Safe Haskell	None
Language	Haskell2010

Raft

Contents

State machine type class
Networking type classes
Client data types
Configuration
Events
Log
Logging
Raft node states
Persistent state
Basic types
RPC

Synopsis

class RSMP sm v | sm -> v where
- data RSMPError sm v
- type RSMPCtx sm v = ctx | ctx -> sm v
- applyCmdRSMP :: RSMPCtx sm v -> sm -> v -> Either (RSMPError sm v) sm
class (Monad m, RSMP sm v) => RSM sm v m | m sm -> v where
- validateCmd :: v -> m (Either (RSMPError sm v) ())
- askRSMPCtx :: m (RSMPCtx sm v)
class RaftSendRPC m v where
- sendRPC :: NodeId -> RPCMessage v -> m ()
class Show (RaftRecvRPCError m v) => RaftRecvRPC m v where
- type RaftRecvRPCError m v
- receiveRPC :: m (Either (RaftRecvRPCError m v) (RPCMessage v))
class RaftSendClient m sm where
- sendClient :: ClientId -> ClientResponse sm -> m ()
class Show (RaftRecvClientError m v) => RaftRecvClient m v where
- type RaftRecvClientError m v
- receiveClient :: m (Either (RaftRecvClientError m v) (ClientRequest v))
class Monad m => RaftPersist m where
- type RaftPersistError m
- readPersistentState :: Exception (RaftPersistError m) => m (Either (RaftPersistError m) PersistentState)
- writePersistentState :: Exception (RaftPersistError m) => PersistentState -> m (Either (RaftPersistError m) ())
type EventChan m v = TChan (STM m) (Event v)
data RaftEnv v m = RaftEnv {
- eventChan :: EventChan m v
- resetElectionTimer :: m ()
- resetHeartbeatTimer :: m ()
- raftNodeConfig :: NodeConfig
- raftNodeLogDest :: LogDest
}
runRaftNode :: (Show v, Show sm, Show (Action sm v), MonadIO m, MonadConc m, MonadFail m, RSM sm v m, Show (RSMPError sm v), RaftSendRPC m v, RaftRecvRPC m v, RaftSendClient m sm, RaftRecvClient m v, RaftLog m v, RaftLogExceptions m, RaftPersist m, Exception (RaftPersistError m)) => NodeConfig -> LogDest -> Int -> sm -> m ()
runRaftT :: MonadConc m => RaftNodeState -> RaftEnv v m -> RaftT v m () -> m ()
handleEventLoop :: forall sm v m. (Show v, Show sm, Show (Action sm v), MonadIO m, MonadConc m, MonadFail m, RSM sm v m, Show (RSMPError sm v), RaftPersist m, RaftSendRPC m v, RaftSendClient m sm, RaftLog m v, RaftLogExceptions m, RaftPersist m, Exception (RaftPersistError m)) => sm -> RaftT v m ()
data ClientRequest v = ClientRequest ClientId (ClientReq v)
data ClientReq v
- = ClientReadReq
- | ClientWriteReq v
data ClientResponse s
- = ClientReadResponse (ClientReadResp s)
- | ClientWriteResponse ClientWriteResp
- | ClientRedirectResponse ClientRedirResp
newtype ClientReadResp s = ClientReadResp s
data ClientWriteResp = ClientWriteResp Index
data ClientRedirResp = ClientRedirResp CurrentLeader
data NodeConfig = NodeConfig {
- configNodeId :: NodeId
- configNodeIds :: NodeIds
- configElectionTimeout :: (Natural, Natural)
- configHeartbeatTimeout :: Natural
}
data Event v
- = MessageEvent (MessageEvent v)
- | TimeoutEvent Timeout
data Timeout
- = ElectionTimeout
- | HeartbeatTimeout
data MessageEvent v
- = RPCMessageEvent (RPCMessage v)
- | ClientRequestEvent (ClientRequest v)
data Entry v = Entry {
- entryIndex :: Index
- entryTerm :: Term
- entryValue :: EntryValue v
- entryIssuer :: EntryIssuer
}
type Entries v = Seq (Entry v)
class Monad m => RaftWriteLog m v where
- type RaftWriteLogError m
- writeLogEntries :: Exception (RaftWriteLogError m) => Entries v -> m (Either (RaftWriteLogError m) ())
data DeleteSuccess v = DeleteSuccess
class Monad m => RaftDeleteLog m v where
- type RaftDeleteLogError m
- deleteLogEntriesFrom :: Exception (RaftDeleteLogError m) => Index -> m (Either (RaftDeleteLogError m) (DeleteSuccess v))
class Monad m => RaftReadLog m v where
- type RaftReadLogError m
- readLogEntry :: Exception (RaftReadLogError m) => Index -> m (Either (RaftReadLogError m) (Maybe (Entry v)))
- readLogEntriesFrom :: Exception (RaftReadLogError m) => Index -> m (Either (RaftReadLogError m) (Entries v))
- readLastLogEntry :: Exception (RaftReadLogError m) => m (Either (RaftReadLogError m) (Maybe (Entry v)))
type RaftLog m v = (RaftReadLog m v, RaftWriteLog m v, RaftDeleteLog m v)
data RaftLogError m
- = RaftLogReadError (RaftReadLogError m)
- | RaftLogWriteError (RaftWriteLogError m)
- | RaftLogDeleteError (RaftDeleteLogError m)
type RaftLogExceptions m = (Exception (RaftReadLogError m), Exception (RaftWriteLogError m), Exception (RaftDeleteLogError m))
data LogDest
- = LogFile FilePath
- | LogStdout
- | NoLogs
data Severity
- = Info
- | Debug
- | Critical
data Mode
- = Follower
- | Candidate
- | Leader
data RaftNodeState where
- RaftNodeState :: {..} -> RaftNodeState
data NodeState (a :: Mode) where
- NodeFollowerState :: FollowerState -> NodeState Follower
- NodeCandidateState :: CandidateState -> NodeState Candidate
- NodeLeaderState :: LeaderState -> NodeState Leader
data CurrentLeader
- = CurrentLeader LeaderId
- | NoLeader
data FollowerState = FollowerState {
- fsCurrentLeader :: CurrentLeader
- fsCommitIndex :: Index
- fsLastApplied :: Index
- fsLastLogEntryData :: (Index, Term)
- fsTermAtAEPrevIndex :: Maybe Term
}
data CandidateState = CandidateState {
- csCommitIndex :: Index
- csLastApplied :: Index
- csVotes :: NodeIds
- csLastLogEntryData :: (Index, Term)
}
data LeaderState = LeaderState {
- lsCommitIndex :: Index
- lsLastApplied :: Index
- lsNextIndex :: Map NodeId Index
- lsMatchIndex :: Map NodeId Index
- lsLastLogEntryData :: (Index, Term, Maybe EntryIssuer)
- lsReadReqsHandled :: Int
- lsReadRequest :: ClientReadReqs
}
initRaftNodeState :: RaftNodeState
isFollower :: NodeState s -> Bool
isCandidate :: NodeState s -> Bool
isLeader :: NodeState s -> Bool
setLastLogEntryData :: NodeState ns -> Entries v -> NodeState ns
getLastLogEntryData :: NodeState ns -> (Index, Term)
getLastAppliedAndCommitIndex :: NodeState ns -> (Index, Index)
data PersistentState = PersistentState {
- currentTerm :: Term
- votedFor :: Maybe NodeId
}
initPersistentState :: PersistentState
type NodeId = ByteString
type NodeIds = Set NodeId
newtype ClientId = ClientId NodeId
newtype LeaderId = LeaderId {
- unLeaderId :: NodeId
}
newtype Term = Term Natural
newtype Index = Index Natural
term0 :: Term
index0 :: Index
data RPC v
- = AppendEntriesRPC (AppendEntries v)
- | AppendEntriesResponseRPC AppendEntriesResponse
- | RequestVoteRPC RequestVote
- | RequestVoteResponseRPC RequestVoteResponse
class RPCType a v where
- toRPC :: a -> RPC v
data RPCMessage v = RPCMessage {
- sender :: NodeId
- rpc :: RPC v
}
data AppendEntries v = AppendEntries {
- aeTerm :: Term
- aeLeaderId :: LeaderId
- aePrevLogIndex :: Index
- aePrevLogTerm :: Term
- aeEntries :: Entries v
- aeLeaderCommit :: Index
- aeReadRequest :: Maybe Int
}
data AppendEntriesResponse = AppendEntriesResponse {
- aerTerm :: Term
- aerSuccess :: Bool
- aerReadRequest :: Maybe Int
}
data RequestVote = RequestVote {
- rvTerm :: Term
- rvCandidateId :: NodeId
- rvLastLogIndex :: Index
- rvLastLogTerm :: Term
}
data RequestVoteResponse = RequestVoteResponse {
- rvrTerm :: Term
- rvrVoteGranted :: Bool
}
data AppendEntriesData v = AppendEntriesData {
- aedTerm :: Term
- aedLeaderCommit :: Index
- aedEntriesSpec :: EntriesSpec v
}

