From d9b44f44b72442a02bfc4d7c48ffc1d056cc35ab Mon Sep 17 00:00:00 2001
From: Xiangyi Zheng <xiangyi@near.org>
Date: Thu, 10 Oct 2024 16:24:17 -0700
Subject: [PATCH 1/8] modify is_stable to be indexer progressing and height
 caught up

---
 chain-signatures/node/src/mesh/connection.rs | 52 +++++++++++++++++++-
 chain-signatures/node/src/mesh/mod.rs        | 10 +++-
 chain-signatures/node/src/web/mod.rs         | 10 ++--
 3 files changed, 64 insertions(+), 8 deletions(-)

diff --git a/chain-signatures/node/src/mesh/connection.rs b/chain-signatures/node/src/mesh/connection.rs
index 310f4363..936c3836 100644
--- a/chain-signatures/node/src/mesh/connection.rs
+++ b/chain-signatures/node/src/mesh/connection.rs
@@ -2,6 +2,7 @@ use std::collections::HashMap;
 use std::time::{Duration, Instant};
 
 use cait_sith::protocol::Participant;
+use near_primitives::types::BlockHeight;
 use tokio::sync::RwLock;
 use url::Url;
 
@@ -165,13 +166,36 @@ impl Pool {
         self.potential_connections.read().await.clone()
     }
 
-    pub async fn is_participant_stable(&self, participant: &Participant) -> bool {
+    async fn max_block_height_among_participants(&self) -> BlockHeight {
+        self.status
+            .read()
+            .await
+            .values()
+            .filter_map(|state| {
+                if let StateView::Running {
+                    latest_block_height,
+                    ..
+                } = state
+                {
+                    Some(*latest_block_height)
+                } else {
+                    None
+                }
+            })
+            .max()
+            .unwrap_or(0)
+    }
+
+    pub async fn is_participant_indexer_progressing(&self, participant: &Participant) -> bool {
         self.status
             .read()
             .await
             .get(participant)
             .map_or(false, |state| match state {
-                StateView::Running { is_stable, .. } => *is_stable,
+                StateView::Running {
+                    is_indexer_progressing,
+                    ..
+                } => *is_indexer_progressing,
                 _ => false,
             })
     }
@@ -213,4 +237,28 @@ impl Pool {
         )
         .await
     }
+    
+    pub async fn is_participant_indexer_caught_up(&self, participant: &Participant) -> bool {
+        let max_block_height = self.max_block_height_among_participants().await;
+
+        if max_block_height == 0 {
+            return false;
+        }
+
+        let my_block_height = self
+            .status
+            .read()
+            .await
+            .get(participant)
+            .and_then(|state| match state {
+                StateView::Running {
+                    latest_block_height,
+                    ..
+                } => Some(*latest_block_height),
+                _ => None,
+            })
+            .unwrap_or(0);
+
+        (max_block_height - my_block_height) < 50
+    }
 }
diff --git a/chain-signatures/node/src/mesh/mod.rs b/chain-signatures/node/src/mesh/mod.rs
index 7dcedbcc..2ba03a01 100644
--- a/chain-signatures/node/src/mesh/mod.rs
+++ b/chain-signatures/node/src/mesh/mod.rs
@@ -89,7 +89,15 @@ impl Mesh {
     pub async fn stable_participants(&self) -> Participants {
         let mut stable = Participants::default();
         for (participant, info) in self.active_participants().iter() {
-            if self.connections.is_participant_stable(participant).await {
+            if self
+                .connections
+                .is_participant_indexer_progressing(participant)
+                .await
+                && self
+                    .connections
+                    .is_participant_indexer_caught_up(participant)
+                    .await
+            {
                 stable.insert(participant, info.clone());
             }
         }
diff --git a/chain-signatures/node/src/web/mod.rs b/chain-signatures/node/src/web/mod.rs
index 9161b05a..8e3f9d50 100644
--- a/chain-signatures/node/src/web/mod.rs
+++ b/chain-signatures/node/src/web/mod.rs
@@ -112,13 +112,13 @@ pub enum StateView {
         presignature_mine_count: usize,
         presignature_potential_count: usize,
         latest_block_height: BlockHeight,
-        is_stable: bool,
+        is_indexer_progressing: bool,
     },
     Resharing {
         old_participants: Vec<Participant>,
         new_participants: Vec<Participant>,
         latest_block_height: BlockHeight,
-        is_stable: bool,
+        is_indexer_progressing: bool,
     },
     Joining {
         participants: Vec<Participant>,
@@ -131,7 +131,7 @@ pub enum StateView {
 async fn state(Extension(state): Extension<Arc<AxumState>>) -> Result<Json<StateView>> {
     tracing::debug!("fetching state");
     let latest_block_height = state.indexer.latest_block_height().await;
-    let is_stable = state.indexer.is_on_track().await;
+    let is_indexer_progressing = state.indexer.is_on_track().await;
     let protocol_state = state.protocol_state.read().await;
 
     match &*protocol_state {
@@ -155,7 +155,7 @@ async fn state(Extension(state): Extension<Arc<AxumState>>) -> Result<Json<State
                 presignature_mine_count,
                 presignature_potential_count,
                 latest_block_height,
-                is_stable,
+                is_indexer_progressing,
             }))
         }
         NodeState::Resharing(state) => {
@@ -165,7 +165,7 @@ async fn state(Extension(state): Extension<Arc<AxumState>>) -> Result<Json<State
                 old_participants,
                 new_participants,
                 latest_block_height,
-                is_stable,
+                is_indexer_progressing,
             }))
         }
         NodeState::Joining(state) => {

