Documentation ¶
Index ¶
- Constants
- Variables
- func LogLevel() int
- func RegisterCommand(command Command)
- func SetLogLevel(level int)
- type AppendEntriesRequest
- type AppendEntriesResponse
- type Command
- type CommandEncoder
- type Config
- type DefaultJoinCommand
- type DefaultLeaveCommand
- type HTTPMuxer
- type HTTPTransporter
- func (t *HTTPTransporter) AppendEntriesPath() string
- func (t *HTTPTransporter) Install(server Server, mux HTTPMuxer)
- func (t *HTTPTransporter) Prefix() string
- func (t *HTTPTransporter) RequestVotePath() string
- func (t *HTTPTransporter) SendAppendEntriesRequest(server Server, peer *Peer, req *AppendEntriesRequest) *AppendEntriesResponse
- func (t *HTTPTransporter) SendSnapshotRecoveryRequest(server Server, peer *Peer, req *SnapshotRecoveryRequest) *SnapshotRecoveryResponse
- func (t *HTTPTransporter) SendSnapshotRequest(server Server, peer *Peer, req *SnapshotRequest) *SnapshotResponse
- func (t *HTTPTransporter) SendVoteRequest(server Server, peer *Peer, req *RequestVoteRequest) *RequestVoteResponse
- type JoinCommand
- type LeaveCommand
- type Log
- type LogEntry
- type NOPCommand
- type Peer
- type RequestVoteRequest
- type RequestVoteResponse
- type Server
- type Snapshot
- type SnapshotRecoveryRequest
- type SnapshotRecoveryResponse
- type SnapshotRequest
- type SnapshotResponse
- type StateMachine
- type Transporter
Constants ¶
const ( Debug = 1 Trace = 2 )
const ( Stopped = "stopped" Follower = "follower" Candidate = "candidate" Leader = "leader" Snapshotting = "snapshotting" )
const ( MaxLogEntriesPerRequest = 2000 NumberOfLogEntriesAfterSnapshot = 200 )
const ( DefaultHeartbeatTimeout = 50 * time.Millisecond DefaultElectionTimeout = 150 * time.Millisecond )
const ( STOPPED = iota READY RUNNING )
Variables ¶
var CommandTimeoutError = errors.New("raft: Command timeout")
var DuplicatePeerError = errors.New("raft.Server: Duplicate peer")
var NotLeaderError = errors.New("raft.Server: Not current leader")
Functions ¶
func RegisterCommand ¶
func RegisterCommand(command Command)
Registers a command by storing a reference to an instance of it.
func SetLogLevel ¶
func SetLogLevel(level int)
Types ¶
type AppendEntriesRequest ¶
type AppendEntriesRequest struct { Term uint64 PrevLogIndex uint64 PrevLogTerm uint64 CommitIndex uint64 LeaderName string Entries []*LogEntry }
The request sent to a server to append entries to the log.
type AppendEntriesResponse ¶
type AppendEntriesResponse struct { Term uint64 // the current index of the server Index uint64 Success bool CommitIndex uint64 // contains filtered or unexported fields }
The response returned from a server appending entries to the log.
type CommandEncoder ¶
type DefaultJoinCommand ¶
type DefaultJoinCommand struct { Name string `json:"name"` ConnectionString string `json:"connectionString"` }
Join command
func (*DefaultJoinCommand) Apply ¶
func (c *DefaultJoinCommand) Apply(server Server) (interface{}, error)
func (*DefaultJoinCommand) CommandName ¶
func (c *DefaultJoinCommand) CommandName() string
The name of the Join command in the log
func (*DefaultJoinCommand) NodeName ¶
func (c *DefaultJoinCommand) NodeName() string
type DefaultLeaveCommand ¶
type DefaultLeaveCommand struct {
Name string `json:"name"`
}
Leave command
func (*DefaultLeaveCommand) Apply ¶
func (c *DefaultLeaveCommand) Apply(server Server) (interface{}, error)
func (*DefaultLeaveCommand) CommandName ¶
func (c *DefaultLeaveCommand) CommandName() string
The name of the Leave command in the log
func (*DefaultLeaveCommand) NodeName ¶
func (c *DefaultLeaveCommand) NodeName() string
type HTTPMuxer ¶
type HTTPMuxer interface {
HandleFunc(string, func(http.ResponseWriter, *http.Request))
}
type HTTPTransporter ¶
type HTTPTransporter struct { DisableKeepAlives bool // contains filtered or unexported fields }
An HTTPTransporter is a default transport layer used to communicate between multiple servers.
func NewHTTPTransporter ¶
func NewHTTPTransporter(prefix string) *HTTPTransporter
Creates a new HTTP transporter with the given path prefix.
func (*HTTPTransporter) AppendEntriesPath ¶
func (t *HTTPTransporter) AppendEntriesPath() string
Retrieves the AppendEntries path.
func (*HTTPTransporter) Install ¶
func (t *HTTPTransporter) Install(server Server, mux HTTPMuxer)
Applies Raft routes to an HTTP router for a given server.
func (*HTTPTransporter) Prefix ¶
func (t *HTTPTransporter) Prefix() string
Retrieves the path prefix used by the transporter.
func (*HTTPTransporter) RequestVotePath ¶
func (t *HTTPTransporter) RequestVotePath() string
Retrieves the RequestVote path.
func (*HTTPTransporter) SendAppendEntriesRequest ¶
func (t *HTTPTransporter) SendAppendEntriesRequest(server Server, peer *Peer, req *AppendEntriesRequest) *AppendEntriesResponse
Sends an AppendEntries RPC to a peer.
func (*HTTPTransporter) SendSnapshotRecoveryRequest ¶
func (t *HTTPTransporter) SendSnapshotRecoveryRequest(server Server, peer *Peer, req *SnapshotRecoveryRequest) *SnapshotRecoveryResponse
Sends a SnapshotRequest RPC to a peer.