State machine type class

class RSMP sm v | sm -> v where #

Interface to handle commands in the underlying state machine. Functional dependency permitting only a single state machine command to be defined to update the state machine.

Associated Types

data RSMPError sm v #

type RSMPCtx sm v = ctx | ctx -> sm v #

Methods

applyCmdRSMP :: RSMPCtx sm v -> sm -> v -> Either (RSMPError sm v) sm #

class (Monad m, RSMP sm v) => RSM sm v m | m sm -> v where #

Methods

validateCmd :: v -> m (Either (RSMPError sm v) ()) #

askRSMPCtx :: m (RSMPCtx sm v) #

Networking type classes

class RaftSendRPC m v where #

Interface for nodes to send messages to one another. E.g. Control.Concurrent.Chan, Network.Socket, etc.

Methods

sendRPC :: NodeId -> RPCMessage v -> m () #

Instances

(MonadIO m, MonadConc m, Serialize v, Show v) => RaftSendRPC (RaftSocketT v m) v #
Instance details Defined in Examples.Raft.Socket.Node Methods sendRPC :: NodeId -> RPCMessage v -> RaftSocketT v m () #

class Show (RaftRecvRPCError m v) => RaftRecvRPC m v where #

Interface for nodes to receive messages from one another

Associated Types

type RaftRecvRPCError m v #

Methods

receiveRPC :: m (Either (RaftRecvRPCError m v) (RPCMessage v)) #

Instances

(MonadIO m, MonadConc m, Show v) => RaftRecvRPC (RaftSocketT v m) v #
Instance details Defined in Examples.Raft.Socket.Node Associated Types type RaftRecvRPCError (RaftSocketT v m) v :: Type # Methods receiveRPC :: RaftSocketT v m (Either (RaftRecvRPCError (RaftSocketT v m) v) (RPCMessage v)) #

class RaftSendClient m sm where #

Interface for Raft nodes to send messages to clients

Methods

sendClient :: ClientId -> ClientResponse sm -> m () #

Instances

(MonadIO m, MonadConc m, Serialize sm) => RaftSendClient (RaftSocketT v m) sm #
Instance details Defined in Examples.Raft.Socket.Node Methods sendClient :: ClientId -> ClientResponse sm -> RaftSocketT v m () #

class Show (RaftRecvClientError m v) => RaftRecvClient m v where #

Interface for Raft nodes to receive messages from clients

Associated Types

type RaftRecvClientError m v #

Methods

receiveClient :: m (Either (RaftRecvClientError m v) (ClientRequest v)) #

Instances

(MonadIO m, MonadConc m, Serialize v) => RaftRecvClient (RaftSocketT v m) v #
Instance details Defined in Examples.Raft.Socket.Node Associated Types type RaftRecvClientError (RaftSocketT v m) v :: Type # Methods receiveClient :: RaftSocketT v m (Either (RaftRecvClientError (RaftSocketT v m) v) (ClientRequest v)) #

class Monad m => RaftPersist m where #

Provides an interface to read and write the persistent state to disk.

Associated Types

type RaftPersistError m #

Methods

readPersistentState :: Exception (RaftPersistError m) => m (Either (RaftPersistError m) PersistentState) #

writePersistentState :: Exception (RaftPersistError m) => PersistentState -> m (Either (RaftPersistError m) ()) #

Instances

(MonadIO m, MonadConc m) => RaftPersist (RaftFileStoreT m) #
Instance details Defined in Examples.Raft.FileStore Associated Types type RaftPersistError (RaftFileStoreT m) :: Type # Methods readPersistentState :: RaftFileStoreT m (Either (RaftPersistError (RaftFileStoreT m)) PersistentState) # writePersistentState :: PersistentState -> RaftFileStoreT m (Either (RaftPersistError (RaftFileStoreT m)) ()) #

type EventChan m v = TChan (STM m) (Event v) #

data RaftEnv v m #

The raft server environment composed of the concurrent variables used in the effectful raft layer.

