diff --git a/dbms/src/IO/ReadBufferFromS3.cpp b/dbms/src/IO/ReadBufferFromS3.cpp
index fef458bf70d..6a69ee82dca 100644
--- a/dbms/src/IO/ReadBufferFromS3.cpp
+++ b/dbms/src/IO/ReadBufferFromS3.cpp
@@ -24,6 +24,8 @@ ReadBufferFromS3::ReadBufferFromS3(Poco::URI uri_,
     Poco::Net::HTTPResponse response;
     std::unique_ptr<Poco::Net::HTTPRequest> request;
 
+    LOG_DEBUG(&Poco::Logger::get("DebugLogger"), "???? " + uri.toString() + " ????");
+
     for (int i = 0; i < DEFAULT_S3_MAX_FOLLOW_GET_REDIRECT; ++i)
     {
         // With empty path poco will send "POST  HTTP/1.1" its bug.
@@ -52,6 +54,7 @@ ReadBufferFromS3::ReadBufferFromS3(Poco::URI uri_,
             break;
 
         uri = location_iterator->second;
+        LOG_DEBUG(&Poco::Logger::get("DebugLogger"), "!!!! " + uri.toString() + "!!!!");
         remote_host_filter.checkURL(uri);
         session = makeHTTPSession(uri, timeouts);
     }
diff --git a/dbms/src/IO/WriteBufferFromS3.cpp b/dbms/src/IO/WriteBufferFromS3.cpp
index e18270946c5..ae7b33ae4ea 100644
--- a/dbms/src/IO/WriteBufferFromS3.cpp
+++ b/dbms/src/IO/WriteBufferFromS3.cpp
@@ -108,6 +108,7 @@ void WriteBufferFromS3::initiate()
     {
         initiate_uri.addQueryParameter(param.first, param.second);
     }
+    LOG_DEBUG(&Poco::Logger::get("DebugLogger"), "???Write "+ uri.toString() + " ???");
 
     for (int i = 0; i < DEFAULT_S3_MAX_FOLLOW_PUT_REDIRECT; ++i)
     {
@@ -139,6 +140,7 @@ void WriteBufferFromS3::initiate()
             break;
 
         initiate_uri = location_iterator->second;
+        LOG_DEBUG(&Poco::Logger::get("DebugLogger"), "!!!Write " + initiate_uri.toString() + " !!!");
         remote_host_filter.checkURL(initiate_uri);
     }
     assertResponseIsOk(*request_ptr, response, *istr);