diff --git a/Hash2Pub.cabal b/Hash2Pub.cabal index 5ffff0d..376d675 100644 --- a/Hash2Pub.cabal +++ b/Hash2Pub.cabal @@ -46,8 +46,8 @@ category: Network extra-source-files: CHANGELOG.md common deps - build-depends: base ^>=4.12.0.0, containers ^>=0.6.0.1, bytestring, utf8-string ^>=1.0.1.1, network ^>=2.8.0.1, time ^>=1.8.0.2, cmdargs ^>= 0.10, cryptonite ^>= 0.25, memory, async, stm, asn1-encoding, asn1-types, asn1-parse, publicsuffix, network-byte-order, safe, iproute, mtl, random, servant, servant-server, servant-client, warp, text, unordered-containers, hashable, unicode-transforms, http-client, http-types - ghc-options: -Wall + build-depends: base >=4, containers ^>=0.6.0.1, bytestring, utf8-string ^>=1.0.1.1, network ^>=3.1, time, cmdargs ^>= 0.10, cryptonite, memory, async, stm, asn1-encoding, asn1-types, asn1-parse, publicsuffix, network-byte-order, safe, iproute, mtl, random, servant, servant-server, servant-client, warp, text, unordered-containers, hashable, unicode-transforms, http-client, http-types, unbounded-delays, dlist, formatting + ghc-options: -Wall -Wpartial-fields -O2 @@ -58,7 +58,7 @@ library exposed-modules: Hash2Pub.FediChord, Hash2Pub.FediChordTypes, Hash2Pub.DHTProtocol, Hash2Pub.ASN1Coding, Hash2Pub.ProtocolTypes, Hash2Pub.PostService, Hash2Pub.RingMap -- Modules included in this library but not exported. - other-modules: Hash2Pub.Utils + other-modules: Hash2Pub.Utils, Hash2Pub.PostService.API -- LANGUAGE extensions used by modules in this package. other-extensions: GeneralizedNewtypeDeriving, DataKinds, OverloadedStrings @@ -91,7 +91,21 @@ executable Hash2Pub -- Base language which the package is written in. default-language: Haskell2010 - ghc-options: -threaded + ghc-options: -threaded -rtsopts -with-rtsopts=-N + +executable Experiment + -- experiment runner + import: deps + + build-depends: Hash2Pub + + main-is: Experiment.hs + + hs-source-dirs: app + + default-language: Haskell2010 + + ghc-options: -threaded test-suite Hash2Pub-test diff --git a/Readme.md b/Readme.md index 3c7dbe5..e3cff3d 100644 --- a/Readme.md +++ b/Readme.md @@ -1,7 +1,7 @@ # Hash2Pub ***This is heavily WIP and does not provide any useful functionality yet***. -I aim for always having the master branch at a state where it builds and tests pass. +I aim for always having the `mainline` branch in a state where it builds and tests pass. A fully-decentralised relay for global hashtag federation in [ActivityPub](https://activitypub.rocks) based on a distributed hash table. It allows querying and subscribing to all posts of a certain hashtag and is implemented in Haskell. @@ -10,8 +10,13 @@ This is the practical implementation of the concept presented in the paper [Dece The ASN.1 module schema used for DHT messages can be found in `FediChord.asn1`. +For further questions and discussins, please refer to the **Hash2Pub topic in [SocialHub](https://socialhub.activitypub.rocks/c/software/hash2pub/48)**. + ## Building The project and its developent environment are built with [Nix](https://nixos.org/nix/). -The development environment can be entered with `nix-shell`. Then the project can be built with `cabal build` from within the environment, or using `nix-shell --command "cabal build"` to do both steps at once. +The development environment can be entered with `nix-shell shell-minimal.nix`. Then the project can be built with `cabal build` from within the environment, or using `nix-shell --command "cabal build" shell-minimal.nix` to do both steps at once. + +While the `shell-minimal.nix` environment contains everything necessary for building and testing this project, the `shell.nix` additionally contains the Haskell IDE engine *hie* and the documentation for all used Haskell packages for more convenient development. +Be aware that these need to be build from source and can take a very long time to build. diff --git a/app/Experiment.hs b/app/Experiment.hs new file mode 100644 index 0000000..f2fa586 --- /dev/null +++ b/app/Experiment.hs @@ -0,0 +1,51 @@ +{-# LANGUAGE OverloadedStrings #-} + +module Main where + +import Control.Concurrent +import Control.Monad (forM_) +import qualified Data.Text.Lazy as Txt +import qualified Data.Text.Lazy.IO as TxtI +import qualified Network.HTTP.Client as HTTP +import System.Environment (getArgs) + +import Hash2Pub.PostService (Hashtag, clientPublishPost) + +-- configuration constants +timelineFile = "../simulationData/inputs/generated/timeline_sample.csv" + +main :: IO () +main = do + -- read CLI parameters + speedupStr : _ <- getArgs + -- read and parse timeline schedule + -- relying on lazyness of HaskellIO, hoping it does not introduce too strong delays + postEvents <- parseSchedule <$> TxtI.readFile timelineFile + -- actually schedule and send the post events + executeSchedule (read speedupStr) postEvents + pure () + + + +parseSchedule :: Txt.Text + -> [(Int, Hashtag, (String, Int))] -- ^ [(delay in microseconds, hashtag, (hostname, port))] +parseSchedule = fmap (parseEntry . Txt.split (== ';')) . Txt.lines + where + parseEntry [delayT, contactT, tag] = + (read $ Txt.unpack delayT, tag, read $ Txt.unpack contactT) + parseEntry entry = error $ "invalid schedule input format: " <> show entry + +executeSchedule :: Int -- ^ speedup factor + -> [(Int, Hashtag, (String, Int))] -- ^ [(delay in microseconds, hashtag, (hostname, port))] + -> IO () +executeSchedule speedup events = do + -- initialise HTTP manager + httpMan <- HTTP.newManager $ HTTP.defaultManagerSettings { HTTP.managerResponseTimeout = HTTP.responseTimeoutMicro 60000000 } + forM_ events $ \(delay, tag, (pubHost, pubPort)) -> do + _ <- forkIO $ + clientPublishPost httpMan pubHost pubPort ("foobar #" <> tag) + >>= either putStrLn (const $ pure ()) + -- while threadDelay gives only minimum delay guarantees, let's hope the + -- additional delays are negligible + -- otherwise: evaluate usage of https://hackage.haskell.org/package/schedule-0.3.0.0/docs/Data-Schedule.html + threadDelay $ delay `div` speedup diff --git a/app/Main.hs b/app/Main.hs index 3bdb4d4..eac223d 100644 --- a/app/Main.hs +++ b/app/Main.hs @@ -45,21 +45,36 @@ main = do readConfig :: IO (FediChordConf, ServiceConf) readConfig = do - confDomainString : ipString : portString : bootstrapHost : bootstrapPortString : servicePortString : speedup : _ <- getArgs + confDomainString : ipString : portString : servicePortString : speedupString : remainingArgs <- getArgs + -- allow starting the initial node without bootstrapping info to avoid + -- waiting for timeout let - fConf = FediChordConf { - confDomain = confDomainString - , confIP = toHostAddress6 . read $ ipString - , confDhtPort = read portString - , confBootstrapNodes = [(bootstrapHost, read bootstrapPortString)] - --, confStabiliseInterval = 60 - , confBootstrapSamplingInterval = 180 - , confMaxLookupCacheAge = 300 - } - sConf = ServiceConf { - confSubscriptionExpiryTime = fromIntegral $ 2*3600 `div` (read speedup :: Integer) - , confServicePort = read servicePortString - , confServiceHost = confDomainString - } + speedup = read speedupString + confBootstrapNodes' = case remainingArgs of + bootstrapHost : bootstrapPortString : _ -> + [(bootstrapHost, read bootstrapPortString)] + _ -> [] + fConf = FediChordConf + { confDomain = confDomainString + , confIP = toHostAddress6 . read $ ipString + , confDhtPort = read portString + , confBootstrapNodes = confBootstrapNodes' + , confStabiliseInterval = 80 * 10^6 + , confBootstrapSamplingInterval = 180 * 10^6 `div` speedup + , confMaxLookupCacheAge = 300 / fromIntegral speedup + , confJoinAttemptsInterval = 60 * 10^6 `div` speedup + , confMaxNodeCacheAge = 600 / fromIntegral speedup + , confResponsePurgeAge = 60 / fromIntegral speedup + , confRequestTimeout = 5 * 10^6 `div` speedup + , confRequestRetries = 3 + } + sConf = ServiceConf + { confSubscriptionExpiryTime = 24*3600 / fromIntegral speedup + , confServicePort = read servicePortString + , confServiceHost = confDomainString + , confLogfilePath = "../simulationData/logs/" <> confDomainString <> ".log" + , confSpeedupFactor = speedup + , confStatsEvalDelay = 120 * 10^6 `div` speedup + } pure (fConf, sConf) diff --git a/default.nix b/default.nix index 4e77a05..a3f7640 100644 --- a/default.nix +++ b/default.nix @@ -1,26 +1,18 @@ { - compiler ? "ghc865", - withHIE ? false + compiler ? "ghc884" }: let - # pin all-hies for getting the language server - all-hies = fetchTarball { - url = "https://github.com/infinisil/all-hies/tarball/b8fb659620b99b4a393922abaa03a1695e2ca64d"; - sha256 = "sha256:0br6wsqpfk1lzz90f7zw439w1ir2p54268qilw9l2pk6yz7ganfx"; - }; pkgs = import ( builtins.fetchGit { name = "nixpkgs-pinned"; url = https://github.com/NixOS/nixpkgs/; - ref = "refs/heads/release-20.03"; - rev = "076c67fdea6d0529a568c7d0e0a72e6bc161ecf5"; + ref = "refs/heads/release-20.09"; + rev = "e065200fc90175a8f6e50e76ef10a48786126e1c"; }) { # Pass no config for purity config = {}; - overlays = [ - (import all-hies {}).overlay - ]; + overlays = []; }; hp = pkgs.haskell.packages."