New option to dead server to not retry during dead period

doc/admin-guide/files/records.config.en.rst

@@ -1452,7 +1452,7 @@ Origin Server Connect Attempts
    :reloadable:
    :overridable:
 
-   Maximum number of connection retries |TS| can make while an origin is marked dead.  Typically this value is smaller than
+   Maximum number of connection attempts |TS| can make while an origin is marked dead per request.  Typically this value is smaller than
    `proxy.config.http.connect_attempts_max_retries`_ so an error is returned to the client faster and also to reduce the load on the dead origin.
    The timeout interval `proxy.config.http.connect_attempts_timeout`_ in seconds is used with this setting.
 

proxy/http/HttpSM.cc

@@ -4936,6 +4936,12 @@ HttpSM::do_http_server_open(bool raw)
       call_transact_and_set_next_state(HttpTransact::Forbidden);
       return;
     }
+
+    if (HttpTransact::is_server_negative_cached(&t_state) == true &&
+        t_state.txn_conf->connect_attempts_max_retries_dead_server <= 0) {
+      call_transact_and_set_next_state(HttpTransact::OriginDead);
+      return;
+    }
   }
 
   // Check for self loop.

proxy/http/HttpTransact.cc

@@ -451,7 +451,7 @@ update_cache_control_information_from_config(HttpTransact::State *s)
   }
 }
 
-inline bool
+bool
 HttpTransact::is_server_negative_cached(State *s)
 {
   if (s->host_db_info.app.http_data.last_failure != 0 &&
@@ -865,6 +865,15 @@ HttpTransact::TooEarly(State *s)
   TRANSACT_RETURN(SM_ACTION_SEND_ERROR_CACHE_NOOP, nullptr);
 }
 
+void
+HttpTransact::OriginDead(State *s)
+{
+  TxnDebug("http_trans", "origin server is marked down");
+  bootstrap_state_variables_from_request(s, &s->hdr_info.client_request);
+  build_error_response(s, HTTP_STATUS_BAD_GATEWAY, "Origin Server Marked Down", "connect#failed_connect");
+  TRANSACT_RETURN(SM_ACTION_SEND_ERROR_CACHE_NOOP, nullptr);
+}
+
 void
 HttpTransact::HandleBlindTunnel(State *s)
 {
@@ -3770,12 +3779,14 @@ HttpTransact::handle_response_from_server(State *s)
     }
 
     if (is_server_negative_cached(s)) {
-      max_connect_retries = s->txn_conf->connect_attempts_max_retries_dead_server;
+      max_connect_retries = s->txn_conf->connect_attempts_max_retries_dead_server - 1;
     } else {
       // server not yet negative cached - use default number of retries
       max_connect_retries = s->txn_conf->connect_attempts_max_retries;
     }
 
+    TxnDebug("http_trans", "max_connect_retries: %d s->current.attempts: %d", max_connect_retries, s->current.attempts);
+
     if (is_request_retryable(s) && s->current.attempts < max_connect_retries) {
       // If this is a round robin DNS entry & we're tried configured
       //    number of times, we should try another node

proxy/http/HttpTransact.h

@@ -937,8 +937,9 @@ class HttpTransact
   static void HandleRequestAuthorized(State *s);
   static void BadRequest(State *s);
   static void Forbidden(State *s);
-  static void TooEarly(State *s);
   static void SelfLoop(State *s);
+  static void TooEarly(State *s);
+  static void OriginDead(State *s);
   static void PostActiveTimeoutResponse(State *s);
   static void PostInactiveTimeoutResponse(State *s);
   static void DecideCacheLookup(State *s);