diff --git a/CHANGELOG.md b/CHANGELOG.md index e62fa65c56..77cc7a6409 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -8,7 +8,8 @@ This project adheres to [Semantic Versioning](http://semver.org/). ### Added - #1783, Include partitioned tables into the schema cache. Allows embedding, UPSERT, INSERT with Location response, OPTIONS request and OpenAPI support for partitioned tables - @laurenceisla - + - #1878, Add Retry-After hint header when in recovery mode - @gautam1168 + ### Fixed ## [8.0.0] - 2021-07-25 diff --git a/src/PostgREST/App.hs b/src/PostgREST/App.hs index 18c96c6beb..1226aabfe3 100644 --- a/src/PostgREST/App.hs +++ b/src/PostgREST/App.hs @@ -152,13 +152,19 @@ postgrest logLev appState connWorker = runExceptT $ postgrestResponse conf maybeDbStructure jsonDbS pgVer (AppState.getPool appState) time req response <- either Error.errorResponseFor identity <$> eitherResponse - -- Launch the connWorker when the connection is down. The postgrest -- function can respond successfully (with a stale schema cache) before -- the connWorker is done. - when (Wai.responseStatus response == HTTP.status503) connWorker - - respond response + let isPGAway = Wai.responseStatus response == HTTP.status503 + when isPGAway connWorker + resp <- addRetryHint isPGAway appState response + respond resp + +addRetryHint :: Bool -> AppState -> Wai.Response -> IO Wai.Response +addRetryHint shouldAdd appState response = do + delay <- AppState.getRetryNextIn appState + let h = ("Retry-After", BS8.pack $ show delay) + return $ Wai.mapResponseHeaders (\hs -> if shouldAdd then h:hs else hs) response postgrestResponse :: AppConfig diff --git a/src/PostgREST/AppState.hs b/src/PostgREST/AppState.hs index bc9da187e3..964f9b4612 100644 --- a/src/PostgREST/AppState.hs +++ b/src/PostgREST/AppState.hs @@ -10,6 +10,7 @@ module PostgREST.AppState , getPgVersion , getPool , getTime + , getRetryNextIn , init , initWithPool , logWithZTime @@ -18,6 +19,7 @@ module PostgREST.AppState , putIsWorkerOn , putJsonDbS , putPgVersion + , putRetryNextIn , releasePool , signalListener , waitListener @@ -60,6 +62,8 @@ data AppState = AppState , stateGetZTime :: IO ZonedTime -- | Used for killing the main thread in case a subthread fails , stateMainThreadId :: ThreadId + -- | Keeps track of when the next retry for connecting to database is scheduled + , stateRetryNextIn :: IORef Int } init :: AppConfig -> IO AppState @@ -79,6 +83,7 @@ initWithPool newPool conf = <*> mkAutoUpdate defaultUpdateSettings { updateAction = getCurrentTime } <*> mkAutoUpdate defaultUpdateSettings { updateAction = getZonedTime } <*> myThreadId + <*> newIORef 0 initPool :: AppConfig -> IO P.Pool initPool AppConfig{..} = @@ -115,6 +120,12 @@ getIsWorkerOn = readIORef . stateIsWorkerOn putIsWorkerOn :: AppState -> Bool -> IO () putIsWorkerOn = atomicWriteIORef . stateIsWorkerOn +getRetryNextIn :: AppState -> IO Int +getRetryNextIn = readIORef . stateRetryNextIn + +putRetryNextIn :: AppState -> Int -> IO () +putRetryNextIn = atomicWriteIORef . stateRetryNextIn + getConfig :: AppState -> IO AppConfig getConfig = readIORef . stateConf diff --git a/src/PostgREST/Workers.hs b/src/PostgREST/Workers.hs index c282bb5412..3aa19c06d5 100644 --- a/src/PostgREST/Workers.hs +++ b/src/PostgREST/Workers.hs @@ -144,6 +144,7 @@ connectionStatus appState = "Attempting to reconnect to the database in " <> (show delay::Text) <> " seconds..." + when itShould $ AppState.putRetryNextIn appState delay return itShould -- | Load the DbStructure by using a connection from the pool.