diff options
Diffstat (limited to 'src/mongo/db/repl/freshness_checker.h')
| -rw-r--r-- | src/mongo/db/repl/freshness_checker.h | 225 |
1 files changed, 113 insertions, 112 deletions
diff --git a/src/mongo/db/repl/freshness_checker.h b/src/mongo/db/repl/freshness_checker.h index 188e67bd953..11515bfc0ad 100644 --- a/src/mongo/db/repl/freshness_checker.h +++ b/src/mongo/db/repl/freshness_checker.h @@ -38,127 +38,128 @@ namespace mongo { - class Status; +class Status; namespace repl { - class ReplicaSetConfig; - class ScatterGatherRunner; +class ReplicaSetConfig; +class ScatterGatherRunner; - class FreshnessChecker { - MONGO_DISALLOW_COPYING(FreshnessChecker); +class FreshnessChecker { + MONGO_DISALLOW_COPYING(FreshnessChecker); + +public: + enum ElectionAbortReason { + None = 0, + FresherNodeFound, // Freshness check found fresher node + FreshnessTie, // Freshness check resulted in one or more nodes with our lastAppliedOpTime + QuorumUnavailable, // Not enough up voters + QuorumUnreachable // Too many failed voter responses + }; + + class Algorithm : public ScatterGatherAlgorithm { public: - enum ElectionAbortReason { - None = 0, - FresherNodeFound, // Freshness check found fresher node - FreshnessTie, // Freshness check resulted in one or more nodes with our lastAppliedOpTime - QuorumUnavailable, // Not enough up voters - QuorumUnreachable // Too many failed voter responses - }; - - class Algorithm : public ScatterGatherAlgorithm { - public: - Algorithm(Timestamp lastOpTimeApplied, - const ReplicaSetConfig& rsConfig, - int selfIndex, - const std::vector<HostAndPort>& targets); - virtual ~Algorithm(); - virtual std::vector<RemoteCommandRequest> getRequests() const; - virtual void processResponse( - const RemoteCommandRequest& request, - const ResponseStatus& response); - virtual bool hasReceivedSufficientResponses() const; - ElectionAbortReason shouldAbortElection() const; - - private: - // Returns true if the number of failed votes is over _losableVotes() - bool hadTooManyFailedVoterResponses() const; - - // Returns true if the member, by host and port, has a vote. - bool _isVotingMember(const HostAndPort host) const; - - // Number of responses received so far. - int _responsesProcessed; - - // Number of failed voter responses so far. - int _failedVoterResponses; - - // Last Timestamp applied by the caller; used in the Fresh command - const Timestamp _lastOpTimeApplied; - - // Config to use for this check - const ReplicaSetConfig _rsConfig; - - // Our index position in _rsConfig - const int _selfIndex; - - // The UP members we are checking - const std::vector<HostAndPort> _targets; - - // Number of voting targets - int _votingTargets; - - // Number of voting nodes which can error - int _losableVoters; - - // 1 if I have a vote, otherwise 0 - int _myVote; - - // Reason to abort, start with None - ElectionAbortReason _abortReason; - - }; - - FreshnessChecker(); - virtual ~FreshnessChecker(); - - /** - * Begins the process of sending replSetFresh commands to all non-DOWN nodes - * in currentConfig, with the intention of determining whether the current node - * is freshest. - * evh can be used to schedule a callback when the process is complete. - * This function must be run in the executor, as it must be synchronous with the command - * callbacks that it schedules. - * If this function returns Status::OK(), evh is then guaranteed to be signaled. - **/ - StatusWith<ReplicationExecutor::EventHandle> start( - ReplicationExecutor* executor, - const Timestamp& lastOpTimeApplied, - const ReplicaSetConfig& currentConfig, - int selfIndex, - const std::vector<HostAndPort>& targets, - const stdx::function<void ()>& onCompletion = stdx::function<void ()>()); - - /** - * Informs the freshness checker to cancel further processing. The "executor" - * argument must point to the same executor passed to "start()". - * - * Like start(), this method must run in the executor context. - */ - void cancel(ReplicationExecutor* executor); - - /** - * Returns true if cancel() was called on this instance. - */ - bool isCanceled() const { return _isCanceled; } - - /** - * 'None' if the election should continue, otherwise the reason to abort - */ + Algorithm(Timestamp lastOpTimeApplied, + const ReplicaSetConfig& rsConfig, + int selfIndex, + const std::vector<HostAndPort>& targets); + virtual ~Algorithm(); + virtual std::vector<RemoteCommandRequest> getRequests() const; + virtual void processResponse(const RemoteCommandRequest& request, + const ResponseStatus& response); + virtual bool hasReceivedSufficientResponses() const; ElectionAbortReason shouldAbortElection() const; - /** - * Returns the config version supplied in the config when start() was called. - * Useful for determining if the the config version has changed. - */ - long long getOriginalConfigVersion() const; - private: - std::unique_ptr<Algorithm> _algorithm; - std::unique_ptr<ScatterGatherRunner> _runner; - long long _originalConfigVersion; - bool _isCanceled; + // Returns true if the number of failed votes is over _losableVotes() + bool hadTooManyFailedVoterResponses() const; + + // Returns true if the member, by host and port, has a vote. + bool _isVotingMember(const HostAndPort host) const; + + // Number of responses received so far. + int _responsesProcessed; + + // Number of failed voter responses so far. + int _failedVoterResponses; + + // Last Timestamp applied by the caller; used in the Fresh command + const Timestamp _lastOpTimeApplied; + + // Config to use for this check + const ReplicaSetConfig _rsConfig; + + // Our index position in _rsConfig + const int _selfIndex; + + // The UP members we are checking + const std::vector<HostAndPort> _targets; + + // Number of voting targets + int _votingTargets; + + // Number of voting nodes which can error + int _losableVoters; + + // 1 if I have a vote, otherwise 0 + int _myVote; + + // Reason to abort, start with None + ElectionAbortReason _abortReason; }; + FreshnessChecker(); + virtual ~FreshnessChecker(); + + /** + * Begins the process of sending replSetFresh commands to all non-DOWN nodes + * in currentConfig, with the intention of determining whether the current node + * is freshest. + * evh can be used to schedule a callback when the process is complete. + * This function must be run in the executor, as it must be synchronous with the command + * callbacks that it schedules. + * If this function returns Status::OK(), evh is then guaranteed to be signaled. + **/ + StatusWith<ReplicationExecutor::EventHandle> start( + ReplicationExecutor* executor, + const Timestamp& lastOpTimeApplied, + const ReplicaSetConfig& currentConfig, + int selfIndex, + const std::vector<HostAndPort>& targets, + const stdx::function<void()>& onCompletion = stdx::function<void()>()); + + /** + * Informs the freshness checker to cancel further processing. The "executor" + * argument must point to the same executor passed to "start()". + * + * Like start(), this method must run in the executor context. + */ + void cancel(ReplicationExecutor* executor); + + /** + * Returns true if cancel() was called on this instance. + */ + bool isCanceled() const { + return _isCanceled; + } + + /** + * 'None' if the election should continue, otherwise the reason to abort + */ + ElectionAbortReason shouldAbortElection() const; + + /** + * Returns the config version supplied in the config when start() was called. + * Useful for determining if the the config version has changed. + */ + long long getOriginalConfigVersion() const; + +private: + std::unique_ptr<Algorithm> _algorithm; + std::unique_ptr<ScatterGatherRunner> _runner; + long long _originalConfigVersion; + bool _isCanceled; +}; + } // namespace repl } // namespace mongo |