diff --git a/src/Yam/Transaction.hs b/src/Yam/Transaction.hs
--- a/src/Yam/Transaction.hs
+++ b/src/Yam/Transaction.hs
@@ -14,6 +14,7 @@
   , DataSourceConnector
   , DataSourceProvider
   , HasDataSource(..)
+  , DataSourceException(..)
   , runTrans
   , selectValue
   , selectNow
@@ -74,7 +75,14 @@
 class HasDataSource ds where
   connector :: MonadTransaction m => Proxy ds -> DataSourceConnector m a
 
-initDataSource :: MonadTransaction m => [DataSourceProvider m a] -> DataSource -> Maybe DataSource -> m a -> m a
+data DataSourceException = DataSourcePoolNotFound Text
+                         | DataSourceNotSupported Text
+                         | DataSourceConfigNotFound Text
+                         deriving Show
+
+instance Exception DataSourceException
+
+initDataSource :: (MonadTransaction m) => [DataSourceProvider m a] -> DataSource -> Maybe DataSource -> m a -> m a
 initDataSource maps ds ds2nd action = let map = M.fromList maps in go map ds ds2nd action
   where go map ds ds2 action = do
           logger <- toMonadLogger
@@ -83,7 +91,7 @@
               Nothing -> setConnectionPool p Nothing >> action
               Just s2 -> getConnector map logger s2 $ \v -> setConnectionPool p (Just v) >> action
         getConnector map logger ds = case M.lookup (dbtype ds) map of
-            Nothing -> error $ "Datasource " <> cs (dbtype ds) <> " not supported"
+            Nothing -> \_ -> throwM $ DataSourceNotSupported $ cs $ dbtype ds
             Just db -> db logger ds
 
 runTrans :: MonadTransaction m => Transaction a -> m a
@@ -95,7 +103,7 @@
 runSecondaryTrans trans = do
   pool <- secondaryPool
   case pool of
-    Nothing -> error "Secondary Pool not exists"
+    Nothing -> throwM $ DataSourcePoolNotFound "Secondary Pool"
     Just p  -> withLoggerName "Backup" $ executePool trans p
 
 class FromPersistValue a where
@@ -118,7 +126,7 @@
         dbNow "sqlite"     = selectValue "SELECT CURRENT_TIMESTAMP"
         dbNow "postgresql" = selectValue "SELECT CURRENT_TIMESTAMP"
         dbNow "oracle"     = selectValue "SELECT SYSDATE FROM DUAL"
-        dbNow dbms         = error $ "Datasource " <> cs dbms <> " not supported"
+        dbNow dbms         = throwM $ DataSourceNotSupported $ cs $ dbms
 
 selectValue :: (PersistField a) => Text -> Transaction [a]
 selectValue sql = fmap unSingle <$> rawSql sql []
diff --git a/yam-app.cabal b/yam-app.cabal
--- a/yam-app.cabal
+++ b/yam-app.cabal
@@ -1,5 +1,5 @@
 name:                yam-app
-version:             0.1.6
+version:             0.1.7
 synopsis:            Yam App
 description:         Base Module for Yam
 homepage:            https://github.com/leptonyu/yam/tree/master/yam-app#readme