From 430678b254b3958bd32def4bbb3998448a783de3 Mon Sep 17 00:00:00 2001
From: Xiangyi Zheng <xiangyi@near.org>
Date: Fri, 11 Oct 2024 13:15:39 -0700
Subject: [PATCH 2/8] pull max height from rpc endpoint

---
 chain-signatures/node/src/cli.rs             | 15 +++---
 chain-signatures/node/src/indexer.rs         | 38 ++++++++++++--
 chain-signatures/node/src/mesh/connection.rs | 52 +-------------------
 chain-signatures/node/src/mesh/mod.rs        | 10 +---
 chain-signatures/node/src/rpc_client.rs      | 17 +++++++
 chain-signatures/node/src/web/mod.rs         | 10 ++--
 6 files changed, 68 insertions(+), 74 deletions(-)

diff --git a/chain-signatures/node/src/cli.rs b/chain-signatures/node/src/cli.rs
index 25bbf744..77e372e6 100644
--- a/chain-signatures/node/src/cli.rs
+++ b/chain-signatures/node/src/cli.rs
@@ -193,12 +193,21 @@ pub fn run(cmd: Cli) -> anyhow::Result<()> {
                 .build()?;
             let gcp_service =
                 rt.block_on(async { GcpService::init(&account_id, &storage_options).await })?;
+
+            let mut rpc_client = near_fetch::Client::new(&near_rpc);
+            if let Some(referer_param) = client_header_referer {
+                let client_headers = rpc_client.inner_mut().headers_mut();
+                client_headers.insert(http::header::REFERER, referer_param.parse().unwrap());
+            }
+            tracing::info!(rpc_addr = rpc_client.rpc_addr(), "rpc client initialized");
+
             let (indexer_handle, indexer) = indexer::run(
                 &indexer_options,
                 &mpc_contract_id,
                 &account_id,
                 &sign_queue,
                 &gcp_service,
+                rpc_client.clone(),
                 &rt,
             )?;
 
@@ -222,13 +231,7 @@ pub fn run(cmd: Cli) -> anyhow::Result<()> {
             let (sender, receiver) = mpsc::channel(16384);
 
             tracing::info!(%my_address, "address detected");
-            let mut rpc_client = near_fetch::Client::new(&near_rpc);
-            if let Some(referer_param) = client_header_referer {
-                let client_headers = rpc_client.inner_mut().headers_mut();
-                client_headers.insert(http::header::REFERER, referer_param.parse().unwrap());
-            }
 
-            tracing::info!(rpc_addr = rpc_client.rpc_addr(), "rpc client initialized");
             let signer = InMemorySigner::from_secret_key(account_id.clone(), account_sk);
             let (protocol, protocol_state) = MpcSignProtocol::init(
                 my_address,
diff --git a/chain-signatures/node/src/indexer.rs b/chain-signatures/node/src/indexer.rs
index 4239dd55..d944e66b 100644
--- a/chain-signatures/node/src/indexer.rs
+++ b/chain-signatures/node/src/indexer.rs
@@ -1,6 +1,7 @@
 use crate::gcp::error::DatastoreStorageError;
 use crate::gcp::GcpService;
 use crate::protocol::{SignQueue, SignRequest};
+use crate::rpc_client;
 use crate::types::LatestBlockHeight;
 use crypto_shared::{derive_epsilon, ScalarExt};
 use k256::Scalar;
@@ -53,6 +54,14 @@ pub struct Options {
     /// The threshold in seconds to check if the indexer needs to be restarted due to it stalling.
     #[clap(long, env("MPC_INDEXER_RUNNING_THRESHOLD"), default_value = "300")]
     pub running_threshold: u64,
+
+    /// The threshold in block height lag to check if the indexer has caught up.
+    #[clap(
+        long,
+        env("MPC_INDEXER_BLOCK_HEIGHT_LAG_THRESHOLD"),
+        default_value = "50"
+    )]
+    pub block_height_lag_threshold: u64,
 }
 
 impl Options {
@@ -68,6 +77,8 @@ impl Options {
             self.behind_threshold.to_string(),
             "--running-threshold".to_string(),
             self.running_threshold.to_string(),
+            "--block-height-lag-threshold".to_string(),
+            self.block_height_lag_threshold.to_string(),
         ];
 
         if let Some(s3_url) = self.s3_url {
@@ -105,10 +116,16 @@ pub struct Indexer {
     last_updated_timestamp: Arc<RwLock<Instant>>,
     running_threshold: Duration,
     behind_threshold: Duration,
+    block_height_lag_threshold: u64,
+    rpc_client: near_fetch::Client,
 }
 