${compiler}"; src = pkgs.nix-gitignore.gitignoreSource [] ./.; @@ -38,7 +30,6 @@ in hlint stylish-haskell pkgs.python3Packages.asn1ate - ] - ++ (if withHIE then [ hie ] else []); + ]; }; } diff --git a/shell.nix b/shell.nix index dafd212..82fb296 100644 --- a/shell.nix +++ b/shell.nix @@ -1 +1 @@ -(import ./default.nix {withHIE = true;}).shell +(import ./default.nix {}).shell diff --git a/src/Hash2Pub/DHTProtocol.hs b/src/Hash2Pub/DHTProtocol.hs index bd7953f..c86c0f1 100644 --- a/src/Hash2Pub/DHTProtocol.hs +++ b/src/Hash2Pub/DHTProtocol.hs @@ -49,9 +49,11 @@ import Control.Concurrent.STM.TQueue import Control.Concurrent.STM.TVar import Control.Exception import Control.Monad (foldM, forM, forM_, void, when) +import Control.Monad.Except (MonadError (..), runExceptT) +import Control.Monad.IO.Class (MonadIO (..)) import qualified Data.ByteString as BS import Data.Either (rights) -import Data.Foldable (foldl', foldr') +import Data.Foldable (foldl', foldr', foldrM) import Data.Functor.Identity import Data.IP (IPv6, fromHostAddress6, toHostAddress6) @@ -106,9 +108,6 @@ queryLocalCache ownState nCache lBestNodes targetID -- the closest succeeding node (like with the p initiated parallel queries | otherwise = FORWARD $ closestSuccessor `Set.union` closestCachePredecessors (lBestNodes-1) targetID nCache where - ownID = getNid ownState - preds = predecessors ownState - closestSuccessor :: Set.Set RemoteCacheEntry closestSuccessor = maybe Set.empty (Set.singleton . toRemoteCacheEntry) $ cacheLookupSucc targetID nCache @@ -259,7 +258,6 @@ handleIncomingRequest :: Service s (RealNodeSTM s) -> SockAddr -- ^ source address of the request -> IO () handleIncomingRequest nsSTM sendQ msgSet sourceAddr = do - putStrLn $ "handling incoming request: " <> show msgSet ns <- readTVarIO nsSTM -- add nodestate to cache now <- getPOSIXTime @@ -314,7 +312,6 @@ handleIncomingRequest nsSTM sendQ msgSet sourceAddr = do -- | execute a key ID lookup on local cache and respond with the result respondQueryID :: LocalNodeStateSTM s -> Set.Set FediChordMessage -> IO (Map.Map Integer BS.ByteString) respondQueryID nsSTM msgSet = do - putStrLn "responding to a QueryID request" -- this message cannot be split reasonably, so just -- consider the first payload let @@ -435,7 +432,9 @@ respondJoin nsSTM msgSet = do let aRequestPart = Set.elemAt 0 msgSet senderNS = sender aRequestPart - responsibilityLookup = queryLocalCache nsSnap cache 1 (getNid senderNS) + -- if not joined yet, attract responsibility for + -- all keys to make bootstrapping possible + responsibilityLookup = if isJoined nsSnap then queryLocalCache nsSnap cache 1 (getNid senderNS) else FOUND (toRemoteNodeState nsSnap) thisNodeResponsible (FOUND _) = True thisNodeResponsible (FORWARD _) = False -- check whether the joining node falls into our responsibility @@ -489,10 +488,11 @@ requestJoin :: (NodeState a, Service s (RealNodeSTM s)) => a -- ^ cu requestJoin toJoinOn ownStateSTM = do ownState <- readTVarIO ownStateSTM prn <- readTVarIO $ parentRealNode ownState - srcAddr <- confIP . nodeConfig <$> readTVarIO (parentRealNode ownState) + nodeConf <- nodeConfig <$> readTVarIO (parentRealNode ownState) + let srcAddr = confIP nodeConf bracket (mkSendSocket srcAddr (getDomain toJoinOn) (getDhtPort toJoinOn)) close (\sock -> do -- extract own state for getting request information - responses <- sendRequestTo 5000 3 (\rid -> Request rid (toRemoteNodeState ownState) 1 True Join (Just JoinRequestPayload)) sock + responses <- sendRequestTo (confRequestTimeout nodeConf) (confRequestRetries nodeConf) (\rid -> Request rid (toRemoteNodeState ownState) 1 True Join (Just JoinRequestPayload)) sock (cacheInsertQ, joinedState) <- atomically $ do stateSnap <- readTVar ownStateSTM let @@ -517,28 +517,28 @@ requestJoin toJoinOn ownStateSTM = do ([], Set.empty, Set.empty) responses -- sort, slice and set the accumulated successors and predecessors - newState = setSuccessors (Set.elems succAccSet) . setPredecessors (Set.elems predAccSet) $ stateSnap + -- the contacted node itself is a successor as well and, with few + -- nodes, can be a predecessor as well + newState = setSuccessors (toRemoteNodeState toJoinOn:Set.elems succAccSet) . setPredecessors (toRemoteNodeState toJoinOn:Set.elems predAccSet) $ stateSnap writeTVar ownStateSTM newState pure (cacheInsertQ, newState) -- execute the cache insertions mapM_ (\f -> f joinedState) cacheInsertQ if responses == Set.empty then pure . Left $ "join error: got no response from " <> show (getNid toJoinOn) - else if null (predecessors joinedState) && null (successors joinedState) - then pure $ Left "join error: no predecessors or successors" - -- successful join - else do - -- wait for migration data to be completely received - waitForMigrationFrom (nodeService prn) (getNid ownState) - pure $ Right ownStateSTM + else do + -- wait for migration data to be completely received + waitForMigrationFrom (nodeService prn) (getNid toJoinOn) + pure $ Right ownStateSTM ) `catch` (\e -> pure . Left $ displayException (e :: IOException)) -- | Send a 'QueryID' 'Request' for getting the node that handles a certain key ID. -requestQueryID :: LocalNodeState s -- ^ NodeState of the querying node +requestQueryID :: (MonadIO m, MonadError String m) + => LocalNodeState s -- ^ NodeState of the querying node -> NodeID -- ^ target key ID to look up - -> IO RemoteNodeState -- ^ the node responsible for handling that key + -> m RemoteNodeState -- ^ the node responsible for handling that key -- 1. do a local lookup for the l closest nodes -- 2. create l sockets -- 3. send a message async concurrently to all l nodes @@ -546,23 +546,23 @@ requestQueryID :: LocalNodeState s -- ^ NodeState of the querying node -- 5. repeat until FOUND (problem: new entries not necessarily already in cache, explicitly compare with closer results) -- TODO: deal with lookup failures requestQueryID ns targetID = do - firstCacheSnapshot <- readTVarIO . nodeCacheSTM $ ns + firstCacheSnapshot <- liftIO . readTVarIO . nodeCacheSTM $ ns -- TODO: make maxAttempts configurable queryIdLookupLoop firstCacheSnapshot ns 50 targetID -- | like 'requestQueryID, but allows passing of a custom cache, e.g. for joining -queryIdLookupLoop :: NodeCache -> LocalNodeState s -> Int -> NodeID -> IO RemoteNodeState +queryIdLookupLoop :: (MonadIO m, MonadError String m) => NodeCache -> LocalNodeState s -> Int -> NodeID -> m RemoteNodeState -- return node itself as default fallback value against infinite recursion. -- TODO: consider using an Either instead of a default value -queryIdLookupLoop _ ns 0 _ = pure $ toRemoteNodeState ns +queryIdLookupLoop _ ns 0 _ = throwError "exhausted maximum lookup attempts" queryIdLookupLoop cacheSnapshot ns maxAttempts targetID = do let localResult = queryLocalCache ns cacheSnapshot (lNumBestNodes ns) targetID -- FOUND can only be returned if targetID is owned by local node case localResult of FOUND thisNode -> pure thisNode FORWARD nodeSet -> do - responseEntries <- sendQueryIdMessages targetID ns Nothing (remoteNode <$> Set.elems nodeSet) - now <- getPOSIXTime + responseEntries <- liftIO $ sendQueryIdMessages targetID ns Nothing (remoteNode <$> Set.elems nodeSet) + now <- liftIO getPOSIXTime -- check for a FOUND and return it case responseEntries of FOUND foundNode -> pure foundNode @@ -585,10 +585,10 @@ sendQueryIdMessages targetID ns lParam targets = do -- create connected sockets to all query targets and use them for request handling - srcAddr <- confIP . nodeConfig <$> readTVarIO (parentRealNode ns) - -- ToDo: make attempts and timeout configurable + nodeConf <- nodeConfig <$> readTVarIO (parentRealNode ns) + let srcAddr = confIP nodeConf queryThreads <- mapM (\resultNode -> async $ bracket (mkSendSocket srcAddr (getDomain resultNode) (getDhtPort resultNode)) close ( - sendRequestTo 5000 3 (lookupMessage targetID ns Nothing) + sendRequestTo (confRequestTimeout nodeConf) (confRequestRetries nodeConf) (lookupMessage targetID ns Nothing) )) targets -- ToDo: process results immediately instead of waiting for the last one to finish, see https://stackoverflow.com/a/38815224/9198613 -- ToDo: exception handling, maybe log them @@ -596,8 +596,10 @@ sendQueryIdMessages targetID ns lParam targets = do -- insert new cache entries both into global cache as well as return accumulated QueryResponses for further processing now <- getPOSIXTime -- collect cache entries from all responses - foldM (\acc resp -> do - let entrySet = case queryResult <$> payload resp of + foldrM (\resp acc -> do + let + responseResult = queryResult <$> payload resp + entrySet = case responseResult of Just (FOUND result1) -> Set.singleton (RemoteCacheEntry result1 now) Just (FORWARD resultset) -> resultset _ -> Set.empty @@ -607,10 +609,15 @@ sendQueryIdMessages targetID ns lParam targets = do -- return accumulated QueryResult pure $ case acc of -- once a FOUND as been encountered, return this as a result - isFound@FOUND{} -> isFound - FORWARD accSet -> FORWARD $ entrySet `Set.union` accSet + FOUND{} -> acc + FORWARD accSet + | maybe False isFound responseResult -> fromJust responseResult + | otherwise -> FORWARD $ entrySet `Set.union` accSet ) (FORWARD Set.empty) responses + where + isFound FOUND{} = True + isFound _ = False -- | Create a QueryID message to be supplied to 'sendRequestTo' lookupMessage :: Integral i @@ -629,8 +636,9 @@ requestStabilise :: LocalNodeState s -- ^ sending node -> RemoteNodeState -- ^ neighbour node to send to -> IO (Either String ([RemoteNodeState], [RemoteNodeState])) -- ^ (predecessors, successors) of responding node requestStabilise ns neighbour = do - srcAddr <- confIP . nodeConfig <$> readTVarIO (parentRealNode ns) - responses <- bracket (mkSendSocket srcAddr (getDomain neighbour) (getDhtPort neighbour)) close (fmap Right . sendRequestTo 5000 3 (\rid -> + nodeConf <- nodeConfig <$> readTVarIO (parentRealNode ns) + let srcAddr = confIP nodeConf + responses <- bracket (mkSendSocket srcAddr (getDomain neighbour) (getDhtPort neighbour)) close (fmap Right . sendRequestTo (confRequestTimeout nodeConf) (confRequestRetries nodeConf) (\rid -> Request { requestID = rid , sender = toRemoteNodeState ns @@ -652,8 +660,7 @@ requestStabilise ns neighbour = do ) ([],[]) respSet -- update successfully responded neighbour in cache - now <- getPOSIXTime - maybe (pure ()) (\p -> queueAddEntries (Identity $ RemoteCacheEntry (sender p) now) ns) $ headMay (Set.elems respSet) + maybe (pure ()) (\p -> queueUpdateVerifieds (Identity $ senderID p) ns) $ headMay (Set.elems respSet) pure $ if null responsePreds && null responseSuccs then Left "no neighbours returned" else Right (responsePreds, responseSuccs) @@ -668,13 +675,14 @@ requestLeave :: LocalNodeState s -> RemoteNodeState -- target node -> IO (Either String ()) -- error or success requestLeave ns doMigration target = do - srcAddr <- confIP . nodeConfig <$> readTVarIO (parentRealNode ns) - let leavePayload = LeaveRequestPayload { + nodeConf <- nodeConfig <$> readTVarIO (parentRealNode ns) + let srcAddr = confIP nodeConf + leavePayload = LeaveRequestPayload { leaveSuccessors = successors ns , leavePredecessors = predecessors ns , leaveDoMigration = doMigration } - responses <- bracket (mkSendSocket srcAddr (getDomain target) (getDhtPort target)) close (fmap Right . sendRequestTo 5000 3 (\rid -> + responses <- bracket (mkSendSocket srcAddr (getDomain target) (getDhtPort target)) close (fmap Right . sendRequestTo (confRequestTimeout nodeConf) (confRequestRetries nodeConf) (\rid -> Request { requestID = rid , sender = toRemoteNodeState ns @@ -696,10 +704,11 @@ requestPing :: LocalNodeState s -- ^ sending node -> RemoteNodeState -- ^ node to be PINGed -> IO (Either String [RemoteNodeState]) -- ^ all active vServers of the pinged node requestPing ns target = do - srcAddr <- confIP . nodeConfig <$> readTVarIO (parentRealNode ns) + nodeConf <- nodeConfig <$> readTVarIO (parentRealNode ns) + let srcAddr = confIP nodeConf responses <- bracket (mkSendSocket srcAddr (getDomain target) (getDhtPort target)) close (\sock -> do - resp <- sendRequestTo 5000 3 (\rid -> + resp <- sendRequestTo (confRequestTimeout nodeConf) (confRequestRetries nodeConf) (\rid -> Request { requestID = rid , sender = toRemoteNodeState ns @@ -735,10 +744,9 @@ requestPing ns target = do ) responses - -- | Generic function for sending a request over a connected socket and collecting the response. -- Serialises the message and tries to deliver its parts for a number of attempts within a specified timeout. -sendRequestTo :: Int -- ^ timeout in seconds +sendRequestTo :: Int -- ^ timeout in milliseconds -> Int -- ^ number of retries -> (Integer -> FediChordMessage) -- ^ the message to be sent, still needing a requestID -> Socket -- ^ connected socket to use for sending @@ -749,11 +757,10 @@ sendRequestTo timeoutMillis numAttempts msgIncomplete sock = do let msgComplete = msgIncomplete randomID requests = serialiseMessage sendMessageSize msgComplete - putStrLn $ "sending request message " <> show msgComplete -- create a queue for passing received response messages back, even after a timeout responseQ <- newTBQueueIO $ 2*maximumParts -- keep room for duplicate packets -- start sendAndAck with timeout - attempts numAttempts . timeout timeoutMillis $ sendAndAck responseQ sock requests + _ <- attempts numAttempts . timeout (timeoutMillis*1000) $ sendAndAck responseQ sock requests -- after timeout, check received responses, delete them from unacked message set/ map and rerun senAndAck with that if necessary. recvdParts <- atomically $ flushTBQueue responseQ pure $ Set.fromList recvdParts @@ -762,19 +769,20 @@ sendRequestTo timeoutMillis numAttempts msgIncomplete sock = do -> Socket -- ^ the socket used for sending and receiving for this particular remote node -> Map.Map Integer BS.ByteString -- ^ the remaining unacked request parts -> IO () - sendAndAck responseQueue sock remainingSends = do - sendMany sock $ Map.elems remainingSends + sendAndAck responseQueue sock' remainingSends = do + sendMany sock' $ Map.elems remainingSends -- if all requests have been acked/ responded to, return prematurely - recvLoop responseQueue remainingSends Set.empty Nothing - recvLoop :: TBQueue FediChordMessage -- ^ the queue for putting in the received responses + recvLoop sock' responseQueue remainingSends Set.empty Nothing + recvLoop :: Socket + -> TBQueue FediChordMessage -- ^ the queue for putting in the received responses -> Map.Map Integer BS.ByteString -- ^ the remaining unacked request parts -> Set.Set Integer -- ^ already received response part numbers - -> Maybe Integer -- ^ total number of response parts if already known + -> Maybe Integer -- ^ total number of response parts if already known -> IO () - recvLoop responseQueue remainingSends' receivedPartNums totalParts = do + recvLoop sock' responseQueue remainingSends' receivedPartNums totalParts = do -- 65535 is maximum length of UDP packets, as long as -- no IPv6 jumbograms are used - response <- deserialiseMessage <$> recv sock 65535 + response <- deserialiseMessage <$> recv sock' 65535 case response of Right msg@Response{} -> do atomically $ writeTBQueue responseQueue msg @@ -782,11 +790,12 @@ sendRequestTo timeoutMillis numAttempts msgIncomplete sock = do newTotalParts = if isFinalPart msg then Just (part msg) else totalParts newRemaining = Map.delete (part msg) remainingSends' newReceivedParts = Set.insert (part msg) receivedPartNums - if Map.null newRemaining && maybe False (\p -> Set.size receivedPartNums == fromIntegral p) newTotalParts + if Map.null newRemaining && maybe False (\p -> Set.size newReceivedParts == fromIntegral p) newTotalParts then pure () - else recvLoop responseQueue newRemaining receivedPartNums newTotalParts + else recvLoop sock' responseQueue newRemaining newReceivedParts newTotalParts -- drop errors and invalid messages - Left _ -> recvLoop responseQueue remainingSends' receivedPartNums totalParts + Right Request{} -> pure () -- expecting a response, not a request + Left _ -> recvLoop sock' responseQueue remainingSends' receivedPartNums totalParts -- | enqueue a list of RemoteCacheEntries to be added to the global NodeCache @@ -812,6 +821,18 @@ queueDeleteEntry :: NodeID -> IO () queueDeleteEntry toDelete = queueDeleteEntries $ Identity toDelete + +-- | enqueue the timestamp update and verification marking of an entry in the +-- global 'NodeCache'. +queueUpdateVerifieds :: Foldable c + => c NodeID + -> LocalNodeState s + -> IO () +queueUpdateVerifieds nIds ns = do + now <- getPOSIXTime + forM_ nIds $ \nid' -> atomically $ writeTQueue (cacheWriteQueue ns) $ + markCacheEntryAsVerified (Just now) nid' + -- | retry an IO action at most *i* times until it delivers a result attempts :: Int -- ^ number of retries *i* -> IO (Maybe a) -- ^ action to retry @@ -844,7 +865,7 @@ mkServerSocket ip port = do sockAddr <- addrAddress <$> resolve (Just $ show . fromHostAddress6 $ ip) (Just port) sock <- socket AF_INET6 Datagram defaultProtocol setSocketOption sock IPv6Only 1 - bind sock sockAddr + bind sock sockAddr `catch` (\e -> putStrLn $ "Caught exception while bind " <> show sock <> " " <> show sockAddr <> ": " <> show (e :: SomeException)) pure sock -- | create a UDP datagram socket, connected to a destination. @@ -860,6 +881,6 @@ mkSendSocket srcIp dest destPort = do setSocketOption sendSock IPv6Only 1 -- bind to the configured local IP to make sure that outgoing packets are sent from -- this source address - bind sendSock srcAddr + bind sendSock srcAddr `catch` (\e -> putStrLn $ "Caught exception while mkSendSocket bind " <> show sendSock <> " " <> show srcAddr <> ": " <> show (e :: SomeException)) connect sendSock destAddr pure sendSock diff --git a/src/Hash2Pub/FediChord.hs b/src/Hash2Pub/FediChord.hs index 15563de..9f14a1e 100644 --- a/src/Hash2Pub/FediChord.hs +++ b/src/Hash2Pub/FediChord.hs @@ -166,6 +166,7 @@ fediChordBootstrapJoin nsSTM bootstrapNode = do currentlyResponsible <- liftEither lookupResp liftIO . putStrLn $ "Trying to join on " <> show (getNid currentlyResponsible) -- 2. then send a join to the currently responsible node + liftIO $ putStrLn "send a bootstrap Join" joinResult <- liftIO $ requestJoin currentlyResponsible nsSTM liftEither joinResult @@ -198,7 +199,7 @@ convergenceSampleThread nsSTM = forever $ do -- unjoined node: try joining through all bootstrapping nodes else tryBootstrapJoining nsSTM >> pure () let delaySecs = confBootstrapSamplingInterval . nodeConfig $ parentNode - threadDelay $ delaySecs * 10^6 + threadDelay delaySecs -- | Try joining the DHT through any of the bootstrapping nodes until it succeeds. @@ -222,10 +223,11 @@ tryBootstrapJoining nsSTM = do bootstrapQueryId :: LocalNodeStateSTM s -> (String, PortNumber) -> NodeID -> IO (Either String RemoteNodeState) bootstrapQueryId nsSTM (bootstrapHost, bootstrapPort) targetID = do ns <- readTVarIO nsSTM - srcAddr <- confIP . nodeConfig <$> readTVarIO (parentRealNode ns) + nodeConf <- nodeConfig <$> readTVarIO (parentRealNode ns) + let srcAddr = confIP nodeConf bootstrapResponse <- bracket (mkSendSocket srcAddr bootstrapHost bootstrapPort) close ( -- Initialise an empty cache only with the responses from a bootstrapping node - fmap Right . sendRequestTo 5000 3 (lookupMessage targetID ns Nothing) + fmap Right . sendRequestTo (confRequestTimeout nodeConf) (confRequestRetries nodeConf) (lookupMessage targetID ns Nothing) ) `catch` (\e -> pure . Left $ "Error at bootstrap QueryId: " <> displayException (e :: IOException)) @@ -244,26 +246,24 @@ bootstrapQueryId nsSTM (bootstrapHost, bootstrapPort) targetID = do Just (FORWARD resultset) -> foldr' (addCacheEntryPure now) cacheAcc resultset ) initCache resp - currentlyResponsible <- queryIdLookupLoop bootstrapCache ns 50 $ getNid ns - pure $ Right currentlyResponsible + currentlyResponsible <- runExceptT $ queryIdLookupLoop bootstrapCache ns 50 $ getNid ns + pure currentlyResponsible -- | join a node to the DHT using the global node cache -- node's position. -fediChordVserverJoin :: Service s (RealNodeSTM s) +fediChordVserverJoin :: (MonadError String m, MonadIO m, Service s (RealNodeSTM s)) => LocalNodeStateSTM s -- ^ the local 'NodeState' - -> IO (Either String (LocalNodeStateSTM s)) -- ^ the joined 'NodeState' after a + -> m (LocalNodeStateSTM s) -- ^ the joined 'NodeState' after a -- successful join, otherwise an error message fediChordVserverJoin nsSTM = do - ns <- readTVarIO nsSTM + ns <- liftIO $ readTVarIO nsSTM -- 1. get routed to the currently responsible node currentlyResponsible <- requestQueryID ns $ getNid ns - putStrLn $ "Trying to join on " <> show (getNid currentlyResponsible) + liftIO . putStrLn $ "Trying to join on " <> show (getNid currentlyResponsible) -- 2. then send a join to the currently responsible node - joinResult <- requestJoin currentlyResponsible nsSTM - case joinResult of - Left err -> pure . Left $ "Error joining on " <> err - Right joinedNS -> pure . Right $ joinedNS + joinResult <- liftIO $ requestJoin currentlyResponsible