Add logging to the new verify authority daemon.

src/verify_authority.rs

@@ -301,11 +301,18 @@ impl<Command: 'static + Send> Raft<Command> {
         let unparker = parker.unparker().clone();
         self.verify_authority_daemon.unparker.replace(unparker);
 
+        let me = self.me.clone();
         let keep_running = self.keep_running.clone();
+        let daemon_env = self.daemon_env.clone();
         let this_daemon = self.verify_authority_daemon.clone();
         let rf = self.inner_state.clone();
+        let stop_wait_group = self.stop_wait_group.clone();
 
         let join_handle = std::thread::spawn(move || {
+            // Note: do not change this to `let _ = ...`.
+            let _guard = daemon_env.for_scope();
+
+            log::info!("{:?} verify authority daemon running ...", me);
             while keep_running.load(Ordering::Acquire) {
                 parker.park_timeout(Self::BEAT_RECORDING_MAX_PAUSE);
                 let (current_term, commit_index, sentinel) = {
@@ -318,6 +325,9 @@ impl<Command: 'static + Send> Raft<Command> {
                     sentinel,
                 );
             }
+            log::info!("{:?} verify authority daemon done.", me);
+
+            drop(stop_wait_group);
         });
         self.daemon_env
             .watch_daemon(Daemon::VerifyAuthority, join_handle);