 impl Indexer {
-    fn new(latest_block_height: LatestBlockHeight, options: &Options) -> Self {
+    fn new(
+        latest_block_height: LatestBlockHeight,
+        options: &Options,
+        rpc_client: near_fetch::Client,
+    ) -> Self {
         tracing::info!(
             "creating new indexer, latest block height: {}",
             latest_block_height.block_height
@@ -118,6 +135,8 @@ impl Indexer {
             last_updated_timestamp: Arc::new(RwLock::new(Instant::now())),
             running_threshold: Duration::from_secs(options.running_threshold),
             behind_threshold: Duration::from_secs(options.behind_threshold),
+            block_height_lag_threshold: options.block_height_lag_threshold,
+            rpc_client,
         }
     }
 
@@ -126,7 +145,7 @@ impl Indexer {
         self.latest_block_height.read().await.block_height
     }
 
-    /// Check whether the indexer is on track with the latest block height from the chain.
+    /// Check whether the indexer block height has been updated recently.
     pub async fn is_on_track(&self) -> bool {
         self.last_updated_timestamp.read().await.elapsed() <= self.behind_threshold
     }
@@ -138,7 +157,17 @@ impl Indexer {
 
     /// Check whether the indexer is behind with the latest block height from the chain.
     pub async fn is_behind(&self) -> bool {
-        self.last_updated_timestamp.read().await.elapsed() > self.behind_threshold
+        let network_latest_height = rpc_client::fetch_latest_block_height(&self.rpc_client).await;
+        if let Ok(network_latest_height) = network_latest_height {
+            self.latest_block_height().await
+                < network_latest_height - self.block_height_lag_threshold
+        } else {
+            false
+        }
+    }
+
+    pub async fn is_stable(&self) -> bool {
+        !self.is_behind().await && self.is_on_track().await
     }
 
     async fn update_block_height(
@@ -287,6 +316,7 @@ pub fn run(
     node_account_id: &AccountId,
     queue: &Arc<RwLock<SignQueue>>,
     gcp_service: &crate::gcp::GcpService,
+    rpc_client: near_fetch::Client,
     rt: &tokio::runtime::Runtime,
 ) -> anyhow::Result<(JoinHandle<anyhow::Result<()>>, Indexer)> {
     tracing::info!(
@@ -311,7 +341,7 @@ pub fn run(
         }
     });
 
-    let indexer = Indexer::new(latest_block_height, options);
+    let indexer = Indexer::new(latest_block_height, options, rpc_client);
     let context = Context {
         mpc_contract_id: mpc_contract_id.clone(),
         node_account_id: node_account_id.clone(),
diff --git a/chain-signatures/node/src/mesh/connection.rs b/chain-signatures/node/src/mesh/connection.rs
index 936c3836..310f4363 100644
--- a/chain-signatures/node/src/mesh/connection.rs
+++ b/chain-signatures/node/src/mesh/connection.rs
@@ -2,7 +2,6 @@ use std::collections::HashMap;
 use std::time::{Duration, Instant};
 
 use cait_sith::protocol::Participant;
-use near_primitives::types::BlockHeight;
 use tokio::sync::RwLock;
 use url::Url;
 
@@ -166,36 +165,13 @@ impl Pool {
         self.potential_connections.read().await.clone()
     }
 
-    async fn max_block_height_among_participants(&self) -> BlockHeight {
-        self.status
-            .read()
-            .await
-            .values()
-            .filter_map(|state| {
-                if let StateView::Running {
-                    latest_block_height,
-                    ..
-                } = state
-                {
-                    Some(*latest_block_height)
-                } else {
-                    None
-                }
-            })
-            .max()
-            .unwrap_or(0)
-    }
-
-    pub async fn is_participant_indexer_progressing(&self, participant: &Participant) -> bool {
+    pub async fn is_participant_stable(&self, participant: &Participant) -> bool {
         self.status
             .read()
             .await
             .get(participant)
             .map_or(false, |state| match state {
-                StateView::Running {
-                    is_indexer_progressing,
-                    ..
-                } => *is_indexer_progressing,
+                StateView::Running { is_stable, .. } => *is_stable,
                 _ => false,
             })
     }
@@ -237,28 +213,4 @@ impl Pool {
         )
         .await
     }
-    
-    pub async fn is_participant_indexer_caught_up(&self, participant: &Participant) -> bool {
-        let max_block_height = self.max_block_height_among_participants().await;
-
-        if max_block_height == 0 {
-            return false;
-        }
-
-        let my_block_height = self
-            .status
-            .read()
-            .await
-            .get(participant)
-            .and_then(|state| match state {
-                StateView::Running {
-                    latest_block_height,
-                    ..
-                } => Some(*latest_block_height),
-                _ => None,
-            })
-            .unwrap_or(0);
-
-        (max_block_height - my_block_height) < 50
-    }
 }
diff --git a/chain-signatures/node/src/mesh/mod.rs b/chain-signatures/node/src/mesh/mod.rs
index 2ba03a01..7dcedbcc 100644
--- a/chain-signatures/node/src/mesh/mod.rs
+++ b/chain-signatures/node/src/mesh/mod.rs
@@ -89,15 +89,7 @@ impl Mesh {
     pub async fn stable_participants(&self) -> Participants {
         let mut stable = Participants::default();
         for (participant, info) in self.active_participants().iter() {
-            if self
-                .connections
-                .is_participant_indexer_progressing(participant)
-                .await
-                && self
-                    .connections
-                    .is_participant_indexer_caught_up(participant)
-                    .await
-            {
+            if self.connections.is_participant_stable(participant).await {
                 stable.insert(participant, info.clone());
             }
         }
diff --git a/chain-signatures/node/src/rpc_client.rs b/chain-signatures/node/src/rpc_client.rs
index 6917af9b..b0298261 100644
--- a/chain-signatures/node/src/rpc_client.rs
+++ b/chain-signatures/node/src/rpc_client.rs
@@ -4,6 +4,7 @@ use crate::protocol::ProtocolState;
 use near_account_id::AccountId;
 use near_crypto::InMemorySigner;
 
