| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef __MESOS_V1_SCHEDULER_HPP__ |
| #define __MESOS_V1_SCHEDULER_HPP__ |
| |
| #include <functional> |
| #include <memory> |
| #include <queue> |
| #include <string> |
| |
| #include <mesos/http.hpp> |
| |
| #include <mesos/v1/mesos.hpp> |
| |
| #include <mesos/v1/scheduler/scheduler.hpp> |
| |
| #include <process/future.hpp> |
| |
| #include <stout/option.hpp> |
| |
| namespace mesos { |
| |
| namespace master { |
| namespace detector { |
| class MasterDetector; |
| } // namespace detector { |
| } // namespace master { |
| |
| namespace v1 { |
| namespace scheduler { |
| |
| class MesosProcess; // Forward declaration. |
| |
| // Abstract interface for connecting a scheduler to Mesos. |
| class MesosBase |
| { |
| public: |
| // Empty virtual destructor (necessary to instantiate subclasses). |
| virtual ~MesosBase() {} |
| virtual void send(const Call& call) = 0; |
| virtual process::Future<APIResult> call(const Call& callMessage) = 0; |
| virtual void reconnect() = 0; |
| }; |
| |
| |
| // Concrete implementation that connects a scheduler to a Mesos master. |
| // Abstracts master detection (connection and disconnection). |
| // |
| // Expects three callbacks, 'connected', 'disconnected', and |
| // 'received' which will get invoked _serially_ when it's determined |
| // that we've connected (i.e., detected master), disconnected |
| // (i.e, detected no master), or received events from the master. |
| // The library reconnects with the master upon a disconnection. |
| // |
| // NOTE: All calls and events are dropped while disconnected. |
| class Mesos : public MesosBase |
| { |
| public: |
| // The credential will be used for authenticating with the master. Currently, |
| // only HTTP basic authentication is supported. |
| Mesos(const std::string& master, |
| ContentType contentType, |
| const std::function<void()>& connected, |
| const std::function<void()>& disconnected, |
| const std::function<void(const std::queue<Event>&)>& received, |
| const Option<Credential>& credential); |
| |
| // Delete copy constructor. |
| Mesos(const Mesos& other) = delete; |
| |
| // Delete assignment operator. |
| Mesos& operator=(const Mesos& other) = delete; |
| |
| ~Mesos() override; |
| |
| // Attempts to send a call to the master. |
| // |
| // The scheduler should only invoke this method once it has received the |
| // 'connected' callback. Otherwise, all calls would be dropped while |
| // disconnected. |
| // |
| // Some local validation of calls is performed which may generate |
| // events without ever being sent to the master. This includes when |
| // calls are sent but no master is currently detected (i.e., we're |
| // disconnected). |
| void send(const Call& call) override; |
| |
| // Attempts to send a call to the master, returning the response. |
| // |
| // The scheduler should only invoke this method once it has received the |
| // 'connected' callback. Otherwise, a `Failure` will be returned. |
| // |
| // Some local validation of calls is performed, and the request will not be |
| // sent to the master if the validation fails. |
| // |
| // A `Failure` will be returned on validation failures or if an error happens |
| // when sending the request to the master, e.g., a master disconnection, or a |
| // deserialization error. |
| // |
| // If it was possible to receive a response from the server, the returned |
| // object will contain the HTTP response status code. |
| // |
| // There are three cases to consider depending on the HTTP response status |
| // code: |
| // |
| // (1) '202 ACCEPTED': Indicates the call was accepted for processing and |
| // neither `APIResult::response` nor `APIResult::error` will be set. |
| // |
| // (2) '200 OK': Indicates the call completed successfully. |
| // `APIResult::response` will be set if the `scheduler::Call::Type` |
| // has a corresponding `scheduler::Response::Type`, `APIResult::error` |
| // will not be set. |
| // |
| // (3) For all other HTTP status codes, the `APIResult::response` field will |
| // not be set and the `APIResult::error` field may be set to provide more |
| // information. |
| // |
| // Note: This method cannot be used to send `SUBSCRIBE` calls, use `send()` |
| // instead. |
| process::Future<APIResult> call(const Call& callMessage) override; |
| |
| // Force a reconnection with the master. |
| // |
| // In the case of a one-way network partition, the connection between the |
| // scheduler and master might not necessarily break. If the scheduler detects |
| // a partition, due to lack of `HEARTBEAT` events (e.g., 5) within a time |
| // window, it can explicitly ask the library to force a reconnection with |
| // the master. |
| // |
| // This call would be ignored if the scheduler is already disconnected with |
| // the master (e.g., no new master has been elected). Otherwise, the scheduler |
| // would get a 'disconnected' callback followed by a 'connected' callback. |
| void reconnect() override; |
| |
| protected: |
| // NOTE: This constructor is used for testing. |
| Mesos( |
| const std::string& master, |
| ContentType contentType, |
| const std::function<void()>& connected, |
| const std::function<void()>& disconnected, |
| const std::function<void(const std::queue<Event>&)>& received, |
| const Option<Credential>& credential, |
| const Option<std::shared_ptr<mesos::master::detector::MasterDetector>>& |
| detector); |
| |
| // Stops the library so that: |
| // - No more calls can be sent to the master. |
| // - No more callbacks can be made to the scheduler. In some cases, there |
| // may be one additional callback if the library was in the middle of |
| // processing an event. |
| // |
| // NOTE: This is used for testing. |
| virtual void stop(); |
| |
| private: |
| MesosProcess* process; |
| }; |
| |
| } // namespace scheduler { |
| } // namespace v1 { |
| } // namespace mesos { |
| |
| #endif // __MESOS_V1_SCHEDULER_HPP__ |