BUG#35392531 Recreate CURL connection on retry

In order to avoid issues caused by unexpected CURL states, the CURL
connection is recreated whenever an HTTP(S) request needs to be retried.

Additionally, requests are automatically retried on the following error:
CURLE_OPERATION_TIMEDOUT (28).

Change-Id: I79bf0498a4930ca50b1a96fa32aa506d8f0ace3c
(cherry picked from commit 002c54e50dafb5e3cfc0eacb7333eab3ec8dc60f)

Author: Paweł Andruszkiewicz

mysqlshdk/libs/rest/rest_service.cc

@@ -385,6 +385,10 @@ class Rest_service::Impl {
 
   const Masked_string &base_url() const { return m_base_url; }
 
+  void reset_connection() {
+    m_handle.reset(curl_easy_duphandle(m_handle.get()));
+  }
+
  private:
   void verify_ssl(bool verify) {
     curl_easy_setopt(m_handle.get(), CURLOPT_SSL_VERIFYHOST, verify ? 2L : 0L);
@@ -588,6 +592,7 @@ Response::Status_code Rest_service::execute(Request *request,
   }
 
   const auto retry = [&response, &retry_strategy, this](const char *msg) {
+    m_impl->reset_connection();
     if (response && response->body) response->body->clear();
     retry_strategy->wait_for_retry();
     // this log is to have visibility of the error

mysqlshdk/libs/rest/retry_strategy.cc

@@ -57,6 +57,8 @@ std::unique_ptr<Retry_strategy> default_retry_strategy() {
   // retry in case of partial file error reported by CURL, can happen due to a
   // network error, when received data is shorter than reported
   retry_strategy->add_retriable_error_code(Error_code::PARTIAL_FILE);
+  // retry if operation times out, sometimes servers get stuck...
+  retry_strategy->add_retriable_error_code(Error_code::OPERATION_TIMEDOUT);
 
   // Throttling handling: equal jitter guarantees some wait time before next
   // attempt