nghttpx: Remove --backend-http2-connection-check option, enable it by default

src/shrpx.cc

@@ -917,7 +917,6 @@ void fill_default_config() {
   mod_config()->downstream_response_buffer_size = 16 * 1024;
   mod_config()->no_server_push = false;
   mod_config()->host_unix = false;
-  mod_config()->http2_downstream_connchk = false;
   mod_config()->http2_downstream_connections_per_worker = 0;
 }
 } // namespace
@@ -1220,10 +1219,6 @@ HTTP/2 and SPDY:
               connection to 2**<N>-1.
               Default: )"
       << get_config()->http2_downstream_connection_window_bits << R"(
-  --backend-http2-connection-check
-              Check   HTTP/2  backend   connection  is   alive  before
-              forwarding request.   This option is useful  in unstable
-              network environment (e.g. mobile).
   --backend-no-tls
               Disable SSL/TLS on backend connections.
   --http2-no-cookie-crumbling
@@ -1496,7 +1491,6 @@ int main(int argc, char **argv) {
         {"backend-request-buffer", required_argument, &flag, 72},
         {"no-host-rewrite", no_argument, &flag, 73},
         {"no-server-push", no_argument, &flag, 74},
-        {"backend-http2-connection-check", no_argument, &flag, 75},
         {"backend-http2-connections-per-worker", required_argument, &flag, 76},
         {nullptr, 0, nullptr, 0}};
 
@@ -1835,10 +1829,6 @@ int main(int argc, char **argv) {
         // --no-server-push
         cmdcfgs.emplace_back(SHRPX_OPT_NO_SERVER_PUSH, "yes");
         break;
-      case 75:
-        // --backend-http2-connection-check
-        cmdcfgs.emplace_back(SHRPX_OPT_BACKEND_HTTP2_CONNECTION_CHECK, "yes");
-        break;
       case 76:
         // --backend-http2-connections-per-worker
         cmdcfgs.emplace_back(SHRPX_OPT_BACKEND_HTTP2_CONNECTIONS_PER_WORKER,

src/shrpx_config.cc

@@ -146,8 +146,6 @@ const char SHRPX_OPT_TLS_CTX_PER_WORKER[] = "tls-ctx-per-worker";
 const char SHRPX_OPT_BACKEND_REQUEST_BUFFER[] = "backend-request-buffer";
 const char SHRPX_OPT_BACKEND_RESPONSE_BUFFER[] = "backend-response-buffer";
 const char SHRPX_OPT_NO_SERVER_PUSH[] = "no-server-push";
-const char SHRPX_OPT_BACKEND_HTTP2_CONNECTION_CHECK[] =
-    "backend-http2-connection-check";
 const char SHRPX_OPT_BACKEND_HTTP2_CONNECTIONS_PER_WORKER[] =
     "backend-http2-connections-per-worker";
 
@@ -1197,12 +1195,6 @@ int parse_config(const char *opt, const char *optarg) {
     return 0;
   }
 
-  if (util::strieq(opt, SHRPX_OPT_BACKEND_HTTP2_CONNECTION_CHECK)) {
-    mod_config()->http2_downstream_connchk = util::strieq(optarg, "yes");
-
-    return 0;
-  }
-
   if (util::strieq(opt, SHRPX_OPT_BACKEND_HTTP2_CONNECTIONS_PER_WORKER)) {
     return parse_uint(&mod_config()->http2_downstream_connections_per_worker,
                       opt, optarg);

src/shrpx_config.h

@@ -136,7 +136,6 @@ extern const char SHRPX_OPT_TLS_CTX_PER_WORKER[];
 extern const char SHRPX_OPT_BACKEND_REQUEST_BUFFER[];
 extern const char SHRPX_OPT_BACKEND_RESPONSE_BUFFER[];
 extern const char SHRPX_OPT_NO_SERVER_PUSH[];
-extern const char SHRPX_OPT_BACKEND_HTTP2_CONNECTION_CHECK[];
 extern const char SHRPX_OPT_BACKEND_HTTP2_CONNECTIONS_PER_WORKER[];
 
 union sockaddr_union {
@@ -325,7 +324,6 @@ struct Config {
   bool no_server_push;
   // true if host contains UNIX domain socket path
   bool host_unix;
-  bool http2_downstream_connchk;
 };
 
 const Config *get_config();

src/shrpx_http2_session.cc

@@ -1468,9 +1468,6 @@ void Http2Session::start_checking_connection() {
 }
 
 void Http2Session::reset_connection_check_timer(ev_tstamp t) {
-  if (!get_config()->http2_downstream_connchk) {
-    return;
-  }
   connchk_timer_.repeat = t;
   ev_timer_again(conn_.loop, &connchk_timer_);
 }