nsSTM + liftEither joinResult fediChordVserverLeave :: (MonadError String m, MonadIO m, Service s (RealNodeSTM s)) => LocalNodeState s -> m () fediChordVserverLeave ns = do @@ -311,23 +311,23 @@ joinOnNewEntriesThread nsSTM = loop where loop = do nsSnap <- readTVarIO nsSTM - (lookupResult, cache) <- atomically $ do + (lookupResult, parentNode) <- atomically $ do cache <- readTVar $ nodeCacheSTM nsSnap + parentNode <- readTVar $ parentRealNode nsSnap case queryLocalCache nsSnap cache 1 (getNid nsSnap) of -- empty cache, block until cache changes and then retry (FORWARD s) | Set.null s -> retry - result -> pure (result, cache) + result -> pure (result, parentNode) case lookupResult of -- already joined FOUND _ -> pure () -- otherwise try joining FORWARD _ -> do - joinResult <- fediChordVserverJoin nsSTM + joinResult <- runExceptT $ fediChordVserverJoin nsSTM either -- on join failure, sleep and retry - -- TODO: make delay configurable - (const $ threadDelay (30 * 10^6) >> loop) + (const $ threadDelay (confJoinAttemptsInterval . nodeConfig $ parentNode) >> loop) (const $ pure ()) joinResult @@ -342,20 +342,15 @@ nodeCacheWriter nsSTM = modifyTVar' (nodeCacheSTM ns) cacheModifier --- TODO: make max entry age configurable -maxEntryAge :: POSIXTime -maxEntryAge = 600 - - -- | Periodically iterate through cache, clean up expired entries and verify unverified ones nodeCacheVerifyThread :: LocalNodeStateSTM s -> IO () nodeCacheVerifyThread nsSTM = forever $ do - putStrLn "cache verify run: begin" -- get cache - (ns, cache) <- atomically $ do + (ns, cache, maxEntryAge) <- atomically $ do ns <- readTVar nsSTM cache <- readTVar $ nodeCacheSTM ns - pure (ns, cache) + maxEntryAge <- confMaxNodeCacheAge . nodeConfig <$> readTVar (parentRealNode ns) + pure (ns, cache, maxEntryAge) -- iterate entries: -- for avoiding too many time syscalls, get current time before iterating. now <- getPOSIXTime @@ -402,8 +397,7 @@ nodeCacheVerifyThread nsSTM = forever $ do forkIO $ sendQueryIdMessages targetID latestNs (Just (1 + jEntriesPerSlice latestNs)) (nodesToQuery targetID) >> pure () -- ask for 1 entry more than j because of querying the middle ) - putStrLn "cache verify run: end" - threadDelay $ 10^6 * round maxEntryAge `div` 20 + threadDelay $ fromEnum (maxEntryAge / 20) `div` 10^6 -- convert from pico to milliseconds -- | Checks the invariant of at least @jEntries@ per cache slice. @@ -469,7 +463,6 @@ stabiliseThread :: Service s (RealNodeSTM s) => LocalNodeStateSTM s -> IO () stabiliseThread nsSTM = forever $ do oldNs <- readTVarIO nsSTM - putStrLn "stabilise run: begin" -- iterate through the same snapshot, collect potential new neighbours -- and nodes to be deleted, and modify these changes only at the end of @@ -504,18 +497,26 @@ stabiliseThread nsSTM = forever $ do -- try looking up additional neighbours if list too short forM_ [(length $ predecessors updatedNs)..(kNeighbours updatedNs)] (\_ -> do ns' <- readTVarIO nsSTM - nextEntry <- requestQueryID ns' $ pred . getNid $ lastDef (toRemoteNodeState ns') (predecessors ns') - atomically $ do - latestNs <- readTVar nsSTM - writeTVar nsSTM $ addPredecessors [nextEntry] latestNs + nextEntry <- runExceptT . requestQueryID ns' $ pred . getNid $ lastDef (toRemoteNodeState ns') (predecessors ns') + either + (const $ pure ()) + (\entry -> atomically $ do + latestNs <- readTVar nsSTM + writeTVar nsSTM $ addPredecessors [entry] latestNs + ) + nextEntry ) forM_ [(length $ successors updatedNs)..(kNeighbours updatedNs)] (\_ -> do ns' <- readTVarIO nsSTM - nextEntry <- requestQueryID ns' $ succ . getNid $ lastDef (toRemoteNodeState ns') (successors ns') - atomically $ do - latestNs <- readTVar nsSTM - writeTVar nsSTM $ addSuccessors [nextEntry] latestNs + nextEntry <- runExceptT . requestQueryID ns' $ succ . getNid $ lastDef (toRemoteNodeState ns') (successors ns') + either + (const $ pure ()) + (\entry -> atomically $ do + latestNs <- readTVar nsSTM + writeTVar nsSTM $ addSuccessors [entry] latestNs + ) + nextEntry ) newNs <- readTVarIO nsSTM @@ -540,9 +541,8 @@ stabiliseThread nsSTM = forever $ do ) newPredecessor - putStrLn "stabilise run: end" - -- TODO: make delay configurable - threadDelay (60 * 10^6) + stabiliseDelay <- confStabiliseInterval . nodeConfig <$> readTVarIO (parentRealNode newNs) + threadDelay stabiliseDelay where -- | send a stabilise request to the n-th neighbour -- (specified by the provided getter function) and on failure retry @@ -629,19 +629,15 @@ type RequestMap = Map.Map (SockAddr, Integer) RequestMapEntry data RequestMapEntry = RequestMapEntry (Set.Set FediChordMessage) (Maybe Integer) POSIXTime --- TODO: make purge age configurable --- | periodically clean up old request parts -responsePurgeAge :: POSIXTime -responsePurgeAge = 60 -- seconds -requestMapPurge :: MVar RequestMap -> IO () -requestMapPurge mapVar = forever $ do +requestMapPurge :: POSIXTime -> MVar RequestMap -> IO () +requestMapPurge purgeAge mapVar = forever $ do rMapState <- takeMVar mapVar now <- getPOSIXTime - putMVar mapVar $ Map.filter (\entry@(RequestMapEntry _ _ ts) -> - now - ts < responsePurgeAge + putMVar mapVar $ Map.filter (\(RequestMapEntry _ _ ts) -> + now - ts < purgeAge ) rMapState - threadDelay $ round responsePurgeAge * 2 * 10^6 + threadDelay $ (fromEnum purgeAge * 2) `div` 10^6 -- | Wait for messages, deserialise them, manage parts and acknowledgement status, @@ -656,12 +652,13 @@ fediMessageHandler sendQ recvQ nsSTM = do -- not change. -- Other functions are passed the nsSTM reference and thus can get the latest state. nsSnap <- readTVarIO nsSTM + nodeConf <- nodeConfig <$> readTVarIO (parentRealNode nsSnap) -- handling multipart messages: -- Request parts can be insert into a map (key: (sender IP against spoofing, request ID), value: timestamp + set of message parts, handle all of them when size of set == parts) before being handled. This map needs to be purged periodically by a separate thread and can be protected by an MVar for fairness. requestMap <- newMVar (Map.empty :: RequestMap) -- run receive loop and requestMapPurge concurrently, so that an exception makes -- both of them fail - concurrently_ (requestMapPurge requestMap) $ forever $ do + concurrently_ (requestMapPurge (confResponsePurgeAge nodeConf) requestMap) $ forever $ do -- wait for incoming messages (rawMsg, sourceAddr) <- atomically $ readTQueue recvQ let aMsg = deserialiseMessage rawMsg @@ -716,7 +713,7 @@ fediMessageHandler sendQ recvQ nsSTM = do instance DHT (RealNodeSTM s) where lookupKey nodeSTM keystring = getKeyResponsibility nodeSTM $ genKeyID keystring - forceLookupKey nodeSTM keystring = updateLookupCache nodeSTM $ genKeyID keystring + forceLookupKey nodeSTM keystring = (putStrLn $ "forced responsibility lookup of #" <> keystring) >> (updateLookupCache nodeSTM $ genKeyID keystring) -- potential better implementation: put all neighbours of all vservers and the vservers on a ringMap, look the key up and see whether it results in a LocalNodeState isResponsibleFor nodeSTM key = do node <- readTVarIO nodeSTM @@ -757,7 +754,7 @@ getKeyResponsibility nodeSTM lookupKey = do -- new entry. -- If no vserver is active in the DHT, 'Nothing' is returned. updateLookupCache :: RealNodeSTM s -> NodeID -> IO (Maybe (String, PortNumber)) -updateLookupCache nodeSTM lookupKey = do +updateLookupCache nodeSTM keyToLookup = do (node, lookupSource) <- atomically $ do node <- readTVar nodeSTM let firstVs = headMay (vservers node) @@ -767,18 +764,25 @@ updateLookupCache nodeSTM lookupKey = do pure (node, lookupSource) maybe (do -- if no local node available, delete cache entry and return Nothing - atomically $ modifyTVar' (lookupCacheSTM node) $ Map.delete lookupKey + atomically $ modifyTVar' (lookupCacheSTM node) $ Map.delete keyToLookup pure Nothing ) (\n -> do -- start a lookup from the node, update the cache with the lookup result and return it - newResponsible <- requestQueryID n lookupKey - let newEntry = (getDomain newResponsible, getServicePort newResponsible) - now <- getPOSIXTime - -- atomic update against lost updates - atomically $ modifyTVar' (lookupCacheSTM node) $ - Map.insert lookupKey (CacheEntry False newEntry now) - pure $ Just newEntry + -- TODO: better retry management, because having no vserver joined yet should + -- be treated differently than other reasons for not getting a result. + newResponsible <- runExceptT $ requestQueryID n keyToLookup + either + (const $ pure Nothing) + (\result -> do + let newEntry = (getDomain result, getServicePort result) + now <- getPOSIXTime + -- atomic update against lost updates + atomically $ modifyTVar' (lookupCacheSTM node) $ + Map.insert keyToLookup (CacheEntry False newEntry now) + pure $ Just newEntry + ) + newResponsible ) lookupSource @@ -793,4 +797,4 @@ lookupCacheCleanup nodeSTM = do now - ts < confMaxLookupCacheAge (nodeConfig node) ) ) - threadDelay $ round (confMaxLookupCacheAge $ nodeConfig node) * (10^5) + threadDelay $ fromEnum (2 * confMaxLookupCacheAge (nodeConfig node)) `div` 10^6 diff --git a/src/Hash2Pub/FediChordTypes.hs b/src/Hash2Pub/FediChordTypes.hs index cbd3a58..4ce20a7 100644 --- a/src/Hash2Pub/FediChordTypes.hs +++ b/src/Hash2Pub/FediChordTypes.hs @@ -411,10 +411,22 @@ data FediChordConf = FediChordConf -- ^ listening port for the FediChord DHT , confBootstrapNodes :: [(String, PortNumber)] -- ^ list of potential bootstrapping nodes + , confStabiliseInterval :: Int + -- ^ pause between stabilise runs, in milliseconds , confBootstrapSamplingInterval :: Int - -- ^ pause between sampling the own ID through bootstrap nodes, in seconds + -- ^ pause between sampling the own ID through bootstrap nodes, in milliseconds , confMaxLookupCacheAge :: POSIXTime - -- ^ maximum age of lookup cache entries in seconds + -- ^ maximum age of key lookup cache entries in seconds + , confJoinAttemptsInterval :: Int + -- ^ interval between join attempts on newly learned nodes, in milliseconds + , confMaxNodeCacheAge :: POSIXTime + -- ^ maximum age of entries in the node cache, in