Constructors

RaftEnv
Fields eventChan :: EventChan m v resetElectionTimer :: m () resetHeartbeatTimer :: m () raftNodeConfig :: NodeConfig raftNodeLogDest :: LogDest

runRaftNode #

Arguments

:: (Show v, Show sm, Show (Action sm v), MonadIO m, MonadConc m, MonadFail m, RSM sm v m, Show (RSMPError sm v), RaftSendRPC m v, RaftRecvRPC m v, RaftSendClient m sm, RaftRecvClient m v, RaftLog m v, RaftLogExceptions m, RaftPersist m, Exception (RaftPersistError m))
=> NodeConfig	Node configuration
-> LogDest	Logs destination
-> Int	Timer seed
-> sm	Initial state machine state
-> m ()

Run timers, RPC and client request handlers and start event loop. It should run forever

runRaftT :: MonadConc m => RaftNodeState -> RaftEnv v m -> RaftT v m () -> m () #

handleEventLoop :: forall sm v m. (Show v, Show sm, Show (Action sm v), MonadIO m, MonadConc m, MonadFail m, RSM sm v m, Show (RSMPError sm v), RaftPersist m, RaftSendRPC m v, RaftSendClient m sm, RaftLog m v, RaftLogExceptions m, RaftPersist m, Exception (RaftPersistError m)) => sm -> RaftT v m () #

Client data types

data ClientRequest v #

Representation of a client request coupled with the client id

Constructors

ClientRequest ClientId (ClientReq v)

Instances

Show v => Show (ClientRequest v) #
Instance details Defined in Raft.Client Methods showsPrec :: Int -> ClientRequest v -> ShowS # show :: ClientRequest v -> String # showList :: [ClientRequest v] -> ShowS #
Generic (ClientRequest v) #
Instance details Defined in Raft.Client Associated Types type Rep (ClientRequest v) :: Type -> Type # Methods from :: ClientRequest v -> Rep (ClientRequest v) x # to :: Rep (ClientRequest v) x -> ClientRequest v #
Serialize v => Serialize (ClientRequest v) #
Instance details Defined in Raft.Client Methods put :: Putter (ClientRequest v) # get :: Get (ClientRequest v) #
type Rep (ClientRequest v) #
Instance details Defined in Raft.Client type Rep (ClientRequest v) = D1 (MetaData "ClientRequest" "Raft.Client" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "ClientRequest" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 ClientId) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (ClientReq v))))

data ClientReq v #

Representation of a client request

Constructors

ClientReadReq	Request the latest state of the state machine
ClientWriteReq v	Write a command

Instances

Show v => Show (ClientReq v) #
Instance details Defined in Raft.Client Methods showsPrec :: Int -> ClientReq v -> ShowS # show :: ClientReq v -> String # showList :: [ClientReq v] -> ShowS #
Generic (ClientReq v) #
Instance details Defined in Raft.Client Associated Types type Rep (ClientReq v) :: Type -> Type # Methods from :: ClientReq v -> Rep (ClientReq v) x # to :: Rep (ClientReq v) x -> ClientReq v #
Serialize v => Serialize (ClientReq v) #
Instance details Defined in Raft.Client Methods put :: Putter (ClientReq v) # get :: Get (ClientReq v) #
type Rep (ClientReq v) #
Instance details Defined in Raft.Client type Rep (ClientReq v) = D1 (MetaData "ClientReq" "Raft.Client" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "ClientReadReq" PrefixI False) (U1 :: Type -> Type) :+: C1 (MetaCons "ClientWriteReq" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 v)))

data ClientResponse s #

Representation of a client response

Constructors

ClientReadResponse (ClientReadResp s)	Respond with the latest state of the state machine.
ClientWriteResponse ClientWriteResp	Respond with the index of the entry appended to the log
ClientRedirectResponse ClientRedirResp	Respond with the node id of the current leader

Instances

Show s => Show (ClientResponse s) #
Instance details Defined in Raft.Client Methods showsPrec :: Int -> ClientResponse s -> ShowS # show :: ClientResponse s -> String # showList :: [ClientResponse s] -> ShowS #
Generic (ClientResponse s) #
Instance details Defined in Raft.Client Associated Types type Rep (ClientResponse s) :: Type -> Type # Methods from :: ClientResponse s -> Rep (ClientResponse s) x # to :: Rep (ClientResponse s) x -> ClientResponse s #
Serialize s => Serialize (ClientResponse s) #
Instance details Defined in Raft.Client Methods put :: Putter (ClientResponse s) # get :: Get (ClientResponse s) #
type Rep (ClientResponse s) #
Instance details Defined in Raft.Client type Rep (ClientResponse s) = D1 (MetaData "ClientResponse" "Raft.Client" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "ClientReadResponse" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (ClientReadResp s))) :+: (C1 (MetaCons "ClientWriteResponse" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 ClientWriteResp)) :+: C1 (MetaCons "ClientRedirectResponse" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 ClientRedirResp))))

newtype ClientReadResp s #

Representation of a read response to a client The s stands for the "current" state of the state machine

Constructors

ClientReadResp s

Instances

Show s => Show (ClientReadResp s) #
Instance details Defined in Raft.Client Methods showsPrec :: Int -> ClientReadResp s -> ShowS # show :: ClientReadResp s -> String # showList :: [ClientReadResp s] -> ShowS #
Generic (ClientReadResp s) #
Instance details Defined in Raft.Client Associated Types type Rep (ClientReadResp s) :: Type -> Type # Methods from :: ClientReadResp s -> Rep (ClientReadResp s) x # to :: Rep (ClientReadResp s) x -> ClientReadResp s #
Serialize s => Serialize (ClientReadResp s) #
Instance details Defined in Raft.Client Methods put :: Putter (ClientReadResp s) # get :: Get (ClientReadResp s) #
type Rep (ClientReadResp s) #
Instance details Defined in Raft.Client type Rep (ClientReadResp s) = D1 (MetaData "ClientReadResp" "Raft.Client" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" True) (C1 (MetaCons "ClientReadResp" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 s)))

data ClientWriteResp #

Representation of a write response to a client

Constructors

ClientWriteResp Index

Index of the entry appended to the log due to the previous client request

Instances

Show ClientWriteResp #
Instance details Defined in Raft.Client Methods showsPrec :: Int -> ClientWriteResp -> ShowS # show :: ClientWriteResp -> String # showList :: [ClientWriteResp] -> ShowS #
Generic ClientWriteResp #
Instance details Defined in Raft.Client Associated Types type Rep ClientWriteResp :: Type -> Type # Methods from :: ClientWriteResp -> Rep ClientWriteResp x # to :: Rep ClientWriteResp x -> ClientWriteResp #
Serialize ClientWriteResp #
Instance details Defined in Raft.Client Methods put :: Putter ClientWriteResp # get :: Get ClientWriteResp #
type Rep ClientWriteResp #
Instance details Defined in Raft.Client type Rep ClientWriteResp = D1 (MetaData "ClientWriteResp" "Raft.Client" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "ClientWriteResp" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Index)))

data ClientRedirResp #

Representation of a redirect response to a client

Constructors

ClientRedirResp CurrentLeader

Instances

Show ClientRedirResp #
Instance details Defined in Raft.Client Methods showsPrec :: Int -> ClientRedirResp -> ShowS # show :: ClientRedirResp -> String # showList :: [ClientRedirResp] -> ShowS #
Generic ClientRedirResp #
Instance details Defined in Raft.Client Associated Types type Rep ClientRedirResp :: Type -> Type # Methods from :: ClientRedirResp -> Rep ClientRedirResp x # to :: Rep ClientRedirResp x -> ClientRedirResp #
Serialize ClientRedirResp #
Instance details Defined in Raft.Client Methods put :: Putter ClientRedirResp # get :: Get ClientRedirResp #
type Rep ClientRedirResp #
Instance details Defined in Raft.Client type Rep ClientRedirResp = D1 (MetaData "ClientRedirResp" "Raft.Client" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "ClientRedirResp" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 CurrentLeader)))

