feat(Core): gracefully shutdown router/scheduler if Redis is unavailable (#891)

Co-authored-by: prajjwal kumar <prajjwal.kumar@prajjwalkumar-DWKH9NPY4R.local>
Co-authored-by: Nishant Joshi <nishant.joshi@juspay.in>
Co-authored-by: Arun Raj M <jarnura47@gmail.com>

crates/redis_interface/src/lib.rs

@@ -138,12 +138,18 @@ impl RedisConnectionPool {
             };
         }
     }
-    pub async fn on_error(&self) {
+
+    pub async fn on_error(&self, tx: tokio::sync::oneshot::Sender<()>) {
         while let Ok(redis_error) = self.pool.on_error().recv().await {
             logger::error!(?redis_error, "Redis protocol or connection error");
+            logger::error!("current state: {:#?}", self.pool.state());
             if self.pool.state() == fred::types::ClientState::Disconnected {
+                if tx.send(()).is_err() {
+                    logger::error!("The redis shutdown signal sender failed to signal");
+                }
                 self.is_redis_available
                     .store(false, atomic::Ordering::SeqCst);
+                break;
             }
         }
     }