milliseconds + , confResponsePurgeAge :: POSIXTime + -- ^ maximum age of message parts in response part cache, in seconds + , confRequestTimeout :: Int + -- ^ how long to wait until response has arrived, in milliseconds + , confRequestRetries :: Int + -- ^ how often re-sending a timed-out request can be retried } deriving (Show, Eq) @@ -445,6 +457,12 @@ data ServiceConf = ServiceConf -- ^ listening port for service , confServiceHost :: String -- ^ hostname of service + , confLogfilePath :: String + -- ^ where to store the (measurement) log file + , confStatsEvalDelay :: Int + -- ^ delay between statistic rate measurement samplings, in microseconds + , confSpeedupFactor :: Int + -- While the speedup factor needs to be already included in all } class DHT d where diff --git a/src/Hash2Pub/PostService.hs b/src/Hash2Pub/PostService.hs index a871343..ffeef17 100644 --- a/src/Hash2Pub/PostService.hs +++ b/src/Hash2Pub/PostService.hs @@ -10,41 +10,43 @@ module Hash2Pub.PostService where import Control.Concurrent import Control.Concurrent.Async -import Control.Concurrent.MVar import Control.Concurrent.STM -import Control.Concurrent.STM.TChan -import Control.Concurrent.STM.TChan -import Control.Concurrent.STM.TQueue -import Control.Concurrent.STM.TVar -import Control.Exception (Exception (..), try) -import Control.Monad (foldM, forM, forM_, forever) -import Control.Monad.IO.Class (liftIO) -import Control.Monad.STM +import Control.Exception (Exception (..), try) +import Control.Monad (foldM, forM, forM_, forever, unless, + void, when) +import Control.Monad.IO.Class (liftIO) import Data.Bifunctor -import qualified Data.ByteString.Lazy.UTF8 as BSUL -import qualified Data.ByteString.UTF8 as BSU -import qualified Data.HashMap.Strict as HMap -import qualified Data.HashSet as HSet -import Data.Maybe (fromMaybe, isJust) -import Data.String (fromString) -import qualified Data.Text.Lazy as Txt -import Data.Text.Normalize (NormalizationMode (NFC), - normalize) +import qualified Data.ByteString.Lazy.UTF8 as BSUL +import qualified Data.ByteString.UTF8 as BSU +import qualified Data.DList as D +import Data.Either (lefts, rights) +import qualified Data.HashMap.Strict as HMap +import qualified Data.HashSet as HSet +import Data.Maybe (fromJust, isJust) +import Data.String (fromString) +import Data.Text.Lazy (Text) +import qualified Data.Text.Lazy as Txt +import qualified Data.Text.Lazy.IO as TxtI +import Data.Text.Normalize (NormalizationMode (NFC), normalize) import Data.Time.Clock.POSIX -import Data.Typeable (Typeable) -import qualified Network.HTTP.Client as HTTP -import qualified Network.HTTP.Types as HTTPT +import Data.Typeable (Typeable) +import qualified Network.HTTP.Client as HTTP +import qualified Network.HTTP.Types as HTTPT +import System.IO import System.Random -import Text.Read (readEither) +import Text.Read (readEither) -import qualified Network.Wai.Handler.Warp as Warp +import Formatting (fixed, format, int, (%)) +import qualified Network.Wai.Handler.Warp as Warp import Servant import Servant.Client -import Servant.Server import Hash2Pub.FediChordTypes +import Hash2Pub.PostService.API import Hash2Pub.RingMap +import Hash2Pub.Utils +import Debug.Trace data PostService d = PostService { serviceConf :: ServiceConf @@ -55,19 +57,22 @@ data PostService d = PostService -- ^ for each tag store the subscribers + their queue , ownSubscriptions :: TVar (HMap.HashMap NodeID POSIXTime) -- ^ tags subscribed by the own node have an assigned lease time - , ownPosts :: TVar (HSet.HashSet Txt.Text) - -- ^ just store the existence of posts for saving memory, , relayInQueue :: TQueue (Hashtag, PostID, PostContent) -- ^ Queue for processing incoming posts of own instance asynchronously , postFetchQueue :: TQueue PostID + -- ^ queue of posts to be fetched , migrationsInProgress :: TVar (HMap.HashMap NodeID (MVar ())) , httpMan :: HTTP.Manager + , statsQueue :: TQueue StatsEvent + , loadStats :: TVar RelayStats + -- ^ current load stats, replaced periodically + , logFileHandle :: Handle } deriving (Typeable) -type Hashtag = Txt.Text -type PostID = Txt.Text -type PostContent = Txt.Text +type Hashtag = Text +type PostID = Text +type PostContent = Text -- | For each handled tag, store its subscribers and provide a -- broadcast 'TChan' for enqueuing posts type RelayTags = RingMap NodeID (TagSubscribersSTM, TChan PostID, Hashtag) @@ -85,26 +90,38 @@ instance DHT d => Service PostService d where threadVar <- newTVarIO =<< myThreadId -- own thread ID as placeholder subscriberVar <- newTVarIO emptyRMap ownSubsVar <- newTVarIO HMap.empty - ownPostVar <- newTVarIO HSet.empty + --ownPostVar <- newTVarIO HSet.empty relayInQueue' <- newTQueueIO postFetchQueue' <- newTQueueIO migrationsInProgress' <- newTVarIO HMap.empty httpMan' <- HTTP.newManager HTTP.defaultManagerSettings + statsQueue' <- newTQueueIO + loadStats' <- newTVarIO emptyStats + loggingFile <- openFile (confLogfilePath conf) WriteMode + hSetBuffering loggingFile LineBuffering let - thisService = PostService { - serviceConf = conf + thisService = PostService + { serviceConf = conf , baseDHT = dht , serviceThread = threadVar , subscribers = subscriberVar , ownSubscriptions = ownSubsVar - , ownPosts = ownPostVar + --, ownPosts = ownPostVar , relayInQueue = relayInQueue' , postFetchQueue = postFetchQueue' , migrationsInProgress = migrationsInProgress' , httpMan = httpMan' - } + , statsQueue = statsQueue' + , loadStats = loadStats' + , logFileHandle = loggingFile + } port' = fromIntegral (confServicePort conf) warpSettings = Warp.setPort port' . Warp.setHost (fromString . confServiceHost $ conf) $ Warp.defaultSettings + -- log a start message, this also truncates existing files + TxtI.hPutStrLn loggingFile $ Txt.unlines + [ "# Starting mock relay implementation" + , "#time stamp ; relay receive rate ;relay delivery rate ;instance publish rate ;instance fetch rate ;total subscriptions" + ] -- Run 'concurrently_' from another thread to be able to return the -- 'PostService'. -- Terminating that parent thread will make all child threads terminate as well. @@ -112,7 +129,11 @@ instance DHT d => Service PostService d where concurrently_ -- web server (Warp.runSettings warpSettings $ postServiceApplication thisService) - (processIncomingPosts thisService) + $ concurrently + -- background processing workers + (launchWorkerThreads thisService) + -- statistics/ measurements + (launchStatsThreads thisService) -- update thread ID after fork atomically $ writeTVar threadVar servThreadID pure thisService @@ -138,38 +159,13 @@ postServiceApplication :: DHT d => PostService d -> Application postServiceApplication serv = serve exposedPostServiceAPI $ postServer serv --- | needed for guiding type inference -exposedPostServiceAPI :: Proxy PostServiceAPI -exposedPostServiceAPI = Proxy - -- ========= constants =========== -placeholderPost :: Txt.Text +placeholderPost :: Text placeholderPost = Txt.take 5120 . Txt.repeat $ 'O' -- size 5KiB -- ========= HTTP API and handlers ============= -type PostServiceAPI = "relay" :> "inbox" :> Capture "hashtag" Txt.Text :> ReqBody '[PlainText] Txt.Text :> PutCreated '[PlainText] NoContent - -- delivery endpoint of newly published posts of the relay's instance - :<|> "relay" :> "subscribers" :> Capture "senderID" Integer :> ReqBody '[PlainText] Txt.Text :> PostNoContent '[PlainText] Txt.Text - -- endpoint for delivering the subscriptions and outstanding queue - :<|> "post" :> Capture "postid" Txt.Text :> Get '[PlainText] Txt.Text - -- fetch endpoint for posts, full post ID is http://$domain/post/$postid - :<|> "posts" :> ReqBody '[PlainText] Txt.Text :> Post '[PlainText] Txt.Text - -- endpoint for fetching multiple posts at once - :<|> "posts" :> "inbox" :> ReqBody '[PlainText] Txt.Text :> PutCreated '[PlainText] NoContent - -- delivery endpoint of newly published posts of the relay's instance - :<|> "tags" :> Capture "hashtag" Txt.Text :> ReqBody '[PlainText] Txt.Text :> PostCreated '[PlainText] Txt.Text - -- delivery endpoint for posts of $tag at subscribing instance - :<|> "tags" :> Capture "hashtag" Txt.Text :> "subscribe" :> Header "Origin" Txt.Text :> Get '[PlainText] Integer - -- endpoint for subscribing the instance specified in - -- the Origin header to $hashtag. - -- Returns subscription lease time in seconds. - :<|> "tags" :> Capture "hashtag" Txt.Text :> "unsubscribe" :> Header "Origin" Txt.Text :> Get '[PlainText] Txt.Text - -- endpoint for unsubscribing the instance specified in - -- the Origin header to $hashtag - - postServer :: DHT d => PostService d -> Server PostServiceAPI postServer service = relayInbox service :<|> subscriptionDelivery service @@ -181,24 +177,27 @@ postServer service = relayInbox service :<|> tagUnsubscribe service -relayInbox :: DHT d => PostService d -> Hashtag -> Txt.Text -> Handler NoContent +-- | delivery endpoint: receive posts of a handled tag and enqueue them for relaying +relayInbox :: DHT d => PostService d -> Hashtag -> Text -> Handler NoContent relayInbox serv tag posts = do let -- skip checking whether the post actually contains the tag, just drop full post postIDs = head . Txt.splitOn "," <$> Txt.lines posts -- if tag is not in own responsibility, return a 410 Gone - responsible <- liftIO $ isResponsibleFor (baseDHT serv) (genKeyID . Txt.unpack $ tag) + responsible <- liftIO $ isResponsibleFor (baseDHT serv) (hashtagToId tag) if responsible then pure () else - (throwError $ err410 { errBody = "Relay is not responsible for this tag"}) + throwError $ err410 { errBody = "Relay is not responsible for this tag"} broadcastChan <- liftIO $ atomically $ getTagBroadcastChannel serv tag maybe -- if noone subscribed to the tag, nothing needs to be done (pure ()) -- otherwise enqueue posts into broadcast queue of the tag - (\queue -> + (\queue -> do liftIO $ forM_ postIDs (atomically . writeTChan queue) + -- report the received post for statistic purposes + liftIO . atomically . writeTQueue (statsQueue serv) $ StatsEvent RelayReceiveEvent (length