+use near_primitives::types::BlockHeight;
 use serde_json::json;
 
 pub async fn fetch_mpc_contract_state(
@@ -99,3 +100,19 @@ pub async fn vote_reshared(
 
     Ok(result)
 }
+
+pub async fn fetch_latest_block_height(
+    rpc_client: &near_fetch::Client,
+) -> anyhow::Result<BlockHeight> {
+    let latest_block_height: BlockHeight = rpc_client
+        .view_block()
+        .await
+        .map_err(|e| {
+            tracing::warn!(%e, "failed to fetch latest block");
+            e
+        })?
+        .header
+        .height;
+    tracing::debug!(latest_block_height, "latest block height");
+    Ok(latest_block_height)
+}
diff --git a/chain-signatures/node/src/web/mod.rs b/chain-signatures/node/src/web/mod.rs
index 8e3f9d50..3e045cc6 100644
--- a/chain-signatures/node/src/web/mod.rs
+++ b/chain-signatures/node/src/web/mod.rs
@@ -112,13 +112,13 @@ pub enum StateView {
         presignature_mine_count: usize,
         presignature_potential_count: usize,
         latest_block_height: BlockHeight,
-        is_indexer_progressing: bool,
+        is_stable: bool,
     },
     Resharing {
         old_participants: Vec<Participant>,
         new_participants: Vec<Participant>,
         latest_block_height: BlockHeight,
-        is_indexer_progressing: bool,
+        is_stable: bool,
     },
     Joining {
         participants: Vec<Participant>,
@@ -131,7 +131,7 @@ pub enum StateView {
 async fn state(Extension(state): Extension<Arc<AxumState>>) -> Result<Json<StateView>> {
     tracing::debug!("fetching state");
     let latest_block_height = state.indexer.latest_block_height().await;
-    let is_indexer_progressing = state.indexer.is_on_track().await;
+    let is_stable = state.indexer.is_stable().await;
     let protocol_state = state.protocol_state.read().await;
 
     match &*protocol_state {
@@ -155,7 +155,7 @@ async fn state(Extension(state): Extension<Arc<AxumState>>) -> Result<Json<State
                 presignature_mine_count,
                 presignature_potential_count,
                 latest_block_height,
-                is_indexer_progressing,
+                is_stable,
             }))
         }
         NodeState::Resharing(state) => {
@@ -165,7 +165,7 @@ async fn state(Extension(state): Extension<Arc<AxumState>>) -> Result<Json<State
                 old_participants,
                 new_participants,
                 latest_block_height,
-                is_indexer_progressing,
+                is_stable,
             }))
         }
         NodeState::Joining(state) => {

From ae3f37fed2bdd37a2eee9d13facafeb4261306c7 Mon Sep 17 00:00:00 2001
From: Xiangyi Zheng <xiangyi@near.org>
Date: Fri, 11 Oct 2024 14:32:30 -0700
Subject: [PATCH 3/8] fix integration tests

---
 integration-tests/chain-signatures/src/containers.rs | 1 +
 integration-tests/chain-signatures/src/local.rs      | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/integration-tests/chain-signatures/src/containers.rs b/integration-tests/chain-signatures/src/containers.rs
index b6b69d17..f719fdef 100644
--- a/integration-tests/chain-signatures/src/containers.rs
+++ b/integration-tests/chain-signatures/src/containers.rs
@@ -99,6 +99,7 @@ impl<'a> Node<'a> {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
+            block_height_lag_threshold: 50,
         };
 
         let args = mpc_node::cli::Cli::Start {
diff --git a/integration-tests/chain-signatures/src/local.rs b/integration-tests/chain-signatures/src/local.rs
index 923ccb15..5c050f05 100644
--- a/integration-tests/chain-signatures/src/local.rs
+++ b/integration-tests/chain-signatures/src/local.rs
@@ -55,6 +55,7 @@ impl Node {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
+            block_height_lag_threshold: 50,
         };
         let near_rpc = ctx.lake_indexer.rpc_host_address.clone();
         let mpc_contract_id = ctx.mpc_contract.id().clone();
@@ -150,6 +151,7 @@ impl Node {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
+            block_height_lag_threshold: 50,
         };
         let cli = mpc_node::cli::Cli::Start {
             near_rpc: config.near_rpc.clone(),

