From f77b8139c0a59d9fafc030df02f86fd6e8864377 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bastian=20K=C3=B6cher?= <bkchr@users.noreply.github.com>
Date: Sat, 4 Jul 2020 02:10:47 +0200
Subject: [PATCH] Make a collator send a collation as backup as well (#1353)
Currently a collator will only send a collation to validators it is a
primary for. While testing this could lead to the situation that the
same collator was registered as prime for all Parachain validators but
failed for other reasons to generate a PoVBlock. However no other
collator was sending a collation, which stopped the Parachain until the
faulty collator was stopped.
This pr solves this problem by making sure that every collator sends a
collation to one of his validators he is connected to, but registered as backup.
---
polkadot/Cargo.lock | 1 +
polkadot/network/Cargo.toml | 1 +
.../network/src/legacy/local_collations.rs | 18 +++++++++++++-----
3 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/polkadot/Cargo.lock b/polkadot/Cargo.lock
index 22c14cc8b38..61f29625afc 100644
--- a/polkadot/Cargo.lock
+++ b/polkadot/Cargo.lock
@@ -4358,6 +4358,7 @@ dependencies = [
"polkadot-erasure-coding",
"polkadot-primitives",
"polkadot-validation",
+ "rand 0.7.3",
"sc-network",
"sc-network-gossip",
"sp-api",
diff --git a/polkadot/network/Cargo.toml b/polkadot/network/Cargo.toml
index 804cdcb3f11..bfee6f34550 100644
--- a/polkadot/network/Cargo.toml
+++ b/polkadot/network/Cargo.toml
@@ -26,6 +26,7 @@ futures-timer = "2.0"
sp-blockchain = { git = "https://github.com/paritytech/substrate", branch = "master" }
sp-api = { git = "https://github.com/paritytech/substrate", branch = "master" }
wasm-timer = "0.2.4"
+rand = "0.7.3"
[dev-dependencies]
sp-keyring = { git = "https://github.com/paritytech/substrate", branch = "master" }
diff --git a/polkadot/network/src/legacy/local_collations.rs b/polkadot/network/src/legacy/local_collations.rs
index f1a6615e88b..6bc9b985a7c 100644
--- a/polkadot/network/src/legacy/local_collations.rs
+++ b/polkadot/network/src/legacy/local_collations.rs
@@ -24,6 +24,7 @@ use crate::legacy::collator_pool::Role;
use std::collections::{HashMap, HashSet};
use std::time::Duration;
use wasm_timer::Instant;
+use rand::seq::SliceRandom;
const LIVE_FOR: Duration = Duration::from_secs(60 * 5);
@@ -106,9 +107,7 @@ impl<C: Clone> LocalCollations<C> {
relay_parent: Hash,
targets: HashSet<ValidatorId>,
collation: C
- )
- -> impl Iterator<Item=(ValidatorId, C)> + 'a
- {
+ ) -> impl Iterator<Item=(ValidatorId, C)> + 'a {
self.local_collations.insert(relay_parent, LocalCollation {
targets,
collation,
@@ -119,8 +118,17 @@ impl<C: Clone> LocalCollations<C> {
.expect("just inserted to this key; qed");
let borrowed_collation = &local.collation;
+
+ // If we are conected to multiple validators,
+ // make sure we always send the collation to one of the validators
+ // we are registered as backup. This ensures that one collator that
+ // is primary at multiple validators, desn't block the Parachain from progressing.
+ let mut rng = rand::thread_rng();
+ let diff = local.targets.difference(&self.primary_for).collect::<Vec<_>>();
+
local.targets
.intersection(&self.primary_for)
+ .chain(diff.choose(&mut rng).map(|r| r.clone()))
.map(move |k| (k.clone(), borrowed_collation.clone()))
}
@@ -149,7 +157,7 @@ mod tests {
};
let mut tracker = LocalCollations::new();
- assert!(tracker.add_collation(relay_parent, targets, 5).next().is_none());
+ assert!(tracker.add_collation(relay_parent, targets, 5).next().is_some());
assert_eq!(tracker.note_validator_role(key, Role::Primary), vec![(relay_parent, 5)]);
}
@@ -165,7 +173,7 @@ mod tests {
};
let mut tracker: LocalCollations<u8> = LocalCollations::new();
- assert!(tracker.add_collation(relay_parent, targets, 5).next().is_none());
+ assert!(tracker.add_collation(relay_parent, targets, 5).next().is_some());
assert!(tracker.note_validator_role(orig_key.clone(), Role::Primary).is_empty());
assert_eq!(tracker.fresh_key(&orig_key, &new_key), vec![(relay_parent, 5u8)]);
}
--
GitLab