Files
postgrest/test/observability/Observation/SchemaCacheSpec.hs
T
Michal KleczekandTaimoor Zaeem abd76ca8ac fix: Flush pool as late as possible during schema cache reloading (#4645)
retryingSchemaCacheLoad flushes the pool upon every retry before it starts reloading the schema. This is too early as schema reloading might take some time during which new connections might be acquired. The consequence is that:
* upon successful schema cache reload we might have some connections created with the old schema cache
* we close connections upon each retry and under load we will keep closing and re-opening connections until schema cache load succeeds

This change is to make sure we flush the pool only after successful schema cache querying but before loading (so that connections acquired during loading wait for it and do not interfere with timing the loading process).
2026-04-16 11:55:43 +05:00

50 lines
2.0 KiB
Haskell

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE MonadComprehensions #-}
{-# LANGUAGE NamedFieldPuns #-}
module Observation.SchemaCacheSpec where
import Network.Wai (Application)
import ObsHelper
import qualified PostgREST.AppState as AppState
import PostgREST.Config (configDbSchemas)
import PostgREST.Observation
import Protolude
import Test.Hspec (SpecWith, describe, it)
import Test.Hspec.Wai (getState)
spec :: SpecWith (SpecState, Application)
spec = describe "Server started with metrics enabled" $ do
it "Should emit PoolFlushed, SchemaCacheQueriedObs and SchemaCacheLoadedObs when schema cache is reloaded" $ do
SpecState{specAppState = appState, specObsChan} <- getState
let waitFor = waitForObs specObsChan
liftIO $ do
AppState.schemaCacheLoader appState
waitFor (1 * sec) "PoolFlushed" $ \x -> [ o | o@PoolFlushed <- pure x ]
waitFor (1 * sec) "SchemaCacheQueriedObs" $ \x -> [ o | o@SchemaCacheQueriedObs{} <- pure x ]
waitFor (1 * sec) "SchemaCacheLoadedObs" $ \x -> [ o | o@SchemaCacheLoadedObs{} <- pure x ]
it "Should flush pool once when schema reloading retries" $ do
SpecState{specAppState = appState, specObsChan} <- getState
let waitFor = waitForObs specObsChan
liftIO $ do
AppState.getConfig appState >>= \cfg -> do
AppState.putConfig appState $ cfg { configDbSchemas = pure "bad_schema" }
AppState.schemaCacheLoader appState
waitFor (1 * sec) "SchemaCacheErrorObs" $ \x -> [ o | o@SchemaCacheErrorObs{} <- pure x ]
-- Restore configuration
AppState.putConfig appState cfg
-- Wait for 2 seconds so that retry can happen
waitFor (2 * sec) "PoolFlushed" $ \x -> [ o | o@PoolFlushed <- pure x ]
waitFor (1 * sec) "SchemaCacheQueriedObs" $ \x -> [ o | o@SchemaCacheQueriedObs{} <- pure x ]
waitFor (1 * sec) "SchemaCacheLoadedObs" $ \x -> [ o | o@SchemaCacheLoadedObs{} <- pure x ]
where
sec = 1000000