chatdesk-ui/postgrest_v12.2.8/src/PostgREST/Metrics.hs

57 lines
2.2 KiB
Haskell

module PostgREST.Metrics
( init
, MetricsState (..)
, observationMetrics
, metricsToText
) where
import qualified Data.ByteString.Lazy as LBS
import qualified Hasql.Pool.Observation as SQL
import Prometheus
import PostgREST.Observation
import Protolude
data MetricsState =
MetricsState Counter Gauge Gauge Gauge (Vector Label1 Counter) Gauge
init :: Int -> IO MetricsState
init configDbPoolSize = do
poolTimeouts <- register $ counter (Info "pgrst_db_pool_timeouts_total" "The total number of pool connection timeouts")
poolAvailable <- register $ gauge (Info "pgrst_db_pool_available" "Available connections in the pool")
poolWaiting <- register $ gauge (Info "pgrst_db_pool_waiting" "Requests waiting to acquire a pool connection")
poolMaxSize <- register $ gauge (Info "pgrst_db_pool_max" "Max pool connections")
schemaCacheLoads <- register $ vector "status" $ counter (Info "pgrst_schema_cache_loads_total" "The total number of times the schema cache was loaded")
schemaCacheQueryTime <- register $ gauge (Info "pgrst_schema_cache_query_time_seconds" "The query time in seconds of the last schema cache load")
setGauge poolMaxSize (fromIntegral configDbPoolSize)
pure $ MetricsState poolTimeouts poolAvailable poolWaiting poolMaxSize schemaCacheLoads schemaCacheQueryTime
observationMetrics :: MetricsState -> ObservationHandler
observationMetrics (MetricsState poolTimeouts poolAvailable poolWaiting _ schemaCacheLoads schemaCacheQueryTime) obs = case obs of
(PoolAcqTimeoutObs _) -> do
incCounter poolTimeouts
(HasqlPoolObs (SQL.ConnectionObservation _ status)) -> case status of
SQL.ReadyForUseConnectionStatus -> do
incGauge poolAvailable
SQL.InUseConnectionStatus -> do
decGauge poolAvailable
SQL.TerminatedConnectionStatus _ -> do
decGauge poolAvailable
SQL.ConnectingConnectionStatus -> pure ()
PoolRequest ->
incGauge poolWaiting
PoolRequestFullfilled ->
decGauge poolWaiting
SchemaCacheLoadedObs resTime -> do
withLabel schemaCacheLoads "SUCCESS" incCounter
setGauge schemaCacheQueryTime resTime
SchemaCacheErrorObs _ -> do
withLabel schemaCacheLoads "FAIL" incCounter
_ ->
pure ()
metricsToText :: IO LBS.ByteString
metricsToText = exportMetricsAsText