Don't put entire actor registry in debug string since it's too long (#3395)

src/ray/raylet/actor_registration.cc

@@ -10,7 +10,6 @@ namespace raylet {
 
 ActorRegistration::ActorRegistration(const ActorTableDataT &actor_table_data)
     : actor_table_data_(actor_table_data),
-      alive_(true),
       execution_dependency_(ObjectID::nil()),
       frontier_() {}
 
@@ -44,16 +43,7 @@ bool ActorRegistration::IsAlive() const {
   return actor_table_data_.state == ActorState::ALIVE;
 }
 
-std::string ActorRegistration::DebugString() const {
-  std::stringstream result;
-  if (alive_) {
-    result << "alive";
-  } else {
-    result << "dead";
-  }
-  result << ", num handles: " << frontier_.size();
-  return result.str();
-}
+int ActorRegistration::NumHandles() const { return frontier_.size(); }
 
 }  // namespace raylet
 

src/ray/raylet/actor_registration.h

@@ -94,17 +94,15 @@ class ActorRegistration {
   /// \return True if the local actor is alive and false if it is dead.
   bool IsAlive() const;
 
-  /// Returns debug string for class.
+  /// Returns num handles to this actor entry.
   ///
-  /// \return string.
-  std::string DebugString() const;
+  /// \return int.
+  int NumHandles() const;
 
  private:
   /// Information from the global actor table about this actor, including the
   /// node manager location.
   ActorTableDataT actor_table_data_;
-  /// True if the actor is alive and false otherwise.
-  bool alive_;
   /// The object representing the state following the actor's most recently
   /// executed task. The next task to execute on the actor should be marked as
   /// execution-dependent on this object.

src/ray/raylet/node_manager.cc

@@ -1764,14 +1764,27 @@ std::string NodeManager::DebugString() const {
   result << "\n" << reconstruction_policy_.DebugString();
   result << "\n" << task_dependency_manager_.DebugString();
   result << "\n" << lineage_cache_.DebugString();
+  result << "\nActorRegistry:";
+  int live_actors = 0;
+  int dead_actors = 0;
+  int max_num_handles = 0;
+  for (auto &pair : actor_registry_) {
+    if (pair.second.IsAlive()) {
+      live_actors += 1;
+    } else {
+      dead_actors += 1;
+    }
+    if (pair.second.NumHandles() > max_num_handles) {
+      max_num_handles = pair.second.NumHandles();
+    }
+  }
+  result << "\n- num live actors: " << live_actors;
+  result << "\n- num dead actors: " << dead_actors;
+  result << "\n- max num handles: " << max_num_handles;
   result << "\nRemoteConnections:";
   for (auto &pair : remote_server_connections_) {
     result << "\n" << pair.first.hex() << ": " << pair.second->DebugString();
   }
-  result << "\nActorRegistry:";
-  for (auto &pair : actor_registry_) {
-    result << "\n" << pair.first.hex() << ": " << pair.second.DebugString();
-  }
   result << "\nDebugString() time ms: " << (current_time_ms() - now_ms);
   return result.str();
 }