feat: schema cache metrics

PostgREST · Apr 20, 2024 · 91979e3 · 91979e3
1 parent 3c61645
commit 91979e3
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Showing 2 changed files with 9 additions and 4 deletions.
diff --git a/src/PostgREST/Metrics.hs b/src/PostgREST/Metrics.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE NamedFieldPuns #-}
-{-# LANGUAGE NumericUnderscores #-}
 module PostgREST.Metrics
   ( init
   , MetricsState (..)
@@ -21,6 +20,8 @@ data MetricsState = MetricsState
   , poolAvailable        :: Prom.Gauge
   , poolWaiting          :: Prom.Gauge
   , poolMaxSize          :: Prom.Gauge
+  , schemaCacheLoads     :: Prom.Counter
+  , schemaCacheQueryTime :: Prom.Gauge
   }
 
 init :: Int -> IO MetricsState
@@ -29,11 +30,13 @@ init poolMaxSize = do
   available <- Prom.register $ Prom.gauge (Prom.Info "pgrst_db_pool_available" "Available connections in the pool")
   waiting <- Prom.register $ Prom.gauge (Prom.Info "pgrst_db_pool_waiting" "Requests waiting to acquire a pool connection")
   maxSize <- Prom.register $ Prom.gauge (Prom.Info "pgrst_db_pool_max" "Max pool connections")
+  sCacheLoads <- Prom.register $ Prom.counter (Prom.Info "pgrst_schema_cache_loads_total" "The total number of times the schema cache was loaded")
+  sCacheQTime <- Prom.register $ Prom.gauge (Prom.Info "pgrst_schema_cache_query_time_seconds" "The query time in seconds of the last schema cache load")
   Prom.setGauge maxSize (fromIntegral poolMaxSize)
-  pure $ MetricsState timeouts available waiting maxSize
+  pure $ MetricsState timeouts available waiting maxSize sCacheLoads sCacheQTime
 
 observationMetrics :: MetricsState -> ObservationHandler
-observationMetrics MetricsState{poolTimeouts, poolAvailable, poolWaiting} obs = case obs of
+observationMetrics MetricsState{poolTimeouts, poolAvailable, poolWaiting, schemaCacheLoads, schemaCacheQueryTime} obs = case obs of
   (PoolAcqTimeoutObs _) -> do
     Prom.incCounter poolTimeouts
   (HasqlPoolObs (SQL.ConnectionObservation _ status)) -> case status of
@@ -48,6 +51,9 @@ observationMetrics MetricsState{poolTimeouts, poolAvailable, poolWaiting} obs =
     Prom.incGauge poolWaiting
   PoolRequestFullfilled ->
     Prom.decGauge poolWaiting
+  SchemaCacheLoadedObs resTime -> do
+    Prom.incCounter schemaCacheLoads
+    Prom.setGauge schemaCacheQueryTime resTime
   _ ->
     pure ()
 

diff --git a/test/spec/Main.hs b/test/spec/Main.hs
@@ -280,4 +280,3 @@ main = do
   where
     loadSCache pool conf =
       either (panic.show) id <$> P.use pool (HT.transaction HT.ReadCommitted HT.Read $ querySchemaCache conf)
-
Original file line number	Diff line number	Diff line change
Expand Up		@@ -280,4 +280,3 @@ main = do
		where
		loadSCache pool conf =
		either (panic.show) id <$> P.use pool (HT.transaction HT.ReadCommitted HT.Read $ querySchemaCache conf)