fix(hermes): reconnect on wh connection termination (#1488)

* fix(hermes): reconnect on wh connection termination

`tokio::select` disables the branch that runs the wh connection
if it returns OK and it never gets checked again. This change
changes the `run` return to never return OK.

* refactor(hermes): use Result<!> in pythnet network listener thread

Author: ali-behjati

apps/hermes/Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name        = "hermes"
-version     = "0.5.5"
+version     = "0.5.6"
 description = "Hermes is an agent that provides Verified Prices from the Pythnet Pyth Oracle."
 edition     = "2021"
 

apps/hermes/Cargo.toml

@@ -139,7 +139,7 @@ async fn fetch_bridge_data(
     }
 }
 
-pub async fn run(store: Arc<State>, pythnet_ws_endpoint: String) -> Result<()> {
+pub async fn run(store: Arc<State>, pythnet_ws_endpoint: String) -> Result<!> {
     let client = PubsubClient::new(pythnet_ws_endpoint.as_ref()).await?;
 
     let config = RpcProgramAccountsConfig {
@@ -160,59 +160,54 @@ pub async fn run(store: Arc<State>, pythnet_ws_endpoint: String) -> Result<()> {
         .program_subscribe(&system_program::id(), Some(config))
         .await?;
 
-    loop {
-        match notif.next().await {
-            Some(update) => {
-                let account: Account = match update.value.account.decode() {
-                    Some(account) => account,
-                    None => {
-                        tracing::error!(?update, "Failed to decode account from update.");
-                        continue;
-                    }
-                };
-
-                let accumulator_messages = AccumulatorMessages::try_from_slice(&account.data);
-                match accumulator_messages {
-                    Ok(accumulator_messages) => {
-                        let (candidate, _) = Pubkey::find_program_address(
-                            &[
-                                b"AccumulatorState",
-                                &accumulator_messages.ring_index().to_be_bytes(),
-                            ],
-                            &system_program::id(),
-                        );
-
-                        if candidate.to_string() == update.value.pubkey {
-                            let store = store.clone();
-                            tokio::spawn(async move {
-                                if let Err(err) = Aggregates::store_update(
-                                    &*store,
-                                    Update::AccumulatorMessages(accumulator_messages),
-                                )
-                                .await
-                                {
-                                    tracing::error!(error = ?err, "Failed to store accumulator messages.");
-                                }
-                            });
-                        } else {
-                            tracing::error!(
-                                ?candidate,
-                                ?update.value.pubkey,
-                                "Failed to verify message public keys.",
-                            );
-                        }
-                    }
+    while let Some(update) = notif.next().await {
+        let account: Account = match update.value.account.decode() {
+            Some(account) => account,
+            None => {
+                tracing::error!(?update, "Failed to decode account from update.");
+                continue;
+            }
+        };
+
+        let accumulator_messages = AccumulatorMessages::try_from_slice(&account.data);
+        match accumulator_messages {
+            Ok(accumulator_messages) => {
+                let (candidate, _) = Pubkey::find_program_address(
+                    &[
+                        b"AccumulatorState",
+                        &accumulator_messages.ring_index().to_be_bytes(),
+                    ],
+                    &system_program::id(),
+                );
 
-                    Err(err) => {
-                        tracing::error!(error = ?err, "Failed to parse AccumulatorMessages.");
-                    }
-                };
+                if candidate.to_string() == update.value.pubkey {
+                    let store = store.clone();
+                    tokio::spawn(async move {
+                        if let Err(err) = Aggregates::store_update(
+                            &*store,
+                            Update::AccumulatorMessages(accumulator_messages),
+                        )
+                        .await
+                        {
+                            tracing::error!(error = ?err, "Failed to store accumulator messages.");
+                        }
+                    });
+                } else {
+                    tracing::error!(
+                        ?candidate,
+                        ?update.value.pubkey,
+                        "Failed to verify message public keys.",
+                    );
+                }
             }
-            None => {
-                return Err(anyhow!("Pythnet network listener terminated"));
+
+            Err(err) => {
+                tracing::error!(error = ?err, "Failed to parse AccumulatorMessages.");
             }
-        }
+        };
     }
+
+    Err(anyhow!("Pythnet network listener connection terminated"))
 }
 
 /// Fetch existing GuardianSet accounts from Wormhole.

apps/hermes/src/network/pythnet.rs

@@ -49,7 +49,11 @@ use {
         Digest,
         Keccak256,
     },
-    std::sync::Arc,
+    std::{
+        sync::Arc,
+        time::Duration,
+    },
+    tokio::time::Instant,
     tonic::Request,
     wormhole_sdk::{
         vaa::{
@@ -158,10 +162,16 @@ mod proto {
 pub async fn spawn(opts: RunOptions, state: Arc<State>) -> Result<()> {
     let mut exit = crate::EXIT.subscribe();
     loop {
+        let current_time = Instant::now();
         tokio::select! {
             _ = exit.changed() => break,
             Err(err) = run(opts.clone(), state.clone()) => {
                 tracing::error!(error = ?err, "Wormhole gRPC service failed.");
+
+                if current_time.elapsed() < Duration::from_secs(30) {
+                    tracing::error!("Wormhole listener restarting too quickly. Sleep 1s.");
+                    tokio::time::sleep(Duration::from_secs(1)).await;
+                }
             }
         }
     }
@@ -170,7 +180,7 @@ pub async fn spawn(opts: RunOptions, state: Arc<State>) -> Result<()> {
 }
 
 #[tracing::instrument(skip(opts, state))]
-async fn run(opts: RunOptions, state: Arc<State>) -> Result<()> {
+async fn run(opts: RunOptions, state: Arc<State>) -> Result<!> {
     let mut client = SpyRpcServiceClient::connect(opts.wormhole.spy_rpc_addr).await?;
     let mut stream = client
         .subscribe_signed_vaa(Request::new(SubscribeSignedVaaRequest {
@@ -190,7 +200,7 @@ async fn run(opts: RunOptions, state: Arc<State>) -> Result<()> {
         }
     }
 
-    Ok(())
+    Err(anyhow!("Wormhole gRPC stream terminated."))
 }
 
 /// Process a message received via a Wormhole gRPC connection.