From 2fd361a007a5f5494a1611b45af4367649ef2942 Mon Sep 17 00:00:00 2001
From: Xiangyi Zheng <xiangyi@near.org>
Date: Tue, 15 Oct 2024 14:36:30 -0700
Subject: [PATCH 4/8] address comments

---
 chain-signatures/node/src/indexer.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/chain-signatures/node/src/indexer.rs b/chain-signatures/node/src/indexer.rs
index d944e66b..87d56380 100644
--- a/chain-signatures/node/src/indexer.rs
+++ b/chain-signatures/node/src/indexer.rs
@@ -162,7 +162,7 @@ impl Indexer {
             self.latest_block_height().await
                 < network_latest_height - self.block_height_lag_threshold
         } else {
-            false
+            true
         }
     }
 

From 04da1fafc4ddda8b6e8c7b1d3e20c9cd2ba14d1b Mon Sep 17 00:00:00 2001
From: Xiangyi Zheng <xiangyi@near.org>
Date: Wed, 16 Oct 2024 15:15:45 -0700
Subject: [PATCH 5/8] use 200 as default to allow 3 min delay from latest rpc
 fetch

---
 chain-signatures/node/src/indexer.rs                 | 2 +-
 integration-tests/chain-signatures/src/containers.rs | 2 +-
 integration-tests/chain-signatures/src/local.rs      | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/chain-signatures/node/src/indexer.rs b/chain-signatures/node/src/indexer.rs
index 87d56380..65520c34 100644
--- a/chain-signatures/node/src/indexer.rs
+++ b/chain-signatures/node/src/indexer.rs
@@ -59,7 +59,7 @@ pub struct Options {
     #[clap(
         long,
         env("MPC_INDEXER_BLOCK_HEIGHT_LAG_THRESHOLD"),
-        default_value = "50"
+        default_value = "200"
     )]
     pub block_height_lag_threshold: u64,
 }
diff --git a/integration-tests/chain-signatures/src/containers.rs b/integration-tests/chain-signatures/src/containers.rs
index f719fdef..6801548f 100644
--- a/integration-tests/chain-signatures/src/containers.rs
+++ b/integration-tests/chain-signatures/src/containers.rs
@@ -99,7 +99,7 @@ impl<'a> Node<'a> {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
-            block_height_lag_threshold: 50,
+            block_height_lag_threshold: 200,
         };
 
         let args = mpc_node::cli::Cli::Start {
diff --git a/integration-tests/chain-signatures/src/local.rs b/integration-tests/chain-signatures/src/local.rs
index 5c050f05..b930dd53 100644
--- a/integration-tests/chain-signatures/src/local.rs
+++ b/integration-tests/chain-signatures/src/local.rs
@@ -55,7 +55,7 @@ impl Node {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
-            block_height_lag_threshold: 50,
+            block_height_lag_threshold: 200,
         };
         let near_rpc = ctx.lake_indexer.rpc_host_address.clone();
         let mpc_contract_id = ctx.mpc_contract.id().clone();
@@ -151,7 +151,7 @@ impl Node {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
-            block_height_lag_threshold: 50,
+            block_height_lag_threshold: 200,
         };
         let cli = mpc_node::cli::Cli::Start {
             near_rpc: config.near_rpc.clone(),

From 04a9e9fcfc541c71458d64211ab81e170389625f Mon Sep 17 00:00:00 2001
From: Xiangyi Zheng <xiangyi@near.org>
Date: Thu, 17 Oct 2024 06:56:17 -0700
Subject: [PATCH 6/8] in progress

---
 integration-tests/chain-signatures/src/containers.rs | 2 +-
 integration-tests/chain-signatures/src/local.rs      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/integration-tests/chain-signatures/src/containers.rs b/integration-tests/chain-signatures/src/containers.rs
index 6801548f..3ad699ea 100644
--- a/integration-tests/chain-signatures/src/containers.rs
+++ b/integration-tests/chain-signatures/src/containers.rs
@@ -99,7 +99,7 @@ impl<'a> Node<'a> {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
-            block_height_lag_threshold: 200,
+            block_height_lag_threshold: 2000,
         };
 
         let args = mpc_node::cli::Cli::Start {
diff --git a/integration-tests/chain-signatures/src/local.rs b/integration-tests/chain-signatures/src/local.rs
index b930dd53..436bd7e2 100644
--- a/integration-tests/chain-signatures/src/local.rs
+++ b/integration-tests/chain-signatures/src/local.rs
@@ -55,7 +55,7 @@ impl Node {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
-            block_height_lag_threshold: 200,
+            block_height_lag_threshold: 2000,
         };
         let near_rpc = ctx.lake_indexer.rpc_host_address.clone();
         let mpc_contract_id = ctx.mpc_contract.id().clone();
@@ -151,7 +151,7 @@ impl Node {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
-            block_height_lag_threshold: 200,
+            block_height_lag_threshold: 2000,
         };
         let cli = mpc_node::cli::Cli::Start {
             near_rpc: config.near_rpc.clone(),