Configuration

data NodeConfig #

Configuration of a node in the cluster

Constructors

NodeConfig
Fields configNodeId :: NodeId Node id of the running node configNodeIds :: NodeIds Set of all other node ids in the cluster configElectionTimeout :: (Natural, Natural) Range of times an election timeout can take configHeartbeatTimeout :: Natural Heartbeat timeout timer

Instances

Show NodeConfig #
Instance details Defined in Raft.Config Methods showsPrec :: Int -> NodeConfig -> ShowS # show :: NodeConfig -> String # showList :: [NodeConfig] -> ShowS #

Events

data Event v #

Representation of events a raft node can send and receive

Constructors

MessageEvent (MessageEvent v)
TimeoutEvent Timeout

Instances

Show v => Show (Event v) #
Instance details Defined in Raft.Event Methods showsPrec :: Int -> Event v -> ShowS # show :: Event v -> String # showList :: [Event v] -> ShowS #

data Timeout #

Representation of timeouts

Constructors

ElectionTimeout	Timeout after which a follower will become candidate
HeartbeatTimeout	Timeout after which a leader will send AppendEntries RPC to all peers

Instances

Show Timeout #
Instance details Defined in Raft.Event Methods showsPrec :: Int -> Timeout -> ShowS # show :: Timeout -> String # showList :: [Timeout] -> ShowS #

data MessageEvent v #

Representation of message events to a node

Constructors

RPCMessageEvent (RPCMessage v)	Incoming event from a peer
ClientRequestEvent (ClientRequest v)	Incoming event from a client

Instances

Show v => Show (MessageEvent v) #
Instance details Defined in Raft.Event Methods showsPrec :: Int -> MessageEvent v -> ShowS # show :: MessageEvent v -> String # showList :: [MessageEvent v] -> ShowS #
Generic (MessageEvent v) #
Instance details Defined in Raft.Event Associated Types type Rep (MessageEvent v) :: Type -> Type # Methods from :: MessageEvent v -> Rep (MessageEvent v) x # to :: Rep (MessageEvent v) x -> MessageEvent v #
Serialize v => Serialize (MessageEvent v) #
Instance details Defined in Raft.Event Methods put :: Putter (MessageEvent v) # get :: Get (MessageEvent v) #
type Rep (MessageEvent v) #
Instance details Defined in Raft.Event type Rep (MessageEvent v) = D1 (MetaData "MessageEvent" "Raft.Event" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "RPCMessageEvent" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (RPCMessage v))) :+: C1 (MetaCons "ClientRequestEvent" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (ClientRequest v))))

Log

data Entry v #

Representation of an entry in the replicated log

Constructors

Entry
Fields entryIndex :: Index Index of entry in the log entryTerm :: Term Term when entry was received by leader entryValue :: EntryValue v Command to update state machine entryIssuer :: EntryIssuer Id of the client that issued the command

Instances

Show v => Show (Entry v) #
Instance details Defined in Raft.Log Methods showsPrec :: Int -> Entry v -> ShowS # show :: Entry v -> String # showList :: [Entry v] -> ShowS #
Generic (Entry v) #
Instance details Defined in Raft.Log Associated Types type Rep (Entry v) :: Type -> Type # Methods from :: Entry v -> Rep (Entry v) x # to :: Rep (Entry v) x -> Entry v #
Serialize v => Serialize (Entry v) #
Instance details Defined in Raft.Log Methods put :: Putter (Entry v) # get :: Get (Entry v) #
type Rep (Entry v) #
Instance details Defined in Raft.Log type Rep (Entry v) = D1 (MetaData "Entry" "Raft.Log" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "Entry" PrefixI True) ((S1 (MetaSel (Just "entryIndex") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Index) :: S1 (MetaSel (Just "entryTerm") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Term)) :: (S1 (MetaSel (Just "entryValue") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (EntryValue v)) :*: S1 (MetaSel (Just "entryIssuer") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 EntryIssuer))))

type Entries v = Seq (Entry v) #

class Monad m => RaftWriteLog m v where #

Provides an interface for nodes to write log entries to storage.

Associated Types

type RaftWriteLogError m #

Methods

writeLogEntries :: Exception (RaftWriteLogError m) => Entries v -> m (Either (RaftWriteLogError m) ()) #

Write the given log entries to storage

Instances

(MonadIO m, MonadConc m, Serialize v) => RaftWriteLog (RaftFileStoreT m) v #
Instance details Defined in Examples.Raft.FileStore Associated Types type RaftWriteLogError (RaftFileStoreT m) :: Type # Methods writeLogEntries :: Entries v -> RaftFileStoreT m (Either (RaftWriteLogError (RaftFileStoreT m)) ()) #

data DeleteSuccess v #

Constructors

DeleteSuccess

class Monad m => RaftDeleteLog m v where #

Provides an interface for nodes to delete log entries from storage.

Associated Types

type RaftDeleteLogError m #

Methods

deleteLogEntriesFrom :: Exception (RaftDeleteLogError m) => Index -> m (Either (RaftDeleteLogError m) (DeleteSuccess v)) #

Delete log entries from a given index; e.g. 'deleteLogEntriesFrom 7' should delete every log entry with an index >= 7.

Instances

(MonadIO m, MonadConc m, Serialize v) => RaftDeleteLog (RaftFileStoreT m) v #
Instance details Defined in Examples.Raft.FileStore Associated Types type RaftDeleteLogError (RaftFileStoreT m) :: Type # Methods deleteLogEntriesFrom :: Index -> RaftFileStoreT m (Either (RaftDeleteLogError (RaftFileStoreT m)) (DeleteSuccess v)) #

class Monad m => RaftReadLog m v where #

Provides an interface for nodes to read log entries from storage.

