grpc: add a metdata feed to indicate missing account, snapshot start and end

connector/examples/combined_example_consumer.rs

@@ -98,6 +98,7 @@ async fn main() -> anyhow::Result<()> {
         &config,
         &filter_config,
         account_write_queue_sender,
+        None,
         slot_queue_sender,
         metrics_tx.clone(),
         exit.clone(),

connector/examples/geyser_example_consumer.rs

@@ -98,6 +98,7 @@ async fn main() -> anyhow::Result<()> {
         &config,
         &filter_config,
         account_write_queue_sender,
+        None,
         slot_queue_sender,
         metrics_tx.clone(),
         exit.clone(),

connector/src/grpc_plugin_source.rs

@@ -27,7 +27,8 @@ use crate::snapshot::{get_snapshot_gma, get_snapshot_gpa};
 use crate::{
     chain_data::SlotStatus,
     metrics::{MetricType, Metrics},
-    AccountWrite, GrpcSourceConfig, SlotUpdate, SnapshotSourceConfig, SourceConfig, TlsConfig,
+    AccountWrite, FeedMetadata, GrpcSourceConfig, SlotUpdate, SnapshotSourceConfig, SourceConfig,
+    TlsConfig,
 };
 use crate::{EntityFilter, FilterConfig};
 
@@ -415,6 +416,7 @@ pub async fn process_events(
     config: &SourceConfig,
     filter_config: &FilterConfig,
     account_write_queue_sender: async_channel::Sender<AccountWrite>,
+    metdata_write_queue_sender: Option<async_channel::Sender<FeedMetadata>>,
     slot_queue_sender: async_channel::Sender<SlotUpdate>,
     metrics_sender: Metrics,
     exit: Arc<AtomicBool>,
@@ -504,6 +506,14 @@ pub async fn process_events(
     let mut metric_snapshot_account_writes =
         metrics_sender.register_u64("grpc_snapshot_account_writes".into(), MetricType::Counter);
 
+    let metadata_sender = |msg| {
+        if let Some(sender) = &metdata_write_queue_sender {
+            sender.send_blocking(msg)
+        } else {
+            Ok(())
+        }
+    };
+
     loop {
         if exit.load(Ordering::Relaxed) {
             warn!("shutting down grpc_plugin_source...");
@@ -593,6 +603,10 @@ pub async fn process_events(
             Message::Snapshot(update) => {
                 metric_snapshots.increment();
                 info!("processing snapshot...");
+                if let Err(e) = metadata_sender(FeedMetadata::SnapshotStart) {
+                    warn!("failed to send feed matadata event: {}", e);
+                }
+
                 for account in update.accounts.iter() {
                     metric_snapshot_account_writes.increment();
                     metric_account_queue.set(account_write_queue_sender.len() as u64);
@@ -607,10 +621,20 @@ pub async fn process_events(
                                 .await
                                 .expect("send success");
                         }
-                        (key, None) => warn!("account not found {}", key),
+                        (key, None) => {
+                            warn!("account not found {}", key);
+                            let pubkey = Pubkey::from_str(key).unwrap();
+                            if let Err(e) = metadata_sender(FeedMetadata::InvalidAccount(pubkey)) {
+                                warn!("failed to send feed matadata event: {}", e);
                             }
                         }
+                    }
+                }
+
                 info!("processing snapshot done");
+                if let Err(e) = metadata_sender(FeedMetadata::SnapshotEnd) {
+                    warn!("failed to send feed matadata event: {}", e);
+                }
             }
         }
     }

connector/src/lib.rs

@@ -28,6 +28,12 @@ impl<T, E: std::fmt::Debug> AnyhowWrap for Result<T, E> {
     }
 }
 
+pub enum FeedMetadata {
+    InvalidAccount(Pubkey),
+    SnapshotStart,
+    SnapshotEnd,
+}
+
 #[derive(Clone, PartialEq, Debug)]
 pub struct AccountWrite {
     pub pubkey: Pubkey,