func (*HTTPTransporter) SendSnapshotRequest ¶
func (t *HTTPTransporter) SendSnapshotRequest(server Server, peer *Peer, req *SnapshotRequest) *SnapshotResponse
Sends a SnapshotRequest RPC to a peer.
func (*HTTPTransporter) SendVoteRequest ¶
func (t *HTTPTransporter) SendVoteRequest(server Server, peer *Peer, req *RequestVoteRequest) *RequestVoteResponse
Sends a RequestVote RPC to a peer.
type JoinCommand ¶
type JoinCommand interface { CommandName() string Apply(server Server) (interface{}, error) NodeName() string }
Join command interface
type LeaveCommand ¶
type LeaveCommand interface { CommandName() string Apply(server Server) (interface{}, error) NodeName() string }
Leave command interface
type Log ¶
type Log struct { ApplyFunc func(Command) (interface{}, error) // contains filtered or unexported fields }
A log is a collection of log entries that are persisted to durable storage.
type LogEntry ¶
type LogEntry struct { Index uint64 Term uint64 CommandName string Command []byte Position int64 // position in the log file // contains filtered or unexported fields }
A log entry stores a single item in the log.
type NOPCommand ¶
type NOPCommand struct { }
NOP command
func (NOPCommand) Apply ¶
func (c NOPCommand) Apply(server Server) (interface{}, error)
func (NOPCommand) CommandName ¶
func (c NOPCommand) CommandName() string
The name of the NOP command in the log
type Peer ¶
type Peer struct { Name string `json:"name"` ConnectionString string `json:"connectionString"` // contains filtered or unexported fields }
A peer is a reference to another server involved in the consensus protocol.
type RequestVoteRequest ¶
type RequestVoteRequest struct { Term uint64 LastLogIndex uint64 LastLogTerm uint64 CandidateName string // contains filtered or unexported fields }
The request sent to a server to vote for a candidate to become a leader.
type RequestVoteResponse ¶
type RequestVoteResponse struct { Term uint64 VoteGranted bool // contains filtered or unexported fields }
The response returned from a server after a vote for a candidate to become a leader.
type Server ¶
type Server interface { Name() string Context() interface{} StateMachine() StateMachine Leader() string State() string Path() string LogPath() string SnapshotPath(lastIndex uint64, lastTerm uint64) string Term() uint64 CommitIndex() uint64 VotedFor() string MemberCount() int QuorumSize() int IsLogEmpty() bool LogEntries() []*LogEntry LastCommandName() string GetState() string ElectionTimeout() time.Duration SetElectionTimeout(duration time.Duration) HeartbeatTimeout() time.Duration SetHeartbeatTimeout(duration time.Duration) Transporter() Transporter SetTransporter(t Transporter) AppendEntries(req *AppendEntriesRequest) *AppendEntriesResponse RequestVote(req *RequestVoteRequest) *RequestVoteResponse RequestSnapshot(req *SnapshotRequest) *SnapshotResponse SnapshotRecoveryRequest(req *SnapshotRecoveryRequest) *SnapshotRecoveryResponse AddPeer(name string, connectiongString string) error RemovePeer(name string) error Peers() map[string]*Peer Start() error Stop() Running() bool Do(command Command) (interface{}, error) TakeSnapshot() error LoadSnapshot() error }
A server is involved in the consensus protocol and can act as a follower, candidate or a leader.
func NewServer ¶
func NewServer(name string, path string, transporter Transporter, stateMachine StateMachine, context interface{}, connectionString string) (Server, error)
Creates a new server with a log at the given path.
type Snapshot ¶
type Snapshot struct { LastIndex uint64 `json:"lastIndex"` LastTerm uint64 `json:"lastTerm"` // cluster configuration. Peers []*Peer `json:"peers"` State []byte `json:"state"` Path string `json:"path"` }
the in memory SnapShot struct TODO add cluster configuration
type SnapshotRecoveryRequest ¶
type SnapshotRecoveryRequest struct { LeaderName string LastIndex uint64 LastTerm uint64 Peers []*Peer State []byte }
The request sent to a server to start from the snapshot.
type SnapshotRecoveryResponse ¶
The response returned from a server appending entries to the log.
type SnapshotRequest ¶
The request sent to a server to start from the snapshot.
type SnapshotResponse ¶
type SnapshotResponse struct {
Success bool `json:"success"`
}
The response returned if the follower entered snapshot state
type StateMachine ¶
StateMachine is the interface for allowing the host application to save and recovery the state machine
type Transporter ¶
type Transporter interface { SendVoteRequest(server Server, peer *Peer, req *RequestVoteRequest) *RequestVoteResponse SendAppendEntriesRequest(server Server, peer *Peer, req *AppendEntriesRequest) *AppendEntriesResponse SendSnapshotRequest(server Server, peer *Peer, req *SnapshotRequest) *SnapshotResponse SendSnapshotRecoveryRequest(server Server, peer *Peer, req *SnapshotRecoveryRequest) *SnapshotRecoveryResponse }
Transporter is the interface for allowing the host application to transport requests to other nodes.
Source Files ¶
- append_entries_request.go
- append_entries_response.go
- command.go
- config.go
- debug.go
- http_transporter.go
- join_command.go
- leave_command.go
- log.go
- log_entry.go
- nop_command.go
- peer.go
- request_vote_request.go
- request_vote_response.go
- server.go
- snapshot.go
- snapshot_recovery_request.go
- snapshot_recovery_response.go
- snapshot_request.go
- snapshot_response.go
- sort.go
- statemachine.go
- test.go
- time.go
- timer.go
- transporter.go