[Placement Group] Support Placement Group state table. (#10090)

* Done.

* Addressed code review.

* Linting.

* Fix lint.

* Fix lint.

* Fix a test.

* Lint.

* Add a lint sleep to test.

* Fix the lint issue.

* Fixed doc build error.

src/ray/core_worker/core_worker.cc

@@ -1396,7 +1396,6 @@ Status CoreWorker::KillActor(const ActorID &actor_id, bool force_kill, bool no_r
   return Status::OK();
 }
 
-// SANG-TODO
 Status CoreWorker::KillActorLocalMode(const ActorID &actor_id) {
   // KillActor doesn't do anything in local mode. We only remove named actor entry if
   // exists.

src/ray/gcs/accessor.h

@@ -737,10 +737,19 @@ class PlacementGroupInfoAccessor {
   ///
   /// \param placement_group_spec The specification for the placement group creation task.
   /// \param callback Callback that will be called after the placement group info is
-  /// written to GCS. \return Status
+  /// written to GCS.
+  /// \return Status.
   virtual Status AsyncCreatePlacementGroup(
       const PlacementGroupSpecification &placement_group_spec) = 0;
 
+  /// Get a placement group data from GCS asynchronously.
+  ///
+  /// \param placement_group_id The id of a placement group to obtain from GCS.
+  /// \return Status.
+  virtual Status AsyncGet(
+      const PlacementGroupID &placement_group_id,
+      const OptionalItemCallback<rpc::PlacementGroupTableData> &callback) = 0;
+
  protected:
   PlacementGroupInfoAccessor() = default;
 };

src/ray/gcs/gcs_client/global_state_accessor.cc

@@ -232,5 +232,16 @@ bool GlobalStateAccessor::AddWorkerInfo(const std::string &serialized_string) {
   return true;
 }
 
+std::unique_ptr<std::string> GlobalStateAccessor::GetPlacementGroupInfo(
+    const PlacementGroupID &placement_group_id) {
+  std::unique_ptr<std::string> placement_group_table_data;
+  std::promise<bool> promise;
+  RAY_CHECK_OK(gcs_client_->PlacementGroups().AsyncGet(
+      placement_group_id, TransformForOptionalItemCallback<rpc::PlacementGroupTableData>(
+                              placement_group_table_data, promise)));
+  promise.get_future().get();
+  return placement_group_table_data;
+}
+
 }  // namespace gcs
 }  // namespace ray

src/ray/gcs/gcs_client/global_state_accessor.h

@@ -137,6 +137,15 @@ class GlobalStateAccessor {
   /// \return Is operation success.
   bool AddWorkerInfo(const std::string &serialized_string);
 
+  /// Get information of a placement group from GCS Service.
+  ///
+  /// \param placement_group The ID of placement group to look up in the GCS Service.
+  /// \return Placement group info. To support multi-language, we serialize each
+  /// PlacementGroupTableData and return the serialized string. Where used, it needs to be
+  /// deserialized with protobuf function.
+  std::unique_ptr<std::string> GetPlacementGroupInfo(
+      const PlacementGroupID &placement_group_id);
+
  private:
   /// MultiItem transformation helper in template style.
   ///

src/ray/gcs/gcs_client/service_based_accessor.cc

@@ -1462,5 +1462,26 @@ Status ServiceBasedPlacementGroupInfoAccessor::AsyncCreatePlacementGroup(
   return Status::OK();
 }
 
+Status ServiceBasedPlacementGroupInfoAccessor::AsyncGet(
+    const PlacementGroupID &placement_group_id,
+    const OptionalItemCallback<rpc::PlacementGroupTableData> &callback) {
+  RAY_LOG(DEBUG) << "Getting placement group info, placement group id = "
+                 << placement_group_id;
+  rpc::GetPlacementGroupRequest request;
+  request.set_placement_group_id(placement_group_id.Binary());
+  client_impl_->GetGcsRpcClient().GetPlacementGroup(
+      request, [placement_group_id, callback](const Status &status,
+                                              const rpc::GetPlacementGroupReply &reply) {
+        if (reply.has_placement_group_table_data()) {
+          callback(status, reply.placement_group_table_data());
+        } else {
+          callback(status, boost::none);
+        }
+        RAY_LOG(DEBUG) << "Finished getting placement group info, placement group id = "
+                       << placement_group_id;
+      });
+  return Status::OK();
+}
+
 }  // namespace gcs
 }  // namespace ray

src/ray/gcs/gcs_client/service_based_accessor.h

@@ -446,6 +446,10 @@ class ServiceBasedPlacementGroupInfoAccessor : public PlacementGroupInfoAccessor
   Status AsyncCreatePlacementGroup(
       const PlacementGroupSpecification &placement_group_spec) override;
 