Minimal complete definition

readLogEntry, readLastLogEntry

Associated Types

type RaftReadLogError m #

Methods

readLogEntry :: Exception (RaftReadLogError m) => Index -> m (Either (RaftReadLogError m) (Maybe (Entry v))) #

Read the log at a given index

readLogEntriesFrom :: Exception (RaftReadLogError m) => Index -> m (Either (RaftReadLogError m) (Entries v)) #

Read log entries from a specific index onwards, including the specific index

readLastLogEntry :: Exception (RaftReadLogError m) => m (Either (RaftReadLogError m) (Maybe (Entry v))) #

Read the last log entry in the log

readLogEntriesFrom :: Exception (RaftReadLogError m) => Index -> m (Either (RaftReadLogError m) (Entries v)) #

Read log entries from a specific index onwards, including the specific index

Instances

(MonadIO m, MonadConc m, Serialize v) => RaftReadLog (RaftFileStoreT m) v #

Instance details

Defined in Examples.Raft.FileStore

Associated Types

type RaftReadLogError (RaftFileStoreT m) :: Type #

Methods

readLogEntry :: Index -> RaftFileStoreT m (Either (RaftReadLogError (RaftFileStoreT m)) (Maybe (Entry v))) #

readLogEntriesFrom :: Index -> RaftFileStoreT m (Either (RaftReadLogError (RaftFileStoreT m)) (Entries v)) #

readLastLogEntry :: RaftFileStoreT m (Either (RaftReadLogError (RaftFileStoreT m)) (Maybe (Entry v))) #

type RaftLog m v = (RaftReadLog m v, RaftWriteLog m v, RaftDeleteLog m v) #

data RaftLogError m #

Representation of possible errors that come from reading, writing or deleting logs from the persistent storage

Constructors

RaftLogReadError (RaftReadLogError m)
RaftLogWriteError (RaftWriteLogError m)
RaftLogDeleteError (RaftDeleteLogError m)

type RaftLogExceptions m = (Exception (RaftReadLogError m), Exception (RaftWriteLogError m), Exception (RaftDeleteLogError m)) #

Logging

data LogDest #

Representation of the logs' destination

Constructors

LogFile FilePath
LogStdout
NoLogs

data Severity #

Representation of the severity of the logs

Constructors

Info
Debug
Critical

Instances

Show Severity #
Instance details Defined in Raft.Logging Methods showsPrec :: Int -> Severity -> ShowS # show :: Severity -> String # showList :: [Severity] -> ShowS #

Raft node states

data Mode #

Constructors

Follower
Candidate
Leader

Instances

Show Mode #
Instance details Defined in Raft.NodeState Methods showsPrec :: Int -> Mode -> ShowS # show :: Mode -> String # showList :: [Mode] -> ShowS #

data RaftNodeState where #

Existential type hiding the internal node state

Constructors

RaftNodeState
Fields :: { unRaftNodeState :: NodeState s } -> RaftNodeState

Instances

Show RaftNodeState #
Instance details Defined in Raft.NodeState Methods showsPrec :: Int -> RaftNodeState -> ShowS # show :: RaftNodeState -> String # showList :: [RaftNodeState] -> ShowS #

data NodeState (a :: Mode) where #

The volatile state of a Raft Node

Constructors

NodeFollowerState :: FollowerState -> NodeState Follower
NodeCandidateState :: CandidateState -> NodeState Candidate
NodeLeaderState :: LeaderState -> NodeState Leader

Instances

Show (NodeState v) #
Instance details Defined in Raft.NodeState Methods showsPrec :: Int -> NodeState v -> ShowS # show :: NodeState v -> String # showList :: [NodeState v] -> ShowS #

data CurrentLeader #

Representation of the current leader in the cluster. The system is considered to be unavailable if there is no leader

Constructors

CurrentLeader LeaderId
NoLeader

Instances

Eq CurrentLeader #
Instance details Defined in Raft.NodeState Methods (==) :: CurrentLeader -> CurrentLeader -> Bool # (/=) :: CurrentLeader -> CurrentLeader -> Bool #
Show CurrentLeader #
Instance details Defined in Raft.NodeState Methods showsPrec :: Int -> CurrentLeader -> ShowS # show :: CurrentLeader -> String # showList :: [CurrentLeader] -> ShowS #
Generic CurrentLeader #
Instance details Defined in Raft.NodeState Associated Types type Rep CurrentLeader :: Type -> Type # Methods from :: CurrentLeader -> Rep CurrentLeader x # to :: Rep CurrentLeader x -> CurrentLeader #
Serialize CurrentLeader #
Instance details Defined in Raft.NodeState Methods put :: Putter CurrentLeader # get :: Get CurrentLeader #
type Rep CurrentLeader #
Instance details Defined in Raft.NodeState type Rep CurrentLeader = D1 (MetaData "CurrentLeader" "Raft.NodeState" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "CurrentLeader" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 LeaderId)) :+: C1 (MetaCons "NoLeader" PrefixI False) (U1 :: Type -> Type))

data FollowerState #

Constructors

FollowerState
Fields fsCurrentLeader :: CurrentLeader Id of the current leader fsCommitIndex :: Index Index of highest log entry known to be committed fsLastApplied :: Index Index of highest log entry applied to state machine fsLastLogEntryData :: (Index, Term) Index and term of the last log entry in the node's log fsTermAtAEPrevIndex :: Maybe Term The term of the log entry specified in and AppendEntriesRPC

Instances

Show FollowerState #
Instance details Defined in Raft.NodeState Methods showsPrec :: Int -> FollowerState -> ShowS # show :: FollowerState -> String # showList :: [FollowerState] -> ShowS #

data CandidateState #

Constructors

CandidateState
Fields csCommitIndex :: Index Index of highest log entry known to be committed csLastApplied :: Index Index of highest log entry applied to state machine csVotes :: NodeIds Votes from other nodes in the raft network csLastLogEntryData :: (Index, Term) Index and term of the last log entry in the node's log

Instances

Show CandidateState #
Instance details Defined in Raft.NodeState Methods showsPrec :: Int -> CandidateState -> ShowS # show :: CandidateState -> String # showList :: [CandidateState] -> ShowS #

data LeaderState #

Constructors

LeaderState

Fields

lsCommitIndex :: Index
Index of highest log entry known to be committed
lsLastApplied :: Index
Index of highest log entry applied to state machine
lsNextIndex :: Map NodeId Index
For each server, index of the next log entry to send to that server
lsMatchIndex :: Map NodeId Index
For each server, index of highest log entry known to be replicated on server
lsLastLogEntryData :: (Index, Term, Maybe EntryIssuer)
Index, term, and client id of the last log entry in the node's log. The only time `Maybe ClientId` will be Nothing is at the initial term.
lsReadReqsHandled :: Int
Number of read requests handled this term
lsReadRequest :: ClientReadReqs
The number of successful responses received regarding a specific read request heartbeat.