From f9f368623cec9aabc54f421caf74398cd0316062 Mon Sep 17 00:00:00 2001
From: Xiangyi Zheng <xiangyi@near.org>
Date: Tue, 29 Oct 2024 17:17:42 -0700
Subject: [PATCH 7/8] use block.header().timestamp_nanoseconds instead of
 fetching latest block with rpc client

---
 chain-signatures/node/src/cli.rs              | 15 ++---
 chain-signatures/node/src/indexer.rs          | 58 +++++++------------
 chain-signatures/node/src/rpc_client.rs       | 17 ------
 .../chain-signatures/src/containers.rs        |  1 -
 .../chain-signatures/src/local.rs             |  2 -
 5 files changed, 28 insertions(+), 65 deletions(-)

diff --git a/chain-signatures/node/src/cli.rs b/chain-signatures/node/src/cli.rs
index 77e372e6..25bbf744 100644
--- a/chain-signatures/node/src/cli.rs
+++ b/chain-signatures/node/src/cli.rs
@@ -193,21 +193,12 @@ pub fn run(cmd: Cli) -> anyhow::Result<()> {
                 .build()?;
             let gcp_service =
                 rt.block_on(async { GcpService::init(&account_id, &storage_options).await })?;
-
-            let mut rpc_client = near_fetch::Client::new(&near_rpc);
-            if let Some(referer_param) = client_header_referer {
-                let client_headers = rpc_client.inner_mut().headers_mut();
-                client_headers.insert(http::header::REFERER, referer_param.parse().unwrap());
-            }
-            tracing::info!(rpc_addr = rpc_client.rpc_addr(), "rpc client initialized");
-
             let (indexer_handle, indexer) = indexer::run(
                 &indexer_options,
                 &mpc_contract_id,
                 &account_id,
                 &sign_queue,
                 &gcp_service,
-                rpc_client.clone(),
                 &rt,
             )?;
 
@@ -231,7 +222,13 @@ pub fn run(cmd: Cli) -> anyhow::Result<()> {
             let (sender, receiver) = mpsc::channel(16384);
 
             tracing::info!(%my_address, "address detected");
+            let mut rpc_client = near_fetch::Client::new(&near_rpc);
+            if let Some(referer_param) = client_header_referer {
+                let client_headers = rpc_client.inner_mut().headers_mut();
+                client_headers.insert(http::header::REFERER, referer_param.parse().unwrap());
+            }
 
+            tracing::info!(rpc_addr = rpc_client.rpc_addr(), "rpc client initialized");
             let signer = InMemorySigner::from_secret_key(account_id.clone(), account_sk);
             let (protocol, protocol_state) = MpcSignProtocol::init(
                 my_address,
diff --git a/chain-signatures/node/src/indexer.rs b/chain-signatures/node/src/indexer.rs
index 65520c34..b652c0e5 100644
--- a/chain-signatures/node/src/indexer.rs
+++ b/chain-signatures/node/src/indexer.rs
@@ -1,7 +1,6 @@
 use crate::gcp::error::DatastoreStorageError;
 use crate::gcp::GcpService;
 use crate::protocol::{SignQueue, SignRequest};
-use crate::rpc_client;
 use crate::types::LatestBlockHeight;
 use crypto_shared::{derive_epsilon, ScalarExt};
 use k256::Scalar;
@@ -48,20 +47,12 @@ pub struct Options {
     pub start_block_height: u64,
 
     /// The amount of time before we should that our indexer is behind.
-    #[clap(long, env("MPC_INDEXER_BEHIND_THRESHOLD"), default_value = "180")]
+    #[clap(long, env("MPC_INDEXER_BEHIND_THRESHOLD"), default_value = "200")]
     pub behind_threshold: u64,
 
     /// The threshold in seconds to check if the indexer needs to be restarted due to it stalling.
     #[clap(long, env("MPC_INDEXER_RUNNING_THRESHOLD"), default_value = "300")]
     pub running_threshold: u64,
-
-    /// The threshold in block height lag to check if the indexer has caught up.
-    #[clap(
-        long,
-        env("MPC_INDEXER_BLOCK_HEIGHT_LAG_THRESHOLD"),
-        default_value = "200"
-    )]
-    pub block_height_lag_threshold: u64,
 }
 
 impl Options {
@@ -77,8 +68,6 @@ impl Options {
             self.behind_threshold.to_string(),
             "--running-threshold".to_string(),
             self.running_threshold.to_string(),
-            "--block-height-lag-threshold".to_string(),
-            self.block_height_lag_threshold.to_string(),
         ];
 