+  Status AsyncGet(
+      const PlacementGroupID &placement_group_id,
+      const OptionalItemCallback<rpc::PlacementGroupTableData> &callback) override;
+
  private:
   ServiceBasedGcsClient *client_impl_;
 };

src/ray/gcs/gcs_client/test/global_state_accessor_test.cc

@@ -269,6 +269,8 @@ TEST_F(GlobalStateAccessorTest, TestWorkerTable) {
   ASSERT_EQ(global_state_->GetAllWorkerInfo().size(), 2);
 }
 
+// TODO(sang): Add tests after adding asyncAdd
+
 }  // namespace ray
 
 int main(int argc, char **argv) {

src/ray/gcs/gcs_client/test/service_based_gcs_client_test.cc

@@ -1173,6 +1173,8 @@ TEST_F(ServiceBasedGcsClientTest, TestMultiThreadSubAndUnsub) {
   }
 }
 
+// TODO(sang): Add tests after adding asyncAdd
+
 }  // namespace ray
 
 int main(int argc, char **argv) {

src/ray/gcs/gcs_server/gcs_placement_group_manager.cc

@@ -174,6 +174,32 @@ void GcsPlacementGroupManager::HandleCreatePlacementGroup(
       }));
 }
 
+void GcsPlacementGroupManager::HandleGetPlacementGroup(
+    const rpc::GetPlacementGroupRequest &request, rpc::GetPlacementGroupReply *reply,
+    rpc::SendReplyCallback send_reply_callback) {
+  PlacementGroupID placement_group_id =
+      PlacementGroupID::FromBinary(request.placement_group_id());
+  RAY_LOG(DEBUG) << "Getting placement group info, placement group id = "
+                 << placement_group_id;
+
+  auto on_done = [placement_group_id, reply, send_reply_callback](
+                     const Status &status,
+                     const boost::optional<PlacementGroupTableData> &result) {
+    if (result) {
+      reply->mutable_placement_group_table_data()->CopyFrom(*result);
+    }
+    RAY_LOG(DEBUG) << "Finished getting placement group info, placement group id = "
+                   << placement_group_id;
+    GCS_RPC_SEND_REPLY(send_reply_callback, reply, Status::OK());
+  };
+
+  Status status =
+      gcs_table_storage_->PlacementGroupTable().Get(placement_group_id, on_done);
+  if (!status.ok()) {
+    on_done(status, boost::none);
+  }
+}
+
 void GcsPlacementGroupManager::RetryCreatingPlacementGroup() {
   execute_after(io_context_, [this] { SchedulePendingPlacementGroups(); },
                 RayConfig::instance().gcs_create_placement_group_retry_interval_ms());

src/ray/gcs/gcs_server/gcs_placement_group_manager.h

@@ -107,6 +107,10 @@ class GcsPlacementGroupManager : public rpc::PlacementGroupInfoHandler {
                                   rpc::CreatePlacementGroupReply *reply,
                                   rpc::SendReplyCallback send_reply_callback) override;
 
+  void HandleGetPlacementGroup(const rpc::GetPlacementGroupRequest &request,
+                               rpc::GetPlacementGroupReply *reply,
+                               rpc::SendReplyCallback send_reply_callback) override;
+
   /// Register placement_group asynchronously.
   ///
   /// \param request Contains the meta info to create the placement_group.

src/ray/gcs/gcs_server/test/gcs_server_rpc_test.cc

@@ -771,6 +771,8 @@ TEST_F(GcsServerTest, TestWorkerInfo) {
               worker_data->worker_address().worker_id());
 }
 