Instances

Show LeaderState #
Instance details Defined in Raft.NodeState Methods showsPrec :: Int -> LeaderState -> ShowS # show :: LeaderState -> String # showList :: [LeaderState] -> ShowS #

initRaftNodeState :: RaftNodeState #

A node in Raft begins as a follower

isFollower :: NodeState s -> Bool #

Check if node is in a follower state

isCandidate :: NodeState s -> Bool #

Check if node is in a candidate state

isLeader :: NodeState s -> Bool #

Check if node is in a leader state

setLastLogEntryData :: NodeState ns -> Entries v -> NodeState ns #

Update the last log entry in the node's log

getLastLogEntryData :: NodeState ns -> (Index, Term) #

Get the last applied index and the commit index of the last log entry in the node's log

getLastAppliedAndCommitIndex :: NodeState ns -> (Index, Index) #

Get the index of highest log entry applied to state machine and the index of highest log entry known to be committed

Persistent state

data PersistentState #

Persistent state that all Raft nodes maintain, regardless of node state.

Constructors

PersistentState
Fields currentTerm :: Term Last term server has seen votedFor :: Maybe NodeId Candidate id that received vote in current term

Instances

Show PersistentState #
Instance details Defined in Raft.Persistent Methods showsPrec :: Int -> PersistentState -> ShowS # show :: PersistentState -> String # showList :: [PersistentState] -> ShowS #
Generic PersistentState #
Instance details Defined in Raft.Persistent Associated Types type Rep PersistentState :: Type -> Type # Methods from :: PersistentState -> Rep PersistentState x # to :: Rep PersistentState x -> PersistentState #
Serialize PersistentState #
Instance details Defined in Raft.Persistent Methods put :: Putter PersistentState # get :: Get PersistentState #
MonadState PersistentState (TransitionM sm v) #
Instance details Defined in Raft.Monad Methods get :: TransitionM sm v PersistentState # put :: PersistentState -> TransitionM sm v () # state :: (PersistentState -> (a, PersistentState)) -> TransitionM sm v a #
RaftLogger (RWS (TransitionEnv sm) [Action sm v] PersistentState) #
Instance details Defined in Raft.Monad Methods loggerNodeId :: RWS (TransitionEnv sm) [Action sm v] PersistentState NodeId # loggerNodeState :: RWS (TransitionEnv sm) [Action sm v] PersistentState RaftNodeState #
type Rep PersistentState #
Instance details Defined in Raft.Persistent type Rep PersistentState = D1 (MetaData "PersistentState" "Raft.Persistent" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "PersistentState" PrefixI True) (S1 (MetaSel (Just "currentTerm") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Term) :*: S1 (MetaSel (Just "votedFor") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe NodeId))))

initPersistentState :: PersistentState #

A node initiates its persistent state with term 0 and with its vote blank

Basic types

type NodeId = ByteString #

Unique identifier of a Raft node

type NodeIds = Set NodeId #

newtype ClientId #

Unique identifier of a client

Constructors

ClientId NodeId

Instances

Eq ClientId #
Instance details Defined in Raft.Types Methods (==) :: ClientId -> ClientId -> Bool # (/=) :: ClientId -> ClientId -> Bool #
Ord ClientId #
Instance details Defined in Raft.Types Methods compare :: ClientId -> ClientId -> Ordering # (<) :: ClientId -> ClientId -> Bool # (<=) :: ClientId -> ClientId -> Bool # (>) :: ClientId -> ClientId -> Bool # (>=) :: ClientId -> ClientId -> Bool # max :: ClientId -> ClientId -> ClientId # min :: ClientId -> ClientId -> ClientId #
Show ClientId #
Instance details Defined in Raft.Types Methods showsPrec :: Int -> ClientId -> ShowS # show :: ClientId -> String # showList :: [ClientId] -> ShowS #
Generic ClientId #
Instance details Defined in Raft.Types Associated Types type Rep ClientId :: Type -> Type # Methods from :: ClientId -> Rep ClientId x # to :: Rep ClientId x -> ClientId #
Serialize ClientId #
Instance details Defined in Raft.Types Methods put :: Putter ClientId # get :: Get ClientId #
type Rep ClientId #
Instance details Defined in Raft.Types type Rep ClientId = D1 (MetaData "ClientId" "Raft.Types" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" True) (C1 (MetaCons "ClientId" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 NodeId)))

newtype LeaderId #

Unique identifier of a leader

Constructors

LeaderId
Fields unLeaderId :: NodeId

Instances

Eq LeaderId #
Instance details Defined in Raft.Types Methods (==) :: LeaderId -> LeaderId -> Bool # (/=) :: LeaderId -> LeaderId -> Bool #
Show LeaderId #
Instance details Defined in Raft.Types Methods showsPrec :: Int -> LeaderId -> ShowS # show :: LeaderId -> String # showList :: [LeaderId] -> ShowS #
Generic LeaderId #
Instance details Defined in Raft.Types Associated Types type Rep LeaderId :: Type -> Type # Methods from :: LeaderId -> Rep LeaderId x # to :: Rep LeaderId x -> LeaderId #
Serialize LeaderId #
Instance details Defined in Raft.Types Methods put :: Putter LeaderId # get :: Get LeaderId #
type Rep LeaderId #
Instance details Defined in Raft.Types type Rep LeaderId = D1 (MetaData "LeaderId" "Raft.Types" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" True) (C1 (MetaCons "LeaderId" PrefixI True) (S1 (MetaSel (Just "unLeaderId") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 NodeId)))

newtype Term #

Representation of monotonic election terms

Constructors

Term Natural

Instances

Enum Term #
Instance details Defined in Raft.Types Methods succ :: Term -> Term # pred :: Term -> Term # toEnum :: Int -> Term # fromEnum :: Term -> Int # enumFrom :: Term -> [Term] # enumFromThen :: Term -> Term -> [Term] # enumFromTo :: Term -> Term -> [Term] # enumFromThenTo :: Term -> Term -> Term -> [Term] #
Eq Term #
Instance details Defined in Raft.Types Methods (==) :: Term -> Term -> Bool # (/=) :: Term -> Term -> Bool #
Ord Term #
Instance details Defined in Raft.Types Methods compare :: Term -> Term -> Ordering # (<) :: Term -> Term -> Bool # (<=) :: Term -> Term -> Bool # (>) :: Term -> Term -> Bool # (>=) :: Term -> Term -> Bool # max :: Term -> Term -> Term # min :: Term -> Term -> Term #
Show Term #
Instance details Defined in Raft.Types Methods showsPrec :: Int -> Term -> ShowS # show :: Term -> String # showList :: [Term] -> ShowS #
Generic Term #
Instance details Defined in Raft.Types Associated Types type Rep Term :: Type -> Type # Methods from :: Term -> Rep Term x # to :: Rep Term x -> Term #
Serialize Term #
Instance details Defined in Raft.Types Methods put :: Putter Term # get :: Get Term #
type Rep Term #
Instance details Defined in Raft.Types type Rep Term = D1 (MetaData "Term" "Raft.Types" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" True) (C1 (MetaCons "Term" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Natural)))

