FM-255: Skip broadcasting checkpoint signature if syncing

fendermint/vm/interpreter/src/fvm/exec.rs

@@ -142,29 +142,32 @@ where
                     .find(|v| v.public_key.0 == ctx.public_key)
                     .cloned()
                 {
-                    let secret_key = ctx.secret_key.clone();
-                    let broadcaster = ctx.broadcaster.clone();
-                    let gateway = self.gateway.clone();
-                    let chain_id = state.chain_id();
-
-                    tokio::spawn(async move {
-                        let height = checkpoint.block_height;
-
-                        let res = checkpoint::broadcast_signature(
-                            &broadcaster,
-                            &gateway,
-                            checkpoint,
-                            &power_table,
-                            &validator,
-                            &secret_key,
-                            chain_id,
-                        )
-                        .await;
-
-                        if let Err(e) = res {
-                            tracing::error!(error =? e, height, "error broadcasting checkpoint signature");
-                        }
-                    });
+                    // Do not resend past signatures.
+                    if !self.syncing().await? {
+                        let secret_key = ctx.secret_key.clone();
+                        let broadcaster = ctx.broadcaster.clone();
+                        let gateway = self.gateway.clone();
+                        let chain_id = state.chain_id();
+
+                        tokio::spawn(async move {
+                            let height = checkpoint.block_height;
+
+                            let res = checkpoint::broadcast_signature(
+                                &broadcaster,
+                                &gateway,
+                                checkpoint,
+                                &power_table,
+                                &validator,
+                                &secret_key,
+                                chain_id,
+                            )
+                            .await;
+
+                            if let Err(e) = res {
+                                tracing::error!(error =? e, height, "error broadcasting checkpoint signature");
+                            }
+                        });
+                    }
                 }
             }
 

fendermint/vm/interpreter/src/fvm/mod.rs

@@ -15,6 +15,7 @@ pub mod store;
 #[cfg(any(test, feature = "bundle"))]
 pub mod bundle;
 
+use anyhow::Context;
 pub use check::FvmCheckRet;
 pub use checkpoint::PowerUpdates;
 pub use exec::FvmApplyRet;
@@ -23,6 +24,7 @@ use fendermint_eth_hardhat::Hardhat;
 pub use fendermint_vm_message::query::FvmQuery;
 pub use genesis::FvmGenesisOutput;
 pub use query::FvmQueryRet;
+use tendermint_rpc::Client;
 
 pub use self::broadcast::Broadcaster;
 use self::state::ipc::GatewayCaller;
@@ -92,3 +94,19 @@ impl<DB, C> FvmMessageInterpreter<DB, C> {
         }
     }
 }
+
+impl<DB, C> FvmMessageInterpreter<DB, C>
+where
+    C: Client + Sync,
+{
+    /// Indicate that the node is syncing with the rest of the network and hasn't caught up with the tip yet.
+    async fn syncing(&self) -> anyhow::Result<bool> {
+        let status: tendermint_rpc::endpoint::status::Response = self
+            .client
+            .status()
+            .await
+            .context("failed to get Tendermint status")?;
+
+        Ok(status.sync_info.catching_up)
+    }
+}