mirror of https://gitee.com/bigwinds/arangodb
152 lines
3.7 KiB
C++
152 lines
3.7 KiB
C++
////////////////////////////////////////////////////////////////////////////////
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/// DISCLAIMER
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///
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/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
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/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
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///
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/// Licensed under the Apache License, Version 2.0 (the "License");
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/// you may not use this file except in compliance with the License.
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/// You may obtain a copy of the License at
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///
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/// http://www.apache.org/licenses/LICENSE-2.0
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///
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/// Unless required by applicable law or agreed to in writing, software
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/// distributed under the License is distributed on an "AS IS" BASIS,
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/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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/// See the License for the specific language governing permissions and
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/// limitations under the License.
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///
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/// Copyright holder is ArangoDB GmbH, Cologne, Germany
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///
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/// @author Kaveh Vahedipour
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////////////////////////////////////////////////////////////////////////////////
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#ifndef ARANGOD_CONSENSUS_CONSTITUENT_H
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#define ARANGOD_CONSENSUS_CONSTITUENT_H 1
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#include "AgencyCommon.h"
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#include "AgentConfiguration.h"
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#include "Basics/Common.h"
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#include "Basics/Thread.h"
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#include "Basics/ConditionVariable.h"
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struct TRI_vocbase_t;
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namespace arangodb {
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namespace aql {
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class QueryRegistry;
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}
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namespace consensus {
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class Agent;
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/// @brief RAFT leader election
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class Constituent : public arangodb::Thread {
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public:
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/// @brief Default ctor
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Constituent();
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/// @brief Clean up and exit election
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virtual ~Constituent();
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/// @brief Configure with agent's configuration
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void configure(Agent*);
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/// @brief Current term
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term_t term() const;
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/// @brief Get current role
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role_t role() const;
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/// @brief Are we leading?
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bool leading() const;
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/// @brief Are we following?
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bool following() const;
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/// @brief Are we running for leadership?
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bool running() const;
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/// @brief Called by REST handler
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bool vote(term_t, std::string, index_t, term_t,
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bool appendEntries = false);
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/// @brief My daily business
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void run() override final;
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/// @brief Who is leading
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std::string leaderID() const;
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/// @brief Configuration
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config_t const& config() const;
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/// @brief Become follower
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void follow(term_t);
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/// @brief Agency size
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size_t size() const;
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/// @brief Orderly shutdown of thread
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void beginShutdown() override;
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bool start(TRI_vocbase_t* vocbase, aql::QueryRegistry*);
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friend class Agent;
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private:
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/// @brief update leaderId and term if inactive
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void update(std::string const&, term_t);
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/// @brief set term to new term
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void term(term_t);
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/// @brief Agency endpoints
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std::vector<std::string> const& endpoints() const;
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/// @brief Endpoint of agent with id
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std::string endpoint(std::string) const;
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/// @brief Run for leadership
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void candidate();
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/// @brief Become leader
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void lead(std::map<std::string,bool> const& =
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std::map<std::string,bool>());
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/// @brief Call for vote (by leader or candidates after timeout)
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void callElection();
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/// @brief Count my votes
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void countVotes();
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/// @brief Wait for sync
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bool waitForSync() const;
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/// @brief Sleep for how long
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duration_t sleepFor(double, double);
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TRI_vocbase_t* _vocbase;
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aql::QueryRegistry* _queryRegistry;
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term_t _term; /**< @brief term number */
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std::atomic<bool> _cast; /**< @brief cast a vote this term */
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std::string _leaderID; /**< @brief Current leader */
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std::string _id; /**< @brief My own id */
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role_t _role; /**< @brief My role */
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Agent* _agent; /**< @brief My boss */
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std::string _votedFor;
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arangodb::basics::ConditionVariable _cv; // agency callbacks
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mutable arangodb::Mutex _castLock;
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};
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}
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}
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#endif
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