newtype Index #

Representation of monotonic indices

Constructors

Index Natural

Instances

Enum Index #
Instance details Defined in Raft.Types Methods succ :: Index -> Index # pred :: Index -> Index # toEnum :: Int -> Index # fromEnum :: Index -> Int # enumFrom :: Index -> [Index] # enumFromThen :: Index -> Index -> [Index] # enumFromTo :: Index -> Index -> [Index] # enumFromThenTo :: Index -> Index -> Index -> [Index] #
Eq Index #
Instance details Defined in Raft.Types Methods (==) :: Index -> Index -> Bool # (/=) :: Index -> Index -> Bool #
Integral Index #
Instance details Defined in Raft.Types Methods quot :: Index -> Index -> Index # rem :: Index -> Index -> Index # div :: Index -> Index -> Index # mod :: Index -> Index -> Index # quotRem :: Index -> Index -> (Index, Index) # divMod :: Index -> Index -> (Index, Index) # toInteger :: Index -> Integer #
Num Index #
Instance details Defined in Raft.Types Methods (+) :: Index -> Index -> Index # (-) :: Index -> Index -> Index # (*) :: Index -> Index -> Index # negate :: Index -> Index # abs :: Index -> Index # signum :: Index -> Index # fromInteger :: Integer -> Index #
Ord Index #
Instance details Defined in Raft.Types Methods compare :: Index -> Index -> Ordering # (<) :: Index -> Index -> Bool # (<=) :: Index -> Index -> Bool # (>) :: Index -> Index -> Bool # (>=) :: Index -> Index -> Bool # max :: Index -> Index -> Index # min :: Index -> Index -> Index #
Real Index #
Instance details Defined in Raft.Types Methods toRational :: Index -> Rational #
Show Index #
Instance details Defined in Raft.Types Methods showsPrec :: Int -> Index -> ShowS # show :: Index -> String # showList :: [Index] -> ShowS #
Generic Index #
Instance details Defined in Raft.Types Associated Types type Rep Index :: Type -> Type # Methods from :: Index -> Rep Index x # to :: Rep Index x -> Index #
Serialize Index #
Instance details Defined in Raft.Types Methods put :: Putter Index # get :: Get Index #
type Rep Index #
Instance details Defined in Raft.Types type Rep Index = D1 (MetaData "Index" "Raft.Types" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" True) (C1 (MetaCons "Index" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Natural)))

term0 :: Term #

Initial term. Terms start at 0

index0 :: Index #

Initial index. Indeces start at 0

RPC

data RPC v #

Constructors

AppendEntriesRPC (AppendEntries v)
AppendEntriesResponseRPC AppendEntriesResponse
RequestVoteRPC RequestVote
RequestVoteResponseRPC RequestVoteResponse

Instances

Show v => Show (RPC v) #
Instance details Defined in Raft.RPC Methods showsPrec :: Int -> RPC v -> ShowS # show :: RPC v -> String # showList :: [RPC v] -> ShowS #
Generic (RPC v) #
Instance details Defined in Raft.RPC Associated Types type Rep (RPC v) :: Type -> Type # Methods from :: RPC v -> Rep (RPC v) x # to :: Rep (RPC v) x -> RPC v #
Serialize v => Serialize (RPC v) #
Instance details Defined in Raft.RPC Methods put :: Putter (RPC v) # get :: Get (RPC v) #
type Rep (RPC v) #
Instance details Defined in Raft.RPC type Rep (RPC v) = D1 (MetaData "RPC" "Raft.RPC" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) ((C1 (MetaCons "AppendEntriesRPC" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (AppendEntries v))) :+: C1 (MetaCons "AppendEntriesResponseRPC" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 AppendEntriesResponse))) :+: (C1 (MetaCons "RequestVoteRPC" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 RequestVote)) :+: C1 (MetaCons "RequestVoteResponseRPC" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 RequestVoteResponse))))

class RPCType a v where #

Methods

toRPC :: a -> RPC v #

Instances

RPCType RequestVoteResponse v #
Instance details Defined in Raft.RPC Methods toRPC :: RequestVoteResponse -> RPC v #
RPCType RequestVote v #
Instance details Defined in Raft.RPC Methods toRPC :: RequestVote -> RPC v #
RPCType AppendEntriesResponse v #
Instance details Defined in Raft.RPC Methods toRPC :: AppendEntriesResponse -> RPC v #
RPCType (AppendEntries v) v #
Instance details Defined in Raft.RPC Methods toRPC :: AppendEntries v -> RPC v #

data RPCMessage v #

Representation of a message sent between nodes

Constructors

RPCMessage
Fields sender :: NodeId rpc :: RPC v

Instances

Show v => Show (RPCMessage v) #
Instance details Defined in Raft.RPC Methods showsPrec :: Int -> RPCMessage v -> ShowS # show :: RPCMessage v -> String # showList :: [RPCMessage v] -> ShowS #
Generic (RPCMessage v) #
Instance details Defined in Raft.RPC Associated Types type Rep (RPCMessage v) :: Type -> Type # Methods from :: RPCMessage v -> Rep (RPCMessage v) x # to :: Rep (RPCMessage v) x -> RPCMessage v #
Serialize v => Serialize (RPCMessage v) #
Instance details Defined in Raft.RPC Methods put :: Putter (RPCMessage v) # get :: Get (RPCMessage v) #
type Rep (RPCMessage v) #
Instance details Defined in Raft.RPC type Rep (RPCMessage v) = D1 (MetaData "RPCMessage" "Raft.RPC" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "RPCMessage" PrefixI True) (S1 (MetaSel (Just "sender") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 NodeId) :*: S1 (MetaSel (Just "rpc") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (RPC v))))

data AppendEntries v #

Representation of a message sent from a leader to its peers

Constructors

AppendEntries

Fields

aeTerm :: Term
Leader's term
aeLeaderId :: LeaderId
Leader's identifier so that followers can redirect clients
aePrevLogIndex :: Index
Index of log entry immediately preceding new ones
aePrevLogTerm :: Term
Term of aePrevLogIndex entry
aeEntries :: Entries v
Log entries to store (empty for heartbeat)
aeLeaderCommit :: Index
Leader's commit index
aeReadRequest :: Maybe Int
which read request the message corresponds to