+// TODO(sang): Add tests after adding asyncAdd
+
 }  // namespace ray
 
 int main(int argc, char **argv) {

src/ray/gcs/redis_accessor.cc

@@ -833,6 +833,12 @@ Status RedisPlacementGroupInfoAccessor::AsyncCreatePlacementGroup(
   return Status::Invalid("Not implemented");
 }
 
+Status RedisPlacementGroupInfoAccessor::AsyncGet(
+    const PlacementGroupID &placement_group_id,
+    const OptionalItemCallback<rpc::PlacementGroupTableData> &callback) {
+  return Status::Invalid("Not implemented");
+}
+
 }  // namespace gcs
 
 }  // namespace ray

src/ray/gcs/redis_accessor.h

@@ -478,6 +478,10 @@ class RedisPlacementGroupInfoAccessor : public PlacementGroupInfoAccessor {
 
   Status AsyncCreatePlacementGroup(
       const PlacementGroupSpecification &placement_group_spec) override;
+
+  Status AsyncGet(
+      const PlacementGroupID &placement_group_id,
+      const OptionalItemCallback<rpc::PlacementGroupTableData> &callback) override;
 };
 
 }  // namespace gcs

src/ray/protobuf/gcs_service.proto

@@ -166,9 +166,11 @@ service ActorInfoGcsService {
 
 // Service for placement group info access.
 service PlacementGroupInfoGcsService {
-  // Create placement group via gcs service
+  // Create placement group via gcs service.
   rpc CreatePlacementGroup(CreatePlacementGroupRequest)
       returns (CreatePlacementGroupReply);
+  // Get placement group information via gcs service.
+  rpc GetPlacementGroup(GetPlacementGroupRequest) returns (GetPlacementGroupReply);
 }
 
 message RegisterNodeRequest {
@@ -497,6 +499,15 @@ message CreatePlacementGroupReply {
   GcsStatus status = 1;
 }
 
+message GetPlacementGroupRequest {
+  bytes placement_group_id = 1;
+}
+
+message GetPlacementGroupReply {
+  GcsStatus status = 1;
+  PlacementGroupTableData placement_group_table_data = 2;
+}
+
 enum GcsServiceFailureType {
   RPC_DISCONNECT = 0;
   GCS_SERVER_RESTART = 1;

src/ray/rpc/gcs_server/gcs_rpc_client.h

@@ -251,6 +251,10 @@ class GcsRpcClient {
   VOID_GCS_RPC_CLIENT_METHOD(PlacementGroupInfoGcsService, CreatePlacementGroup,
                              placement_group_info_grpc_client_, )
 
+  /// Get placement group via GCS Service.
+  VOID_GCS_RPC_CLIENT_METHOD(PlacementGroupInfoGcsService, GetPlacementGroup,
+                             placement_group_info_grpc_client_, )
+
  private:
   std::function<void(GcsServiceFailureType)> gcs_service_failure_detected_;
 

src/ray/rpc/gcs_server/gcs_rpc_server.h

@@ -456,6 +456,10 @@ class PlacementGroupInfoGcsServiceHandler {
   virtual void HandleCreatePlacementGroup(const CreatePlacementGroupRequest &request,
                                           CreatePlacementGroupReply *reply,
                                           SendReplyCallback send_reply_callback) = 0;
+
+  virtual void HandleGetPlacementGroup(const GetPlacementGroupRequest &request,
+                                       GetPlacementGroupReply *reply,
+                                       SendReplyCallback send_reply_callback) = 0;
 };
 
 /// The `GrpcService` for `PlacementGroupInfoGcsService`.
@@ -475,6 +479,7 @@ class PlacementGroupInfoGrpcService : public GrpcService {
       const std::unique_ptr<grpc::ServerCompletionQueue> &cq,
       std::vector<std::unique_ptr<ServerCallFactory>> *server_call_factories) override {
     PLACEMENT_GROUP_INFO_SERVICE_RPC_HANDLER(CreatePlacementGroup);
+    PLACEMENT_GROUP_INFO_SERVICE_RPC_HANDLER(GetPlacementGroup);
   }
 
  private: