//////////////////////////////////////////////////////////////////////////////// /// DISCLAIMER /// /// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany /// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany /// /// Licensed 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. /// /// Copyright holder is ArangoDB GmbH, Cologne, Germany /// /// @author Kaveh Vahedipour //////////////////////////////////////////////////////////////////////////////// #ifndef ARANGOD_CONSENSUS_CONSTITUENT_H #define ARANGOD_CONSENSUS_CONSTITUENT_H 1 #include #include "AgencyCommon.h" #include "AgentConfiguration.h" #include "NotifierThread.h" #include "Basics/Common.h" #include "Basics/Thread.h" #include "Basics/ConditionVariable.h" struct TRI_vocbase_t; namespace arangodb { namespace aql { class QueryRegistry; } namespace consensus { class Agent; /// @brief RAFT leader election class Constituent : public arangodb::Thread { public: /// @brief Distribution type typedef std::uniform_real_distribution dist_t; /// @brief Default ctor Constituent(); /// @brief Clean up and exit election virtual ~Constituent(); /// @brief Configure with agent's configuration void configure(Agent*); /// @brief Current term term_t term() const; /// @brief Get current role role_t role() const; /// @brief Are we leading? bool leading() const; /// @brief Are we following? bool following() const; /// @brief Are we running for leadership? bool running() const; /// @brief Called by REST handler bool vote(term_t, arangodb::consensus::id_t, index_t, term_t); /// @brief My daily business void run() override final; /// @brief Who is leading arangodb::consensus::id_t leaderID () const; /// @brief Configuration config_t const& config () const; /// @brief Become follower void follow(term_t); /// @brief Agency size size_t size() const; /// @brief Orderly shutdown of thread void beginShutdown() override; bool start(TRI_vocbase_t* vocbase, aql::QueryRegistry*); private: /// @brief set term to new term void term (term_t); /// @brief Agency endpoints std::vector const& endpoints() const; /// @brief Endpoint of agent with id std::string const& endpoint(arangodb::consensus::id_t) const; /// @brief Run for leadership void candidate(); /// @brief Become leader void lead(); /// @brief Call for vote (by leader or candidates after timeout) void callElection(); /// @brief Count my votes void countVotes(); /// @brief Wait for sync bool waitForSync () const; /// @brief Notify everyone, that we are good to go. /// This is the task of the last process starting up. /// Will be taken care of by gossip void notifyAll(); /// @brief Sleep for how long duration_t sleepFor(double, double); TRI_vocbase_t* _vocbase; aql::QueryRegistry* _queryRegistry; term_t _term; /**< @brief term number */ std::atomic _cast; /**< @brief cast a vote this term */ std::atomic _state; /**< @brief State (follower, candidate, leader)*/ arangodb::consensus::id_t _leaderID; /**< @brief Current leader */ arangodb::consensus::id_t _id; /**< @brief My own id */ constituency_t _constituency; /**< @brief List of consituents */ std::mt19937 _gen; /**< @brief Random number generator */ role_t _role; /**< @brief My role */ Agent* _agent; /**< @brief My boss */ arangodb::consensus::id_t _votedFor; std::unique_ptr _notifier; arangodb::basics::ConditionVariable _cv; // agency callbacks mutable arangodb::Mutex _castLock; }; }} #endif