postIDs) (hashtagToId tag) ) broadcastChan pure NoContent @@ -209,7 +208,8 @@ newtype UnhandledTagException = UnhandledTagException String instance Exception UnhandledTagException -subscriptionDelivery :: DHT d => PostService d -> Integer -> Txt.Text -> Handler Txt.Text +-- | delivery endpoint: receives a list of subscribers of tags and their outstanding queues for migration +subscriptionDelivery :: DHT d => PostService d -> Integer -> Text -> Handler Text subscriptionDelivery serv senderID subList = do let tagSubs = Txt.lines subList @@ -221,7 +221,7 @@ subscriptionDelivery serv senderID subList = do -- not-handled tag occurs, this results in a single large transaction. -- Hopefully the performance isn't too bad. res <- liftIO . atomically $ (foldM (\_ tag' -> do - responsible <- isResponsibleForSTM (baseDHT serv) (genKeyID . Txt.unpack $ tag') + responsible <- isResponsibleForSTM (baseDHT serv) (hashtagToId tag') if responsible then processTag (subscribers serv) tag' else throwSTM $ UnhandledTagException (Txt.unpack tag' <> " not handled by this relay") @@ -243,7 +243,7 @@ subscriptionDelivery serv senderID subList = do Right _ -> pure "" -- TODO: check and only accept tags in own (future?) responsibility where - processTag :: TVar RelayTags -> Txt.Text -> STM () + processTag :: TVar RelayTags -> Text -> STM () processTag subscriberSTM tagData = do let tag:subText:lease:posts:_ = Txt.splitOn "," tagData @@ -254,57 +254,62 @@ subscriptionDelivery serv senderID subList = do enqueueSubscription subscriberSTM (normaliseTag tag) sub postList leaseTime -postFetch :: PostService d -> Txt.Text -> Handler Txt.Text -postFetch serv postID = do - postSet <- liftIO . readTVarIO . ownPosts $ serv - if HSet.member postID postSet - -- decision: always return the same placeholder post - then pure placeholderPost - else throwError $ err404 { errBody = "No post found with this ID" } +-- | endpoint for fetching a post by its ID +postFetch :: PostService d -> Text -> Handler Text +postFetch serv _ = do + -- decision: for saving memory do not store published posts, just + -- pretend there is a post for each requested ID + liftIO . atomically . writeTQueue (statsQueue serv) $ StatsEvent IncomingPostFetchEvent 1 0 -- tag fetched for is irrelevant + pure placeholderPost -postMultiFetch :: PostService d -> Txt.Text -> Handler Txt.Text +-- | endpoint for fetching multiple posts of this instance by their IDs +postMultiFetch :: PostService d -> Text -> Handler Text postMultiFetch serv postIDs = do - let idList = Txt.lines postIDs - postSet <- liftIO . readTVarIO . ownPosts $ serv - -- look up existence of all given post IDs, fail if even one is missing - foldM (\response postID -> - if HSet.member postID postSet - then pure $ placeholderPost <> "\n" <> response - else throwError $ err404 { errBody = "No post found with this ID" } + let + idList = Txt.lines postIDs + -- decision: for saving memory do not store published posts, just + -- pretend there is a post for each requested ID + response = foldl (\response' _ -> + placeholderPost <> "\n" <> response' ) "" idList + liftIO . atomically . writeTQueue (statsQueue serv) $ StatsEvent IncomingPostFetchEvent (length idList) 0 -- tag fetched for is irrelevant + pure response -postInbox :: PostService d -> Txt.Text -> Handler NoContent +-- | delivery endpoint: inbox for initially publishing a post at an instance +postInbox :: PostService d -> Text -> Handler NoContent postInbox serv post = do -- extract contained hashtags let containedTags = fmap (normaliseTag . Txt.tail) . filter ((==) '#' . Txt.head) . Txt.words $ post -- generate post ID postId <- liftIO $ Txt.pack . show <$> (randomRIO (0, 2^(128::Integer)-1) :: IO Integer) - -- add ID to own posts - liftIO . atomically $ modifyTVar' (ownPosts serv) (HSet.insert postId) + -- decision: for saving memory do not store published post IDs, just deliver a post for any requested ID -- enqueue a relay job for each tag - liftIO $ forM_ (containedTags :: [Txt.Text]) (\tag -> + liftIO $ forM_ (containedTags :: [Text]) (\tag -> atomically $ writeTQueue (relayInQueue serv) (tag, postId, post) ) pure NoContent -tagDelivery :: PostService d -> Txt.Text -> Txt.Text -> Handler Txt.Text +-- | delivery endpoint: receive postIDs of a certain subscribed hashtag +tagDelivery :: PostService d -> Text -> Text -> Handler Text tagDelivery serv hashtag posts = do let postIDs = Txt.lines posts subscriptions <- liftIO . readTVarIO . ownSubscriptions $ serv - if isJust (HMap.lookup (genKeyID . Txt.unpack $ hashtag) subscriptions) + if isJust (HMap.lookup (hashtagToId hashtag) subscriptions) then -- TODO: increase a counter/ statistics for received posts of this tag liftIO $ forM_ postIDs $ atomically . writeTQueue (postFetchQueue serv) else -- silently drop posts from unsubscribed tags pure () pure $ "Received a postID for tag " <> hashtag -tagSubscribe :: DHT d => PostService d -> Txt.Text -> Maybe Txt.Text -> Handler Integer + +-- | receive subscription requests to a handled hashtag +tagSubscribe :: DHT d => PostService d -> Text -> Maybe Text -> Handler Integer tagSubscribe serv hashtag origin = do - responsible <- liftIO $ isResponsibleFor (baseDHT serv) (genKeyID . Txt.unpack $ hashtag) + responsible <- liftIO $ isResponsibleFor (baseDHT serv) (hashtagToId hashtag) if not responsible -- GONE if not responsible then throwError err410 { errBody = "not responsible for this tag" } @@ -318,12 +323,14 @@ tagSubscribe serv hashtag origin = do let leaseTime = now + confSubscriptionExpiryTime (serviceConf serv) -- setup subscription entry _ <- liftIO . atomically $ setupSubscriberChannel (subscribers serv) hashtag (BSU.toString $ HTTP.host req, HTTP.port req) leaseTime + --liftIO . putStrLn $ "just got a subscription to " <> Txt.unpack hashtag pure $ round leaseTime -tagUnsubscribe :: DHT d => PostService d -> Txt.Text -> Maybe Txt.Text -> Handler Txt.Text +-- | receive and handle unsubscription requests regarding a handled tag +tagUnsubscribe :: DHT d => PostService d -> Text -> Maybe Text -> Handler Text tagUnsubscribe serv hashtag origin = do - responsible <- liftIO $ isResponsibleFor (baseDHT serv) (genKeyID . Txt.unpack $ hashtag) + responsible <- liftIO $ isResponsibleFor (baseDHT serv) (hashtagToId hashtag) if not responsible -- GONE if not responsible then throwError err410 { errBody = "not responsible for this tag" } @@ -341,8 +348,15 @@ tagUnsubscribe serv hashtag origin = do clientAPI :: Proxy PostServiceAPI clientAPI = Proxy - -relayInboxClient :<|> subscriptionDeliveryClient :<|> postFetchClient :<|> postMultiFetchClient :<|> postInboxClient :<|> tagDeliveryClient :<|> tagSubscribeClient :<|> tagUnsubscribeClient = client clientAPI +relayInboxClient + :<|> subscriptionDeliveryClient + :<|> postFetchClient + :<|> postMultiFetchClient + :<|> postInboxClient + :<|> tagDeliveryClient + :<|> tagSubscribeClient + :<|> tagUnsubscribeClient + = client clientAPI -- | Deliver the subscriber list of all hashtags in the interval [fromTag, toTag] @@ -355,7 +369,7 @@ clientDeliverSubscriptions :: PostService d -> (String, Int) -- ^ hostname and port of instance to deliver to -> IO (Either String ()) -- Either signals success or failure clientDeliverSubscriptions serv fromNode fromKey toKey (toHost, toPort) = do - -- collect tag intearval + -- collect tag interval intervalTags <- takeRMapSuccessorsFromTo fromKey toKey <$> readTVarIO (subscribers serv) -- returns a [ (TagSubscribersSTM, TChan PostID, Hashtag) ] -- extract subscribers and posts @@ -385,7 +399,7 @@ clientDeliverSubscriptions serv fromNode fromKey toKey (toHost, toPort) = do Right _ -> do atomically $ modifyTVar' (subscribers serv) $ \tagMap -> - foldr deleteRMapEntry tagMap ((\(_, _, t) -> genKeyID . Txt.unpack $ t) <$> intervalTags) + foldr deleteRMapEntry tagMap ((\(_, _, t) -> hashtagToId t) <$> intervalTags) pure . Right $ () where channelGetAll :: TChan a -> STM [a] @@ -396,7 +410,8 @@ clientDeliverSubscriptions serv fromNode fromKey toKey (toHost, toPort) = do maybe (pure acc) (\x -> channelGetAll' chan (x:acc)) haveRead --- | Subscribe the client to the given hashtag. On success it returns the given lease time. +-- | Subscribe the client to the given hashtag. On success it returns the given lease time, +-- but also records the subscription in its own data structure. clientSubscribeTo :: DHT d => PostService d -> Hashtag -> IO (Either String Integer) clientSubscribeTo serv tag = do lookupRes <- lookupKey (baseDHT serv) (Txt.unpack tag) @@ -411,9 +426,13 @@ clientSubscribeTo serv tag = do Left (FailureResponse _ fresp) |(HTTPT.statusCode . responseStatusCode $ fresp) == 410 && allowRetry -> do -- responsibility gone, force new lookup newRes <- forceLookupKey (baseDHT serv) (Txt.unpack tag) + --putStrLn $ "failed subscribing to " <> Txt.unpack tag <> " on " <> foundHost doSubscribe newRes False Left err -> pure . Left . show $ err - Right lease -> pure . Right $ lease + Right lease -> do + atomically . modifyTVar' (ownSubscriptions serv) $ HMap.insert (hashtagToId tag) (fromInteger lease) + --putStrLn $ "just subscribed to " <> Txt.unpack tag <> " on " <> foundHost + pure . Right $ lease ) lookupResponse @@ -435,7 +454,9 @@ clientUnsubscribeFrom serv tag = do newRes <- forceLookupKey (baseDHT serv) (Txt.unpack tag) doUnsubscribe newRes False Left err -> pure . Left . show $ err - Right _ -> pure . Right $ () + Right _ -> do + atomically . modifyTVar' (ownSubscriptions serv) $ HMap.delete (hashtagToId tag) + pure . Right $ () ) lookupResponse @@ -445,11 +466,11 @@ clientUnsubscribeFrom serv tag = do -- the post to the responsible relays. -- As the initial publishing isn't done by a specific relay (but *to* a specific relay -- instead), the function does *not* take a PostService as argument. -clientPublishPost :: HTTP.Manager -- for better performance, a shared HTTP manager has to be provided - -> String -- hostname - -> Int -- port - -> PostContent -- post content - -> IO (Either String ()) -- error or success +clientPublishPost :: HTTP.Manager -- ^ for better performance, a shared HTTP manager has to be provided + -> String -- ^ hostname + -> Int -- ^ port + -> PostContent -- ^ post content + -> IO (Either String ()) -- ^ error or success clientPublishPost httpman hostname port postC = do resp <- runClientM (postInboxClient postC) (mkClientEnv httpman (BaseUrl Http hostname port "")) pure . bimap show (const ()) $ resp @@ -492,7 +513,7 @@ setupSubscriberChannel tagMapSTM tag subscriber leaseTime = do broadcastChan <- newBroadcastTChan tagOutChan <- dupTChan broadcastChan newSubMapSTM <- newTVar $ HMap.singleton subscriber (tagOutChan, leaseTime) - writeTVar tagMapSTM $ addRMapEntry (genKeyID . Txt.unpack $ tag) (newSubMapSTM, broadcastChan, tag) tagMap + writeTVar tagMapSTM $ addRMapEntry (hashtagToId tag) (newSubMapSTM, broadcastChan, tag) tagMap pure tagOutChan Just (foundSubMapSTM, broadcastChan, _) -> do -- otherwise use the existing subscriber map @@ -520,7 +541,7 @@ deleteSubscription tagMapSTM tag subscriber = do -- if there are no subscriptions for the tag anymore, remove its -- data sttructure altogether if HMap.null newSubMap - then writeTVar tagMapSTM $ deleteRMapEntry (genKeyID . Txt.unpack $ tag) tagMap + then writeTVar tagMapSTM $ deleteRMapEntry (hashtagToId tag) tagMap -- otherwise just remove the subscription of that node else writeTVar foundSubMapSTM newSubMap @@ -541,12 +562,39 @@ getTagBroadcastChannel serv tag = do -- | look up the subscription data of a tag lookupTagSubscriptions :: Hashtag -> RingMap NodeID a -> Maybe a -lookupTagSubscriptions tag = rMapLookup (genKeyID . Txt.unpack $ tag) +lookupTagSubscriptions tag = rMapLookup (hashtagToId tag) --- normalise the unicode representation of a string to NFC -normaliseTag :: Txt.Text -> Txt.Text -normaliseTag = Txt.fromStrict . normalize NFC . Txt.toStrict +-- normalise the unicode representation of a string to NFC and convert to lower case +normaliseTag :: Text -> Text +normaliseTag = Txt.toLower . Txt.fromStrict . normalize NFC . Txt.toStrict + + +-- | convert a hashtag to its representation on the DHT +hashtagToId :: Hashtag -> NodeID +hashtagToId = genKeyID . Txt.unpack + + +readUpToTChan :: Int -> TChan a -> STM [a] +readUpToTChan 0 _ = pure [] +readUpToTChan n chan = do + readFromChan <- tryReadTChan chan + case readFromChan of + Nothing -> pure [] + Just val -> do + moreReads <- readUpToTChan (pred n) chan + pure (val:moreReads) + + +readUpToTQueue :: Int -> TQueue a -> STM [a] +readUpToTQueue 0 _ = pure [] +readUpToTQueue n q = do + readFromQueue <- tryReadTQueue q + case readFromQueue of + Nothing -> pure [] + Just val -> do + moreReads <- readUpToTQueue (pred n) q + pure (val:moreReads) -- | define how to convert all showable types to PlainText -- No idea what I'm doing with these overlappable instances though ¯\_(ツ)_/¯ @@ -559,28 +607,78 @@ instance {-# OVERLAPPABLE #-} Read a => MimeUnrender PlainText a where -- ====== worker threads ====== +-- TODO: make configurable +numParallelDeliveries = 10 + +launchWorkerThreads :: DHT d => PostService d -> IO () +launchWorkerThreads serv = concurrently_ + (processIncomingPosts serv) + $ concurrently_ + (purgeSubscriptionsThread serv) + $ concurrently_ + (fetchTagPosts serv) + (relayWorker serv) + + +-- | periodically remove expired subscription entries from relay subscribers +purgeSubscriptionsThread :: PostService d -> IO () +purgeSubscriptionsThread serv = forever $ do + -- read config + now <- getPOSIXTime + let + purgeInterval = confSubscriptionExpiryTime (serviceConf serv) / 10 + -- no need to atomically lock this, as newly incoming subscriptions do not + -- need to be purged + tagMap <- readTVarIO $ subscribers serv + forM_ tagMap $ \(subscriberMapSTM, _, _) -> + -- but each subscriberMap needs to be modified atomically + atomically . modifyTVar' subscriberMapSTM $ HMap.filter (\(_, ts) -> ts > now) + threadDelay $ fromEnum purgeInterval `div` 10^6 + + -- | process the pending relay inbox of incoming posts from the internal queue: -- Look up responsible relay node for given hashtag and forward post to it processIncomingPosts :: DHT d => PostService d -> IO () processIncomingPosts serv = forever $ do -- blocks until available - -- TODO: process multiple in parallel - (tag, pID, pContent) <- atomically . readTQueue $ relayInQueue serv - lookupRes <- lookupKey (baseDHT serv) (Txt.unpack tag) - case lookupRes of - -- no vserver active => wait and retry - Nothing -> threadDelay $ 10 * 10^6 - Just (responsibleHost, responsiblePort) -> do - resp <- runClientM (relayInboxClient tag $ pID <> "," <> pContent) (mkClientEnv (httpMan serv) (BaseUrl Http responsibleHost (fromIntegral responsiblePort) "")) - case resp of - Left err -> do - putStrLn $ "Error: " <> show err - -- 410 error indicates outdated responsibility mapping - -- Simplification: just invalidate the mapping entry on all errors, force a re-lookup and re-queue the post - -- TODO: keep track of maximum retries - _ <- forceLookupKey (baseDHT serv) (Txt.unpack tag) - atomically . writeTQueue (relayInQueue serv) $ (tag, pID, pContent) - Right yay -> putStrLn $ "Yay! " <> show yay + deliveriesToProcess <- atomically $ do + readResult <- readUpToTQueue numParallelDeliveries $ relayInQueue serv + if null readResult + then retry + else pure readResult + runningJobs <- forM deliveriesToProcess $ \(tag, pID, pContent) -> async $ do + let pIdUri = "http://" <> (Txt.pack . confServiceHost . serviceConf $ serv) <> ":" <> (fromString . show . confServicePort . serviceConf $ serv) <> "/post/" <> pID + lookupRes <- lookupKey (baseDHT serv) (Txt.unpack tag) + case lookupRes of + -- no vserver active => wait and retry + Nothing -> threadDelay (10 * 10^6) >> pure (Left "no vserver active") + Just (responsibleHost, responsiblePort) -> do + resp <- runClientM (relayInboxClient tag $ pIdUri <> "," <> pContent) (mkClientEnv (httpMan serv) (BaseUrl Http responsibleHost (fromIntegral responsiblePort) "")) + case resp of + Left err -> do + -- 410 error indicates outdated responsibility mapping + -- Simplification: just invalidate the mapping entry on all errors, force a re-lookup and re-queue the post + -- TODO: keep track of maximum retries + _ <- forceLookupKey (baseDHT serv) (Txt.unpack tag) + atomically . writeTQueue (relayInQueue serv) $ (tag, pID, pContent) + pure . Left $ "Error: " <> show err + Right _ -> do + -- idea for the experiment: each post publication makes the initial posting instance subscribe to all contained tags + now <- getPOSIXTime + subscriptionStatus <- HMap.lookup (hashtagToId tag) <$> readTVarIO (ownSubscriptions serv) + -- if not yet subscribed or subscription expires within 5 minutes, (re)subscribe to tag + when (maybe True (\subLease -> now - subLease < 300) subscriptionStatus) $ + void $ clientSubscribeTo serv tag + + -- for evaluation, return the tag of the successfully forwarded post + pure $ Right tag + + -- collect async results + results <- mapM waitCatch runningJobs + -- report the count of published posts for statistics + atomically . writeTQueue (statsQueue serv) $ StatsEvent PostPublishEvent (length . rights $ results) 0 -- hashtag published to doesn't matter + pure () + -- | process the pending fetch jobs of delivered post IDs: Delivered posts are tried to be fetched from their URI-ID @@ -590,18 +688,197 @@ fetchTagPosts serv = forever $ do -- TODO: batching, retry -- TODO: process multiple in parallel pIdUri <- atomically . readTQueue $ postFetchQueue serv - fetchReq <- HTTP.parseRequest . Txt.unpack $pIdUri + fetchReq <- HTTP.parseRequest . Txt.unpack $ pIdUri resp <- try $ HTTP.httpLbs fetchReq (httpMan serv) :: IO (Either HTTP.HttpException (HTTP.Response BSUL.ByteString)) case resp of Right response -> - if HTTPT.statusCode (HTTP.responseStatus response) == 200 - then - -- success, TODO: statistics - putStrLn "post fetch success" - else - -- TODO error handling, retry - pure () + -- TODO error handling, retry + --if HTTPT.statusCode (HTTP.responseStatus response) == 200 + -- then + -- -- success, TODO: statistics + -- else + pure () Left _ -> -- TODO error handling, retry pure () + +relayWorker :: PostService d -> IO () +relayWorker serv = forever $ do + -- atomically (to be able to retry) fold a list of due delivery actions + jobsToProcess <- atomically $ do + subscriptionMap <- readTVar $ subscribers serv + jobList <- D.toList <$> foldM (\jobAcc (subscriberMapSTM, _, tag) -> do + subscriberMap <- readTVar subscriberMapSTM + foldM (\jobAcc' ((subHost, subPort), (postChan, _)) -> do + postsToDeliver <- readUpToTChan 500 postChan + let postDeliveryAction = runClientM (tagDeliveryClient tag (Txt.unlines postsToDeliver)) (mkClientEnv (httpMan serv) (BaseUrl Http subHost (fromIntegral subPort) "")) + -- append relay push job to job list + pure $ if not (null postsToDeliver) + then jobAcc' `D.snoc` (do + deliveryResult <- postDeliveryAction + either + (const $ pure ()) + -- on successful push, record that event for statistics + (const . atomically . writeTQueue (statsQueue serv) $ StatsEvent RelayDeliveryEvent (length postsToDeliver) (hashtagToId tag)) + deliveryResult + pure deliveryResult + ) + else jobAcc' + ) jobAcc $ HMap.toList subscriberMap + ) D.empty subscriptionMap + -- if no relay jobs, then retry + if null jobList + then retry + else pure jobList + + -- when processing the list, send several deliveries in parallel + forM_ (chunksOf numParallelDeliveries jobsToProcess) $ \jobset -> do + runningJobs <- mapM async jobset + -- so far just dropping failed attempts, TODO: retry mechanism + results <- mapM waitCatch runningJobs + let + successfulResults = rights results + unsuccessfulResults = lefts results + unless (null unsuccessfulResults) $ putStrLn ("ERR: " <> show (length unsuccessfulResults) <> " failed deliveries!") + putStrLn $ "successfully relayed " <> show (length successfulResults) + pure () + + +-- ======= statistics/measurement and logging ======= + +data StatsEventType = PostPublishEvent + | RelayReceiveEvent + | RelayDeliveryEvent + | IncomingPostFetchEvent + deriving (Enum, Show, Eq) + +-- | Represents measurement event of a 'StatsEventType' with a count relevant for a certain key +data StatsEvent = StatsEvent StatsEventType Int NodeID + deriving (Show, Eq) + + +-- | measured rates of relay performance +-- TODO: maybe include other metrics in here as well, like number of subscribers? +data RelayStats = RelayStats + { relayReceiveRates :: RingMap NodeID Double + -- ^ rate of incoming posts in the responsibility of this relay + , relayDeliveryRates :: RingMap NodeID Double + -- ^ rate of relayed outgoing posts + , postFetchRate :: Double -- no need to differentiate between tags + -- ^ number of post-fetches delivered + , postPublishRate :: Double + -- ^ rate of initially publishing posts through this instance + } + deriving (Show, Eq) + + + +launchStatsThreads :: PostService d -> IO () +launchStatsThreads serv = do + -- create shared accumulator + sharedAccum <- newTVarIO emptyStats + concurrently_ + (accumulateStatsThread sharedAccum $ statsQueue serv) + (evaluateStatsThread serv sharedAccum) + + +-- | Read stats events from queue and add them to a shared accumulator. +-- Instead of letting the events accumulate in the queue and allocate linear memory, immediately fold the result. +accumulateStatsThread :: TVar RelayStats -> TQueue StatsEvent -> IO () +accumulateStatsThread statsAccumulator statsQ = forever $ do + -- blocks until stats event arrives + event <- atomically $ readTQueue statsQ + -- add the event number to current accumulator + atomically $ modifyTVar' statsAccumulator $ statsAdder event + + +-- | add incoming stats events to accumulator value +statsAdder :: StatsEvent -> RelayStats -> RelayStats +statsAdder event stats = case event of + StatsEvent PostPublishEvent num _ -> + stats {postPublishRate = fromIntegral num + postPublishRate stats} + StatsEvent RelayReceiveEvent num key -> + stats {relayReceiveRates = sumIfEntryExists key (fromIntegral num) (relayReceiveRates stats)} + StatsEvent RelayDeliveryEvent num key -> + stats {relayDeliveryRates = sumIfEntryExists key (fromIntegral num) (relayDeliveryRates stats)} + StatsEvent IncomingPostFetchEvent num _ -> + stats {postFetchRate = fromIntegral num + postFetchRate stats} + where + sumIfEntryExists = addRMapEntryWith (\newVal oldVal -> + let toInsert = fromJust $ extractRingEntry newVal + in + case oldVal of + KeyEntry n -> KeyEntry (n + toInsert) + ProxyEntry pointer (Just (KeyEntry n)) -> ProxyEntry pointer (Just (KeyEntry $ n + toInsert)) + ProxyEntry pointer Nothing -> ProxyEntry pointer (Just newVal) + _ -> error "RingMap nested too deeply" + ) + + +-- Periodically exchange the accumulated statistics with empty ones, evaluate them +-- and make them the current statistics of the service. +evaluateStatsThread :: PostService d -> TVar RelayStats -> IO () +evaluateStatsThread serv statsAcc = getPOSIXTime >>= loop + where + loop previousTs = do + threadDelay $ confStatsEvalDelay (serviceConf serv) + -- get and reset the stats accumulator + summedStats <- atomically $ do + stats <- readTVar statsAcc + writeTVar statsAcc emptyStats + pure stats + -- as the transaction might retry several times, current time needs to + -- be read afterwards + now <- getPOSIXTime + -- evaluate stats rate and replace server stats + -- persistently store in a TVar so it can be retrieved later by the DHT + let timePassed = (now - previousTs) * fromIntegral (confSpeedupFactor $ serviceConf serv) + rateStats = evaluateStats timePassed summedStats + atomically $ writeTVar (loadStats serv) rateStats + -- and now what? write a log to file + -- format: total relayReceiveRates;total relayDeliveryRates;postFetchRate;postPublishRate; subscriberSum + -- later: current (reported) load, target load + subscriberSum <- sumSubscribers + TxtI.hPutStrLn (logFileHandle serv) $ + format (fixed 9 % ";" % fixed 20 % ";" % fixed 20 % ";" % fixed 20 % ";" % fixed 20 % ";" % int ) + (realToFrac now :: Double) + (sum . relayReceiveRates $ rateStats) + (sum . relayDeliveryRates $ rateStats) + (postPublishRate rateStats) + (postFetchRate rateStats) + subscriberSum + loop now + + sumSubscribers = do + tagMap <- readTVarIO $ subscribers serv + foldM (\subscriberSum (subscriberMapSTM, _, _) -> do + subscriberMap <- readTVarIO subscriberMapSTM + pure $ subscriberSum + HMap.size subscriberMap + ) + 0 tagMap + + +-- | Evaluate the accumulated statistic events: Currently mostly calculates the event +-- rates by dividing through the collection time frame +evaluateStats :: POSIXTime -> RelayStats -> RelayStats +evaluateStats timeInterval summedStats = + -- first sum all event numbers, then divide through number of seconds passed to + -- get rate per second + RelayStats + { relayReceiveRates = (/ intervalSeconds) <$> relayReceiveRates summedStats + , relayDeliveryRates = (/ intervalSeconds) <$> relayDeliveryRates summedStats + , postPublishRate = postPublishRate summedStats / intervalSeconds + , postFetchRate = postFetchRate summedStats / intervalSeconds + } + where + intervalSeconds = realToFrac timeInterval + + +emptyStats :: RelayStats +emptyStats = RelayStats + { relayReceiveRates = emptyRMap + , relayDeliveryRates = emptyRMap + , postFetchRate = 0 + , postPublishRate = 0 + } diff --git a/src/Hash2Pub/PostService/API.hs b/src/Hash2Pub/PostService/API.hs new file mode 100644 index 0000000..1484631 --- /dev/null +++ b/src/Hash2Pub/PostService/API.hs @@ -0,0 +1,37 @@ +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE InstanceSigs #-} +{-# LANGUAGE MultiParamTypeClasses #-} +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE RankNTypes #-} +{-# LANGUAGE TypeOperators #-} +module Hash2Pub.PostService.API where + +import Data.Text.Lazy (Text) + +import Servant + +type PostServiceAPI = "relay" :> "inbox" :> Capture "hashtag" Text :> ReqBody '[PlainText] Text :> PutCreated '[PlainText] NoContent + -- delivery endpoint at responsible relay for delivering posts of $tag for distribution + :<|> "relay" :> "subscribers" :> Capture "senderID" Integer :> ReqBody '[PlainText] Text :> PostNoContent '[PlainText] Text + -- endpoint for delivering the subscriptions and outstanding queue + :<|> "post" :> Capture "postid" Text :> Get '[PlainText] Text + -- fetch endpoint for posts, full post ID is http://$domain/post/$postid + :<|> "posts" :> ReqBody '[PlainText] Text :> Post '[PlainText] Text + -- endpoint for fetching multiple posts at once + :<|> "posts" :> "inbox" :> ReqBody '[PlainText] Text :> PutCreated '[PlainText] NoContent + -- delivery endpoint of newly published posts of the relay's instance + :<|> "tags" :> Capture "hashtag" Text :> ReqBody '[PlainText] Text :> PostCreated '[PlainText] Text + -- delivery endpoint for posts of $tag at subscribing instance + :<|> "tags" :> Capture "hashtag" Text :> "subscribe" :> Header "Origin" Text :> Get '[PlainText] Integer + -- endpoint for subscribing the instance specified in + -- the Origin header to $hashtag. + -- Returns subscription lease time in seconds. + :<|> "tags" :> Capture "hashtag" Text :> "unsubscribe" :> Header "Origin" Text :> Get '[PlainText] Text + -- endpoint for unsubscribing the instance specified in + -- the Origin header to $hashtag + +-- | needed for guiding type inference +exposedPostServiceAPI :: Proxy PostServiceAPI +exposedPostServiceAPI = Proxy + diff --git a/src/Hash2Pub/ProtocolTypes.hs b/src/Hash2Pub/ProtocolTypes.hs index 86825a7..a5af10c 100644 --- a/src/Hash2Pub/ProtocolTypes.hs +++ b/src/Hash2Pub/ProtocolTypes.hs @@ -1,7 +1,5 @@ module Hash2Pub.ProtocolTypes where -import qualified Data.Map as Map -import Data.Maybe (mapMaybe) import qualified Data.Set as Set import Data.Time.Clock.POSIX (POSIXTime) diff --git a/src/Hash2Pub/RingMap.hs b/src/Hash2Pub/RingMap.hs index e99f8b2..a2fe3ae 100644 --- a/src/Hash2Pub/RingMap.hs +++ b/src/Hash2Pub/RingMap.hs @@ -23,7 +23,30 @@ instance (Bounded k, Ord k, Eq a) => Eq (RingMap k a) where a == b = getRingMap a == getRingMap b instance (Bounded k, Ord k, Show k, Show a) => Show (RingMap k a) where - show rmap = shows "RingMap " (show $ getRingMap rmap) + show rmap = shows ("RingMap " :: String) (show $ getRingMap rmap) + + +instance (Bounded k, Ord k) => Functor (RingMap k) where + -- | map a function over all payload values of a 'RingMap' + fmap f = RingMap . Map.map traversingF . getRingMap + where + traversingF (KeyEntry a) = KeyEntry (f a) + traversingF (ProxyEntry pointer (Just entry)) = ProxyEntry pointer (Just $ traversingF entry) + traversingF (ProxyEntry pointer Nothing) = ProxyEntry pointer Nothing + + +instance (Bounded k, Ord k) => Foldable (RingMap k) where + foldr f initVal = Map.foldr traversingFR initVal . getRingMap + where + traversingFR (KeyEntry a) acc = f a acc + traversingFR (ProxyEntry _ Nothing) acc = acc + traversingFR (ProxyEntry _ (Just entry)) acc = traversingFR entry acc + foldl f initVal = Map.foldl traversingFL initVal . getRingMap + where + traversingFL acc (KeyEntry a) = f acc a + traversingFL acc (ProxyEntry _ Nothing) = acc + traversingFL acc (ProxyEntry _ (Just entry)) = traversingFL acc entry + -- | entry of a 'RingMap' that holds a value and can also -- wrap around the lookup direction at the edges of the name space. @@ -133,7 +156,7 @@ rMapLookupPred :: (Bounded k, Ord k, Num k) rMapLookupPred = lookupWrapper Map.lookupLT Map.lookupLE Backwards addRMapEntryWith :: (Bounded k, Ord k) - => (RingEntry k a -> RingEntry k a -> RingEntry k a) + => (RingEntry k a -> RingEntry k a -> RingEntry k a) -- ^ f new_value mold_value -> k -- ^ key -> a -- ^ value -> RingMap k a @@ -207,7 +230,7 @@ takeEntriesUntil_ :: (Integral i, Bounded k, Ord k) -> Maybe i -- possible number limit -> [a] -> [a] -takeEntriesUntil_ rmap' getterFunc' havingReached previousEntry (Just remaining) takeAcc +takeEntriesUntil_ _rmap' _getterFunc' _havingReached _previousEntry (Just remaining) takeAcc -- length limit reached | remaining <= 0 = takeAcc takeEntriesUntil_ rmap' getterFunc' havingReached previousEntry numLimit takeAcc =