         if let Some(s3_url) = self.s3_url {
@@ -114,18 +103,13 @@ pub struct ContractSignRequest {
 pub struct Indexer {
     latest_block_height: Arc<RwLock<LatestBlockHeight>>,
     last_updated_timestamp: Arc<RwLock<Instant>>,
+    latest_block_timestamp_nanoseconds: Arc<RwLock<Option<u64>>>,
     running_threshold: Duration,
     behind_threshold: Duration,
-    block_height_lag_threshold: u64,
-    rpc_client: near_fetch::Client,
 }
 
 impl Indexer {
-    fn new(
-        latest_block_height: LatestBlockHeight,
-        options: &Options,
-        rpc_client: near_fetch::Client,
-    ) -> Self {
+    fn new(latest_block_height: LatestBlockHeight, options: &Options) -> Self {
         tracing::info!(
             "creating new indexer, latest block height: {}",
             latest_block_height.block_height
@@ -133,10 +117,9 @@ impl Indexer {
         Self {
             latest_block_height: Arc::new(RwLock::new(latest_block_height)),
             last_updated_timestamp: Arc::new(RwLock::new(Instant::now())),
+            latest_block_timestamp_nanoseconds: Arc::new(RwLock::new(None)),
             running_threshold: Duration::from_secs(options.running_threshold),
             behind_threshold: Duration::from_secs(options.behind_threshold),
-            block_height_lag_threshold: options.block_height_lag_threshold,
-            rpc_client,
         }
     }
 
@@ -145,11 +128,6 @@ impl Indexer {
         self.latest_block_height.read().await.block_height
     }
 
-    /// Check whether the indexer block height has been updated recently.
-    pub async fn is_on_track(&self) -> bool {
-        self.last_updated_timestamp.read().await.elapsed() <= self.behind_threshold
-    }
-
     /// Check whether the indexer is on track with the latest block height from the chain.
     pub async fn is_running(&self) -> bool {
         self.last_updated_timestamp.read().await.elapsed() <= self.running_threshold
@@ -157,26 +135,31 @@ impl Indexer {
 
     /// Check whether the indexer is behind with the latest block height from the chain.
     pub async fn is_behind(&self) -> bool {
-        let network_latest_height = rpc_client::fetch_latest_block_height(&self.rpc_client).await;
-        if let Ok(network_latest_height) = network_latest_height {
-            self.latest_block_height().await
-                < network_latest_height - self.block_height_lag_threshold
+        if let Some(latest_block_timestamp_nanoseconds) =
+            *self.latest_block_timestamp_nanoseconds.read().await
+        {
+            crate::util::is_elapsed_longer_than_timeout(
+                latest_block_timestamp_nanoseconds / 1000000000,
+                self.behind_threshold.as_millis() as u64,
+            )
         } else {
             true
         }
     }
 
     pub async fn is_stable(&self) -> bool {
-        !self.is_behind().await && self.is_on_track().await
+        !self.is_behind().await && self.is_running().await
     }
 
-    async fn update_block_height(
+    async fn update_block_height_and_timestamp(
         &self,
         block_height: BlockHeight,
+        block_timestamp_nanoseconds: u64,
         gcp: &GcpService,
     ) -> Result<(), DatastoreStorageError> {
-        tracing::debug!(block_height, "update_block_height");
+        tracing::debug!(block_height, "update_block_height_and_timestamp");
         *self.last_updated_timestamp.write().await = Instant::now();
+        *self.latest_block_timestamp_nanoseconds.write().await = Some(block_timestamp_nanoseconds);
         self.latest_block_height
             .write()
             .await
@@ -280,7 +263,11 @@ async fn handle_block(
     }
 
     ctx.indexer
-        .update_block_height(block.block_height(), &ctx.gcp_service)
+        .update_block_height_and_timestamp(
+            block.block_height(),
+            block.header().timestamp_nanosec(),
+            &ctx.gcp_service,
+        )
         .await?;
 
     crate::metrics::LATEST_BLOCK_HEIGHT
@@ -316,7 +303,6 @@ pub fn run(
     node_account_id: &AccountId,
     queue: &Arc<RwLock<SignQueue>>,
     gcp_service: &crate::gcp::GcpService,
-    rpc_client: near_fetch::Client,
     rt: &tokio::runtime::Runtime,
 ) -> anyhow::Result<(JoinHandle<anyhow::Result<()>>, Indexer)> {
     tracing::info!(
@@ -341,7 +327,7 @@ pub fn run(
         }
     });
 
-    let indexer = Indexer::new(latest_block_height, options, rpc_client);
+    let indexer = Indexer::new(latest_block_height, options);
     let context = Context {
         mpc_contract_id: mpc_contract_id.clone(),
         node_account_id: node_account_id.clone(),
diff --git a/chain-signatures/node/src/rpc_client.rs b/chain-signatures/node/src/rpc_client.rs
index b0298261..6917af9b 100644
--- a/chain-signatures/node/src/rpc_client.rs
+++ b/chain-signatures/node/src/rpc_client.rs
@@ -4,7 +4,6 @@ use crate::protocol::ProtocolState;
 use near_account_id::AccountId;
 use near_crypto::InMemorySigner;
 
