nghttpx: Add --backend-request-buffer option

src/shrpx.cc

@@ -747,6 +747,7 @@ void fill_default_config() {
   mod_config()->listener_disable_timeout = 0.;
   mod_config()->auto_tls_ticket_key = true;
   mod_config()->tls_ctx_per_worker = false;
+  mod_config()->downstream_request_buffer_size = 16 * 1024;
   mod_config()->downstream_response_buffer_size = 64 * 1024;
 }
 } // namespace
@@ -878,6 +879,11 @@ Performance:
               Set maximum number of open files (RLIMIT_NOFILE) to <N>.
               If 0 is given, nghttpx does not set the limit.
               Default: )" << get_config()->rlimit_nofile << R"(
+  --backend-request-buffer=<SIZE>
+              Set buffer size used to store backend request.
+              Default: )"
+      << util::utos_with_unit(get_config()->downstream_request_buffer_size)
+      << R"(
   --backend-response-buffer=<SIZE>
               Set buffer size used to store backend response.
               Default: )"
@@ -1280,6 +1286,7 @@ int main(int argc, char **argv) {
         {"rlimit-nofile", required_argument, &flag, 69},
         {"tls-ctx-per-worker", no_argument, &flag, 70},
         {"backend-response-buffer", required_argument, &flag, 71},
+        {"backend-request-buffer", required_argument, &flag, 72},
         {nullptr, 0, nullptr, 0}};
 
     int option_index = 0;
@@ -1605,6 +1612,10 @@ int main(int argc, char **argv) {
         // --backend-response-buffer
         cmdcfgs.emplace_back(SHRPX_OPT_BACKEND_RESPONSE_BUFFER, optarg);
         break;
+      case 72:
+        // --backend-request-buffer
+        cmdcfgs.emplace_back(SHRPX_OPT_BACKEND_REQUEST_BUFFER, optarg);
+        break;
       default:
         break;
       }

src/shrpx_config.cc

@@ -141,6 +141,7 @@ const char SHRPX_OPT_LISTENER_DISABLE_TIMEOUT[] = "listener-disable-timeout";
 const char SHRPX_OPT_TLS_TICKET_KEY_FILE[] = "tls-ticket-key-file";
 const char SHRPX_OPT_RLIMIT_NOFILE[] = "rlimit-nofile";
 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";
 
 namespace {
@@ -1118,7 +1119,8 @@ int parse_config(const char *opt, const char *optarg) {
     return 0;
   }
 
-  if (util::strieq(opt, SHRPX_OPT_BACKEND_RESPONSE_BUFFER)) {
+  if (util::strieq(opt, SHRPX_OPT_BACKEND_REQUEST_BUFFER) ||
+      util::strieq(opt, SHRPX_OPT_BACKEND_RESPONSE_BUFFER)) {
     size_t n;
     if (parse_uint_with_unit(&n, opt, optarg) != 0) {
       return -1;
@@ -1130,7 +1132,11 @@ int parse_config(const char *opt, const char *optarg) {
       return -1;
     }
 
-    mod_config()->downstream_response_buffer_size = n;
+    if (util::strieq(opt, SHRPX_OPT_BACKEND_REQUEST_BUFFER)) {
+      mod_config()->downstream_request_buffer_size = n;
+    } else {
+      mod_config()->downstream_response_buffer_size = n;
+    }
 
     return 0;
   }

src/shrpx_config.h

@@ -129,6 +129,7 @@ extern const char SHRPX_OPT_LISTENER_DISABLE_TIMEOUT[];
 extern const char SHRPX_OPT_TLS_TICKET_KEY_FILE[];
 extern const char SHRPX_OPT_RLIMIT_NOFILE[];
 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[];
 
 union sockaddr_union {
@@ -257,6 +258,7 @@ struct Config {
   size_t padding;
   size_t worker_frontend_connections;
   size_t rlimit_nofile;
+  size_t downstream_request_buffer_size;
   size_t downstream_response_buffer_size;
   // Bit mask to disable SSL/TLS protocol versions.  This will be
   // passed to SSL_CTX_set_options().

src/shrpx_downstream.cc

@@ -443,7 +443,7 @@ void Downstream::set_request_http2_expect_body(bool f) {
 
 bool Downstream::request_buf_full() {
   if (dconn_) {
-    return request_buf_.rleft() >= 16384;
+    return request_buf_.rleft() >= get_config()->downstream_request_buffer_size;
   } else {
     return false;
   }