Add idle_timeout for URLTest outbound

constant/timeout.go

@@ -3,11 +3,12 @@ package constant
 import "time"
 
 const (
-	TCPTimeout             = 5 * time.Second
-	ReadPayloadTimeout     = 300 * time.Millisecond
-	DNSTimeout             = 10 * time.Second
-	QUICTimeout            = 30 * time.Second
-	STUNTimeout            = 15 * time.Second
-	UDPTimeout             = 5 * time.Minute
-	DefaultURLTestInterval = 1 * time.Minute
+	TCPTimeout                = 5 * time.Second
+	ReadPayloadTimeout        = 300 * time.Millisecond
+	DNSTimeout                = 10 * time.Second
+	QUICTimeout               = 30 * time.Second
+	STUNTimeout               = 15 * time.Second
+	UDPTimeout                = 5 * time.Minute
+	DefaultURLTestInterval    = 3 * time.Minute
+	DefaultURLTestIdleTimeout = 30 * time.Minute
 )