Instances

Show v => Show (AppendEntries v) #
Instance details Defined in Raft.RPC Methods showsPrec :: Int -> AppendEntries v -> ShowS # show :: AppendEntries v -> String # showList :: [AppendEntries v] -> ShowS #
Generic (AppendEntries v) #
Instance details Defined in Raft.RPC Associated Types type Rep (AppendEntries v) :: Type -> Type # Methods from :: AppendEntries v -> Rep (AppendEntries v) x # to :: Rep (AppendEntries v) x -> AppendEntries v #
Serialize v => Serialize (AppendEntries v) #
Instance details Defined in Raft.RPC Methods put :: Putter (AppendEntries v) # get :: Get (AppendEntries v) #
RPCType (AppendEntries v) v #
Instance details Defined in Raft.RPC Methods toRPC :: AppendEntries v -> RPC v #
type Rep (AppendEntries v) #
Instance details Defined in Raft.RPC type Rep (AppendEntries v) = D1 (MetaData "AppendEntries" "Raft.RPC" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "AppendEntries" PrefixI True) ((S1 (MetaSel (Just "aeTerm") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Term) :: (S1 (MetaSel (Just "aeLeaderId") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 LeaderId) :: S1 (MetaSel (Just "aePrevLogIndex") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Index))) :: ((S1 (MetaSel (Just "aePrevLogTerm") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Term) :: S1 (MetaSel (Just "aeEntries") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Entries v))) :: (S1 (MetaSel (Just "aeLeaderCommit") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Index) :: S1 (MetaSel (Just "aeReadRequest") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe Int))))))

data AppendEntriesResponse #

Representation of the response from a follower to an AppendEntries message

Constructors

AppendEntriesResponse
Fields aerTerm :: Term current term for leader to update itself aerSuccess :: Bool true if follower contained entry matching aePrevLogIndex and aePrevLogTerm aerReadRequest :: Maybe Int which read request the response corresponds to

Instances

Show AppendEntriesResponse #
Instance details Defined in Raft.RPC Methods showsPrec :: Int -> AppendEntriesResponse -> ShowS # show :: AppendEntriesResponse -> String # showList :: [AppendEntriesResponse] -> ShowS #
Generic AppendEntriesResponse #
Instance details Defined in Raft.RPC Associated Types type Rep AppendEntriesResponse :: Type -> Type # Methods from :: AppendEntriesResponse -> Rep AppendEntriesResponse x # to :: Rep AppendEntriesResponse x -> AppendEntriesResponse #
Serialize AppendEntriesResponse #
Instance details Defined in Raft.RPC Methods put :: Putter AppendEntriesResponse # get :: Get AppendEntriesResponse #
RPCType AppendEntriesResponse v #
Instance details Defined in Raft.RPC Methods toRPC :: AppendEntriesResponse -> RPC v #
type Rep AppendEntriesResponse #
Instance details Defined in Raft.RPC type Rep AppendEntriesResponse = D1 (MetaData "AppendEntriesResponse" "Raft.RPC" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "AppendEntriesResponse" PrefixI True) (S1 (MetaSel (Just "aerTerm") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Term) :: (S1 (MetaSel (Just "aerSuccess") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Bool) :: S1 (MetaSel (Just "aerReadRequest") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe Int)))))

data RequestVote #

Representation of the message sent by candidates to their peers to request their vote

Constructors

RequestVote
Fields rvTerm :: Term candidates term rvCandidateId :: NodeId candidate requesting vote rvLastLogIndex :: Index index of candidate's last log entry rvLastLogTerm :: Term term of candidate's last log entry

Instances

Show RequestVote #
Instance details Defined in Raft.RPC Methods showsPrec :: Int -> RequestVote -> ShowS # show :: RequestVote -> String # showList :: [RequestVote] -> ShowS #
Generic RequestVote #
Instance details Defined in Raft.RPC Associated Types type Rep RequestVote :: Type -> Type # Methods from :: RequestVote -> Rep RequestVote x # to :: Rep RequestVote x -> RequestVote #
Serialize RequestVote #
Instance details Defined in Raft.RPC Methods put :: Putter RequestVote # get :: Get RequestVote #
RPCType RequestVote v #
Instance details Defined in Raft.RPC Methods toRPC :: RequestVote -> RPC v #
type Rep RequestVote #
Instance details Defined in Raft.RPC type Rep RequestVote = D1 (MetaData "RequestVote" "Raft.RPC" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "RequestVote" PrefixI True) ((S1 (MetaSel (Just "rvTerm") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Term) :: S1 (MetaSel (Just "rvCandidateId") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 NodeId)) :: (S1 (MetaSel (Just "rvLastLogIndex") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Index) :*: S1 (MetaSel (Just "rvLastLogTerm") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Term))))

data RequestVoteResponse #

Representation of a response to a RequestVote message

Constructors

RequestVoteResponse
Fields rvrTerm :: Term current term for candidate to update itself rvrVoteGranted :: Bool true means candidate recieved vote

Instances

Show RequestVoteResponse #
Instance details Defined in Raft.RPC Methods showsPrec :: Int -> RequestVoteResponse -> ShowS # show :: RequestVoteResponse -> String # showList :: [RequestVoteResponse] -> ShowS #
Generic RequestVoteResponse #
Instance details Defined in Raft.RPC Associated Types type Rep RequestVoteResponse :: Type -> Type # Methods from :: RequestVoteResponse -> Rep RequestVoteResponse x # to :: Rep RequestVoteResponse x -> RequestVoteResponse #
Serialize RequestVoteResponse #
Instance details Defined in Raft.RPC Methods put :: Putter RequestVoteResponse # get :: Get RequestVoteResponse #
RPCType RequestVoteResponse v #
Instance details Defined in Raft.RPC Methods toRPC :: RequestVoteResponse -> RPC v #
type Rep RequestVoteResponse #
Instance details Defined in Raft.RPC type Rep RequestVoteResponse = D1 (MetaData "RequestVoteResponse" "Raft.RPC" "libraft-0.1.1.0-K88ErXXABXGJHe9OF75EJD" False) (C1 (MetaCons "RequestVoteResponse" PrefixI True) (S1 (MetaSel (Just "rvrTerm") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Term) :*: S1 (MetaSel (Just "rvrVoteGranted") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Bool)))

data AppendEntriesData v #

The data used to construct an AppendEntries value, snapshotted from the node state at the time the AppendEntries val should be created.

Constructors

AppendEntriesData
Fields aedTerm :: Term aedLeaderCommit :: Index aedEntriesSpec :: EntriesSpec v

Instances

Show v => Show (AppendEntriesData v) #
Instance details Defined in Raft.RPC Methods showsPrec :: Int -> AppendEntriesData v -> ShowS # show :: AppendEntriesData v -> String # showList :: [AppendEntriesData v] -> ShowS #