LB check functionality updates

Author: finiteops

crates/rpc/rpc-eth-api/src/core.rs

@@ -47,20 +47,14 @@ impl<T> FullEthApiServer for T where
 {
 }
 
-/// Bitfinity lag API
-pub const LAG_STATUS_BAD: &str = "LAGGING";
-
-/// Bitfinity lag API
-pub const LAG_STATUS_OK: &str = "ACCEPTED_LAG";
-
 /// Eth rpc interface: <https://ethereum.github.io/execution-apis/api-documentation/>
 #[cfg_attr(not(feature = "client"), rpc(server, namespace = "eth"))]
 #[cfg_attr(feature = "client", rpc(server, client, namespace = "eth"))]
 pub trait EthApi<T: RpcObject, B: RpcObject, R: RpcObject, H: RpcObject> {
-    /// Bitfinity LB api extenstion
-    /// Handler for: `eth_lagging`
-    #[method(name = "lagging")]
-    async fn lagging(&self, accepted_lag: Option<U64>) -> RpcResult<String>;
+    /// Bitfinity LB api extension
+    /// Handler for: `eth_lbLagCheck`
+    #[method(name = "lbLagCheck")]
+    async fn lb_lag_check(&self, accepted_lag: Option<U64>) -> RpcResult<String>;
 
     /// Returns the protocol version encoded as a string.
     #[method(name = "protocolVersion")]
@@ -397,22 +391,32 @@ where
     T: FullEthApi,
     jsonrpsee_types::error::ErrorObject<'static>: From<T::Error>,
 {
-    /// Handler for: `eth_lagging`
-    async fn lagging(&self, accepted_lag: Option<U64>) -> RpcResult<String> {
+    /// Handler for: `eth_lbLagCheck`
+    async fn lb_lag_check(&self, accepted_lag: Option<U64>) -> RpcResult<String> {
+        const LAG_STATUS_BAD: &str = "LAGGING";
+        const LAG_STATUS_OK: &str = "ACCEPTED_LAG";
+        let network_block = match BitfinityEvmRpc::network_block_number(self).await {
+            Ok(block) => block,
+            Err(e) => {
+                // Must not fail if rpc-url/evmc is not responding
+                // or it would to break nodes cluster -> LB will stop traffic
+                tracing::error!(target: "rpc::eth", "Failed to get block number from the network. {}", e);
+                return Ok(format!("{}: NO_SOURCE", LAG_STATUS_OK));
+            }
+        };
+
         let accepted_lag = match accepted_lag {
             Some(lag) => U256::from(lag),
             // Assuming that lag behind for 3 block is ok
             None => U256::from(3),
         };
 
-        let network_block = BitfinityEvmRpc::network_block_number(self).await?;
         let node_block = self.block_number()?;
         let lag = network_block.saturating_sub(node_block);
 
-        let status =
-            if lag > accepted_lag { LAG_STATUS_BAD.to_owned() } else { LAG_STATUS_OK.to_owned() };
+        let status = if lag > accepted_lag { LAG_STATUS_BAD } else { LAG_STATUS_OK };
 
-        // Better to repond with string that add structure, import serde and stuff
+        // Better to respond with string that add structure, import serde and stuff
         let response =
             format!("{}: lag: {} node: {} network: {}", status, lag, node_block, network_block);