From a4c4f24b93e2b41ee32e800490a14a5794498955 Mon Sep 17 00:00:00 2001
From: Jan Ciolek <jan@near.org>
Date: Tue, 13 Feb 2024 13:54:45 +0000
Subject: [PATCH] Remove witness retrying logic on missing block

Sometimes when we would like to process a ChunkStateWitness the
block required to process it isn't available yet, we have to wait
for it. https://github.com/near/nearcore/pull/10535 implemented a
hacky way to do it by retrying the processing every 500ms until the
required block arrives. This PR will implement a proper solution, so
let's remove the hacky workaround.
---
 chain/client/src/adapter.rs                   |  6 +----
 chain/client/src/client_actor.rs              | 27 +++----------------
 .../stateless_validation/chunk_validator.rs   | 13 +++------
 3 files changed, 8 insertions(+), 38 deletions(-)

diff --git a/chain/client/src/adapter.rs b/chain/client/src/adapter.rs
index ad1254c1290..40f1d6eb102 100644
--- a/chain/client/src/adapter.rs
+++ b/chain/client/src/adapter.rs
@@ -141,7 +141,6 @@ pub enum ProcessTxResponse {
 pub struct ChunkStateWitnessMessage {
     pub witness: ChunkStateWitness,
     pub peer_id: PeerId,
-    pub attempts_remaining: usize,
 }
 
 #[derive(actix::Message, Debug)]
@@ -350,10 +349,7 @@ impl near_network::client::Client for Adapter {
     async fn chunk_state_witness(&self, witness: ChunkStateWitness, peer_id: PeerId) {
         match self
             .client_addr
-            .send(
-                ChunkStateWitnessMessage { witness, peer_id, attempts_remaining: 5 }
-                    .with_span_context(),
-            )
+            .send(ChunkStateWitnessMessage { witness, peer_id }.with_span_context())
             .await
         {
             Ok(()) => {}
diff --git a/chain/client/src/client_actor.rs b/chain/client/src/client_actor.rs
index 684e60a076e..40503b2dead 100644
--- a/chain/client/src/client_actor.rs
+++ b/chain/client/src/client_actor.rs
@@ -2006,32 +2006,11 @@ impl Handler<WithSpanContext<ChunkStateWitnessMessage>> for ClientActor {
     fn handle(
         &mut self,
         msg: WithSpanContext<ChunkStateWitnessMessage>,
-        ctx: &mut Context<Self>,
+        _ctx: &mut Context<Self>,
     ) -> Self::Result {
         let (_span, msg) = handler_debug_span!(target: "client", msg);
-        let peer_id = msg.peer_id.clone();
-        let attempts_remaining = msg.attempts_remaining;
-        match self.client.process_chunk_state_witness(msg.witness, msg.peer_id, None) {
-            Err(err) => {
-                tracing::error!(target: "client", ?err, "Error processing chunk state witness");
-            }
-            Ok(Some(witness)) => {
-                if attempts_remaining > 0 {
-                    ctx.run_later(Duration::from_millis(100), move |_, ctx| {
-                        ctx.address().do_send(
-                            ChunkStateWitnessMessage {
-                                witness,
-                                peer_id,
-                                attempts_remaining: attempts_remaining - 1,
-                            }
-                            .with_span_context(),
-                        );
-                    });
-                } else {
-                    tracing::error!(target: "client", "Failed to process chunk state witness even after 5 tries due to missing parent block");
-                }
-            }
-            Ok(None) => {}
+        if let Err(err) = self.client.process_chunk_state_witness(msg.witness, msg.peer_id, None) {
+            tracing::error!(target: "client", ?err, "Error processing chunk state witness");
         }
     }
 }
diff --git a/chain/client/src/stateless_validation/chunk_validator.rs b/chain/client/src/stateless_validation/chunk_validator.rs
index 46b184558f0..21e6ffb2351 100644
--- a/chain/client/src/stateless_validation/chunk_validator.rs
+++ b/chain/client/src/stateless_validation/chunk_validator.rs
@@ -588,18 +588,13 @@ impl Client {
         witness: ChunkStateWitness,
         peer_id: PeerId,
         processing_done_tracker: Option<ProcessingDoneTracker>,
-    ) -> Result<Option<ChunkStateWitness>, Error> {
+    ) -> Result<(), Error> {
         // TODO(#10502): Handle production of state witness for first chunk after genesis.
         // Properly handle case for chunk right after genesis.
         // Context: We are currently unable to handle production of the state witness for the
         // first chunk after genesis as it's not possible to run the genesis chunk in runtime.
         let prev_block_hash = witness.inner.chunk_header.prev_block_hash();
-        let prev_block = match self.chain.get_block(prev_block_hash) {
-            Ok(block) => block,
-            Err(_) => {
-                return Ok(Some(witness));
-            }
-        };
+        let prev_block = self.chain.get_block(prev_block_hash)?;
         let prev_chunk_header = Chain::get_prev_chunk_header(
             self.epoch_manager.as_ref(),
             &prev_block,
@@ -616,7 +611,7 @@ impl Client {
                 &self.chunk_validator.network_sender,
                 self.chunk_endorsement_tracker.as_ref(),
             );
-            return Ok(None);
+            return Ok(());
         }
 
         // TODO(#10265): If the previous block does not exist, we should
@@ -635,6 +630,6 @@ impl Client {
                 },
             ));
         }
-        result.map(|_| None)
+        result
     }
 }