-use near_primitives::types::BlockHeight;
 use serde_json::json;
 
 pub async fn fetch_mpc_contract_state(
@@ -100,19 +99,3 @@ pub async fn vote_reshared(
 
     Ok(result)
 }
-
-pub async fn fetch_latest_block_height(
-    rpc_client: &near_fetch::Client,
-) -> anyhow::Result<BlockHeight> {
-    let latest_block_height: BlockHeight = rpc_client
-        .view_block()
-        .await
-        .map_err(|e| {
-            tracing::warn!(%e, "failed to fetch latest block");
-            e
-        })?
-        .header
-        .height;
-    tracing::debug!(latest_block_height, "latest block height");
-    Ok(latest_block_height)
-}
diff --git a/integration-tests/chain-signatures/src/containers.rs b/integration-tests/chain-signatures/src/containers.rs
index 3ad699ea..b6b69d17 100644
--- a/integration-tests/chain-signatures/src/containers.rs
+++ b/integration-tests/chain-signatures/src/containers.rs
@@ -99,7 +99,6 @@ impl<'a> Node<'a> {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
-            block_height_lag_threshold: 2000,
         };
 
         let args = mpc_node::cli::Cli::Start {
diff --git a/integration-tests/chain-signatures/src/local.rs b/integration-tests/chain-signatures/src/local.rs
index 436bd7e2..923ccb15 100644
--- a/integration-tests/chain-signatures/src/local.rs
+++ b/integration-tests/chain-signatures/src/local.rs
@@ -55,7 +55,6 @@ impl Node {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
-            block_height_lag_threshold: 2000,
         };
         let near_rpc = ctx.lake_indexer.rpc_host_address.clone();
         let mpc_contract_id = ctx.mpc_contract.id().clone();
@@ -151,7 +150,6 @@ impl Node {
             start_block_height: 0,
             running_threshold: 120,
             behind_threshold: 120,
-            block_height_lag_threshold: 2000,
         };
         let cli = mpc_node::cli::Cli::Start {
             near_rpc: config.near_rpc.clone(),

From 6c792ec4de92da954298d5622ff178bd5ce1531b Mon Sep 17 00:00:00 2001
From: Xiangyi Zheng <xiangyi@near.org>
Date: Tue, 29 Oct 2024 17:31:50 -0700
Subject: [PATCH 8/8] rename

---
 chain-signatures/node/src/indexer.rs | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/chain-signatures/node/src/indexer.rs b/chain-signatures/node/src/indexer.rs
index b652c0e5..a744b69d 100644
--- a/chain-signatures/node/src/indexer.rs
+++ b/chain-signatures/node/src/indexer.rs
@@ -103,7 +103,7 @@ pub struct ContractSignRequest {
 pub struct Indexer {
     latest_block_height: Arc<RwLock<LatestBlockHeight>>,
     last_updated_timestamp: Arc<RwLock<Instant>>,
-    latest_block_timestamp_nanoseconds: Arc<RwLock<Option<u64>>>,
+    latest_block_timestamp_nanosec: Arc<RwLock<Option<u64>>>,
     running_threshold: Duration,
     behind_threshold: Duration,
 }
@@ -117,7 +117,7 @@ impl Indexer {
         Self {
             latest_block_height: Arc::new(RwLock::new(latest_block_height)),
             last_updated_timestamp: Arc::new(RwLock::new(Instant::now())),
-            latest_block_timestamp_nanoseconds: Arc::new(RwLock::new(None)),
+            latest_block_timestamp_nanosec: Arc::new(RwLock::new(None)),
             running_threshold: Duration::from_secs(options.running_threshold),
             behind_threshold: Duration::from_secs(options.behind_threshold),
         }
@@ -135,11 +135,11 @@ impl Indexer {
 
     /// Check whether the indexer is behind with the latest block height from the chain.
     pub async fn is_behind(&self) -> bool {
-        if let Some(latest_block_timestamp_nanoseconds) =
-            *self.latest_block_timestamp_nanoseconds.read().await
+        if let Some(latest_block_timestamp_nanosec) =
+            *self.latest_block_timestamp_nanosec.read().await
         {
             crate::util::is_elapsed_longer_than_timeout(
-                latest_block_timestamp_nanoseconds / 1000000000,
+                latest_block_timestamp_nanosec / 1_000_000_000,
                 self.behind_threshold.as_millis() as u64,
             )
         } else {
@@ -154,12 +154,12 @@ impl Indexer {
     async fn update_block_height_and_timestamp(
         &self,
         block_height: BlockHeight,
-        block_timestamp_nanoseconds: u64,
+        block_timestamp_nanosec: u64,
         gcp: &GcpService,
     ) -> Result<(), DatastoreStorageError> {
         tracing::debug!(block_height, "update_block_height_and_timestamp");
         *self.last_updated_timestamp.write().await = Instant::now();
-        *self.latest_block_timestamp_nanoseconds.write().await = Some(block_timestamp_nanoseconds);
+        *self.latest_block_timestamp_nanosec.write().await = Some(block_timestamp_nanosec);
         self.latest_block_height
             .write()
             .await