debug messages for skipped discovery

CHANGELOG.md

@@ -1,3 +1,5 @@
+* improve log
+
 ## 1.16.2
 * logged failed discovery refresh in `checkDiscovery` instead of silently swallowing the exception
 * fixed discovery retry rate after a failure: a separate `lastDiscoveryAttempt` timer gates retries by `discoveryInterval()`, so a broken discovery no longer triggers `discover()` on every API request

src/Traits/RequestTrait.php

@@ -334,9 +334,11 @@ protected function checkDiscovery(){
         // failure are gated by lastDiscoveryAttempt so a broken discovery
         // does not get called on every single API request.
         if ($now - $this->lastDiscovery <= $interval) {
+            $this->logger()->debug('YDB: skip discovery by interval.');
             return;
         }
         if ($now - $this->lastDiscoveryAttempt <= $interval) {
+            $this->logger()->debug('YDB: skip discovery by attempt interval.');
             return;
         }