perf(request-id): use proxy_set_header instead of `ngx.req.set_head…

…er` (#11788) Utilize the Nginx directive `proxy_set_header X-Kong-Request-Id $kong_request_id` instead of Lua call `set_header()` can enhance the RPS by ~2% in the testing scenario where no plugins are enabled. KAG-2814
Kong · Oct 20, 2023 · 6a6af6d · 6a6af6d · khcp-gha-bot · Oct 20, 2023
1 parent 57e50d8
commit 6a6af6d
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Showing 2 changed files with 18 additions and 14 deletions.
diff --git a/kong/runloop/handler.lua b/kong/runloop/handler.lua
@@ -44,7 +44,6 @@ local log               = ngx.log
 local exit              = ngx.exit
 local exec              = ngx.exec
 local header            = ngx.header
-local set_header        = ngx.req.set_header
 local timer_at          = ngx.timer.at
 local get_phase         = ngx.get_phase
 local subsystem         = ngx.config.subsystem
@@ -1355,9 +1354,6 @@ return {
     end,
     -- Only executed if the `router` module found a route and allows nginx to proxy it.
     after = function(ctx)
-      local enabled_headers_upstream = kong.configuration.enabled_headers_upstream
-      local headers = constants.HEADERS
-
       -- Nginx's behavior when proxying a request with an empty querystring
       -- `/foo?` is to keep `$is_args` an empty string, hence effectively
       -- stripping the empty querystring.
@@ -1450,16 +1446,6 @@ return {
       if var.http_proxy_connection then
         clear_header("Proxy-Connection")
       end
-
-      -- X-Kong-Request-Id upstream header
-      local rid, rid_get_err = request_id_get()
-      if not rid then
-        log(WARN, "failed to get Request ID: ", rid_get_err)
-      end
-
-      if enabled_headers_upstream[headers.REQUEST_ID] and rid then
-        set_header(headers.REQUEST_ID, rid)
-      end
     end
   },
   header_filter = {

diff --git a/kong/templates/nginx_kong.lua b/kong/templates/nginx_kong.lua
@@ -168,6 +168,9 @@ server {
         proxy_set_header      X-Forwarded-Path   $upstream_x_forwarded_path;
         proxy_set_header      X-Forwarded-Prefix $upstream_x_forwarded_prefix;
         proxy_set_header      X-Real-IP          $remote_addr;
+> if enabled_headers_upstream["X-Kong-Request-Id"] then
+        proxy_set_header      X-Kong-Request-Id  $kong_request_id;
+> end
         proxy_pass_header     Server;
         proxy_pass_header     Date;
         proxy_ssl_name        $upstream_host;
@@ -199,6 +202,9 @@ server {
         proxy_set_header      X-Forwarded-Path   $upstream_x_forwarded_path;
         proxy_set_header      X-Forwarded-Prefix $upstream_x_forwarded_prefix;
         proxy_set_header      X-Real-IP          $remote_addr;
+> if enabled_headers_upstream["X-Kong-Request-Id"] then
+        proxy_set_header      X-Kong-Request-Id  $kong_request_id;
+> end
         proxy_pass_header     Server;
         proxy_pass_header     Date;
         proxy_ssl_name        $upstream_host;
@@ -230,6 +236,9 @@ server {
         proxy_set_header      X-Forwarded-Path   $upstream_x_forwarded_path;
         proxy_set_header      X-Forwarded-Prefix $upstream_x_forwarded_prefix;
         proxy_set_header      X-Real-IP          $remote_addr;
+> if enabled_headers_upstream["X-Kong-Request-Id"] then
+        proxy_set_header      X-Kong-Request-Id  $kong_request_id;
+> end
         proxy_pass_header     Server;
         proxy_pass_header     Date;
         proxy_ssl_name        $upstream_host;
@@ -261,6 +270,9 @@ server {
         proxy_set_header      X-Forwarded-Path   $upstream_x_forwarded_path;
         proxy_set_header      X-Forwarded-Prefix $upstream_x_forwarded_prefix;
         proxy_set_header      X-Real-IP          $remote_addr;
+> if enabled_headers_upstream["X-Kong-Request-Id"] then
+        proxy_set_header      X-Kong-Request-Id  $kong_request_id;
+> end
         proxy_pass_header     Server;
         proxy_pass_header     Date;
         proxy_ssl_name        $upstream_host;
@@ -285,6 +297,9 @@ server {
         grpc_set_header      X-Forwarded-Path   $upstream_x_forwarded_path;
         grpc_set_header      X-Forwarded-Prefix $upstream_x_forwarded_prefix;
         grpc_set_header      X-Real-IP          $remote_addr;
+> if enabled_headers_upstream["X-Kong-Request-Id"] then
+        grpc_set_header      X-Kong-Request-Id  $kong_request_id;
+> end
         grpc_pass_header     Server;
         grpc_pass_header     Date;
         grpc_ssl_name        $upstream_host;
@@ -328,6 +343,9 @@ server {
         proxy_set_header      X-Forwarded-Path   $upstream_x_forwarded_path;
         proxy_set_header      X-Forwarded-Prefix $upstream_x_forwarded_prefix;
         proxy_set_header      X-Real-IP          $remote_addr;
+> if enabled_headers_upstream["X-Kong-Request-Id"] then
+        proxy_set_header      X-Kong-Request-Id  $kong_request_id;
+> end
         proxy_pass_header     Server;
         proxy_pass_header     Date;
         proxy_ssl_name        $upstream_host;