From 40d9941c2663709ace4c8e048bfd5ad5bcb60473 Mon Sep 17 00:00:00 2001
From: Nazar Mokrynskyi <nazar@mokrynskyi.com>
Date: Fri, 29 Apr 2022 00:20:57 +0300
Subject: [PATCH] Faster segment acknowledgement on the farmer

---
 crates/sc-consensus-subspace-rpc/src/lib.rs |  4 +++-
 crates/subspace-farmer/src/archiving.rs     | 10 +++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/crates/sc-consensus-subspace-rpc/src/lib.rs b/crates/sc-consensus-subspace-rpc/src/lib.rs
index 1b78b953c67dd..7af10b34b490b 100644
--- a/crates/sc-consensus-subspace-rpc/src/lib.rs
+++ b/crates/sc-consensus-subspace-rpc/src/lib.rs
@@ -557,7 +557,9 @@ where
 
             if let Some(mut sender) = maybe_sender {
                 if let Err(error) = sender.send(()).await {
-                    warn!("Failed to acknowledge archived segment: {error}");
+                    if !error.is_disconnected() {
+                        warn!("Failed to acknowledge archived segment: {error}");
+                    }
                 }
             }
 
diff --git a/crates/subspace-farmer/src/archiving.rs b/crates/subspace-farmer/src/archiving.rs
index a3569dfc12b5c..85a3c98ddcaeb 100644
--- a/crates/subspace-farmer/src/archiving.rs
+++ b/crates/subspace-farmer/src/archiving.rs
@@ -171,13 +171,17 @@ impl Archiving {
                             Some(archived_segment) => {
                                 let segment_index = archived_segment.root_block.segment_index();
                                 let (acknowledge_sender, acknowledge_receiver) = oneshot::channel();
+                                // Acknowledge immediately to allow node to continue sync quickly,
+                                // but this will miss some segments in case farmer crashed in the
+                                // meantime. Ideally we'd acknowledge after, but it makes node wait
+                                // for it and the whole process very sequential.
+                                if let Err(error) = client.acknowledge_archived_segment(segment_index).await {
+                                    error!("Failed to send archived segment acknowledgement: {error}");
+                                }
                                 if let Err(error) = archived_segments_sync_sender.send((archived_segment, acknowledge_sender)) {
                                     error!("Failed to send archived segment for plotting: {error}");
                                 }
                                 let _ = acknowledge_receiver.await;
-                                if let Err(error) = client.acknowledge_archived_segment(segment_index).await {
-                                    error!("Failed to send archived segment acknowledgement: {error}");
-                                }
                             },
                             None => {
                                 debug!("Subscription has forcefully closed from node side!");