crate) const STARTUP_PHASE_AGE_RANGE: Range<u8> = (MIN_AGE + 1)..32;
-
 /// Find all nodes to relocate after a churn event and create the relocate actions for them.
 pub(crate) fn actions(
     section: &Section,
@@ -268,16 +262,6 @@ pub(crate) fn check(age: u8, churn_signature: &bls::Signature) -> bool {
     trailing_zeros(&churn_signature.to_bytes()[..]) >= age as u32
 }
 
-// Generate age for relocated peer during the starup phase, using the `Online` vote signature as
-// the random seed.
-pub(crate) fn startup_phase_age(signature: &bls::Signature) -> u8 {
-    let seed = signature.to_bytes()[..32]
-        .try_into()
-        .expect("invalid signature length");
-    let mut rng = ChaCha8Rng::from_seed(seed);
-    rng.gen_range(STARTUP_PHASE_AGE_RANGE.start, STARTUP_PHASE_AGE_RANGE.end)
-}
-
 // Compute the destination for the node with `relocating_name` to be relocated to. `churn_name` is
 // the name of the joined/left node that triggered the relocation.
 fn destination(relocating_name: &XorName, churn_name: &XorName) -> XorName {
@@ -316,13 +300,13 @@ mod tests {
     use super::*;
     use crate::{
         consensus::test_utils::proven, peer::test_utils::arbitrary_unique_peers,
-        section::EldersInfo, SectionProofChain, ELDER_SIZE,
+        section::EldersInfo, SectionProofChain, ELDER_SIZE, MIN_AGE,
     };
     use anyhow::Result;
     use assert_matches::assert_matches;
     use itertools::Itertools;
     use proptest::prelude::*;
-    use rand::rngs::SmallRng;
+    use rand::{rngs::SmallRng, Rng, SeedableRng};
     use xor_name::Prefix;
 
     #[test]

src/routing/approved.rs

@@ -1130,25 +1130,6 @@ impl Approved {
         Ok(commands)
     }
 
-    fn relocate_peer_in_startup_phase(
-        &self,
-        peer: Peer,
-        signature: &bls::Signature,
-    ) -> Result<Vec<Command>> {
-        let age = relocation::startup_phase_age(signature);
-        let details =
-            RelocateDetails::with_age(&self.section, &self.network, &peer, *peer.name(), age);
-
-        trace!(
-            "Relocating {:?} to {} with age {} in startup phase",
-            peer,
-            details.destination,
-            details.age
-        );
-
-        self.send_relocate(&peer, details)
-    }
-
     fn relocate_rejoining_peer(&self, peer: Peer, age: u8) -> Result<Vec<Command>> {
         let details =
             RelocateDetails::with_age(&self.section, &self.network, &peer, *peer.name(), age);
@@ -1195,9 +1176,8 @@ impl Approved {
                 );
                 return Ok(commands);
             }
-            // To avoid during startup_phase, a rejoin node being given a randmly higher age,
-            // force it to be halved.
-            if is_startup_phase || info.peer.age() / 2 > MIN_AGE {
+
+            if info.peer.age() / 2 > MIN_AGE {
                 // TODO: consider handling the relocation inside the bootstrap phase, to avoid having
                 // to send this `NodeApproval`.
                 commands.push(self.send_node_approval(&peer, their_knowledge)?);
@@ -1208,45 +1188,28 @@ impl Approved {
             }
         }
 
-        if is_startup_phase && peer.age() <= MIN_AGE {
-            // In startup phase, instantly relocate the joining peer in order to promote it to
-            // adult.
-
-            if self.section.members().is_known(peer.name()) {
-                info!("ignore Online: {:?}", peer);
-                return Ok(vec![]);
-            }
-
-            // TODO: consider handling the relocation inside the bootstrap phase, to avoid having
-            // to send this `NodeApproval`.
-            commands.push(self.send_node_approval(&peer, their_knowledge)?);
-            commands.extend(self.relocate_peer_in_startup_phase(peer, &signature)?);
-        } else {
-            // Post startup phase, add the new peer normally.
-
-            if !self.section.update_member(Proven {
-                value: member_info,
-                proof,
-            }) {
-                info!("ignore Online: {:?}", peer);
-                return Ok(vec![]);
-            }
+        if !self.section.update_member(Proven {
+            value: member_info,
+            proof,
+        }) {
+            info!("ignore Online: {:?}", peer);
+            return Ok(vec![]);
+        }
 
-            info!("handle Online: {:?}", peer);
+        info!("handle Online: {:?}", peer);
 
-            commands.push(self.send_node_approval(&peer, their_knowledge)?);
-            commands.extend(self.relocate_peers(peer.name(), &signature)?);
-            commands.extend(self.promote_and_demote_elders()?);
+        commands.push(self.send_node_approval(&peer, their_knowledge)?);
+        commands.extend(self.relocate_peers(peer.name(), &signature)?);
+        commands.extend(self.promote_and_demote_elders()?);
 
-            self.send_event(Event::MemberJoined {
-                name: *peer.name(),
-                previous_name,
-                age: peer.age(),
-                startup_relocation: is_startup_phase,
-            });
+        self.send_event(Event::MemberJoined {
+            name: *peer.name(),
+            previous_name,
+            age: peer.age(),
+            startup_relocation: is_startup_phase,
+        });
 
-            self.print_network_stats();
-        }
+        self.print_network_stats();
 
         Ok(commands)
     }

src/routing/mod.rs

@@ -33,9 +33,8 @@ use crate::{
     messages::{Message, PING},
     node::Node,
     peer::Peer,
-    relocation::STARTUP_PHASE_AGE_RANGE,
     section::{EldersInfo, SectionProofChain},
-    TransportConfig,
+    TransportConfig, MIN_AGE,
 };
 use bytes::Bytes;
 use ed25519_dalek::{Keypair, PublicKey, Signature, Signer};
@@ -96,8 +95,7 @@ impl Routing {
         let (state, comm, backlog) = if config.first {
             info!("{} Starting a new network as the seed node.", node_name);
             let comm = Comm::new(config.transport_config, connection_event_tx)?;
-            let node = Node::new(keypair, comm.our_connection_info().await?)
-                .with_age(STARTUP_PHASE_AGE_RANGE.end);
+            let node = Node::new(keypair, comm.our_connection_info().await?).with_age(MIN_AGE + 1);
             let state = Approved::first_node(node, event_tx)?;
 
             state.send_event(Event::PromotedToElder);

src/section/section_peers.rs

@@ -92,11 +92,6 @@ impl SectionPeers {
             .unwrap_or(false)
     }
 
-    /// Returns whether the given peer is known to us (joined or left)
-    pub fn is_known(&self, name: &XorName) -> bool {
-        self.members.contains_key(name)
-    }
-
     /// Update a member of our section.
     /// Returns whether anything actually changed.
     pub fn update(&mut self, new_info: Proven<MemberInfo>) -> bool {

tests/bootstrap.rs

@@ -97,9 +97,7 @@ async fn test_startup_section_bootstrapping() -> Result<()> {
             let (node, mut event_stream) =
                 create_node(config_with_contact(genesis_contact)).await?;
 
-            // During the startup phase, joining nodes are instantly relocated.
-            assert_next_event!(event_stream, Event::RelocationStarted { .. });
-            assert_next_event!(event_stream, Event::Relocated { .. });
+            assert_event!(event_stream, Event::PromotedToElder);
 
             Ok::<_, Error>(node)
         })