feat: support backlog in listen and if= condition in access_log via nginx_config

apisix/cli/ngx_tpl.lua

@@ -556,9 +556,9 @@ http {
     uninitialized_variable_warn off;
 
     {% if http.access_log_buffer then %}
-    access_log {* http.access_log *} main buffer={* http.access_log_buffer *} flush=3;
+    access_log {* http.access_log *} main buffer={* http.access_log_buffer *} flush=3{% if http.access_log_if then %} if={* http.access_log_if *}{% end %};
     {% else %}
-    access_log {* http.access_log *} main buffer=16384 flush=3;
+    access_log {* http.access_log *} main buffer=16384 flush=3{% if http.access_log_if then %} if={* http.access_log_if *}{% end %};
     {% end %}
     {% end %}
     open_file_cache  max=1000 inactive=60;
@@ -843,7 +843,7 @@ http {
         http3 on;
         {% end %}
         {% for _, item in ipairs(node_listen) do %}
-        listen {* item.ip *}:{* item.port *} default_server {% if enable_reuseport then %} reuseport {% end %};
+        listen {* item.ip *}:{* item.port *} default_server {% if enable_reuseport then %} reuseport {% end %}{% if item.backlog then %} backlog={* item.backlog *}{% end %};
         {% end %}
         {% if ssl.enable then %}
         {% for _, item in ipairs(ssl.listen) do %}

apisix/cli/ops.lua

@@ -524,7 +524,7 @@ Please modify "admin_key" in conf/config.yaml .
     local ip_port_to_check = {}
 
     local function listen_table_insert(listen_table, scheme, ip, port,
-                                enable_http3, enable_ipv6)
+                                enable_http3, enable_ipv6, backlog)
         if type(ip) ~= "string" then
             util.die(scheme, " listen ip format error, must be string", "\n")
         end
@@ -545,7 +545,8 @@ Please modify "admin_key" in conf/config.yaml .
                     {
                         ip = ip,
                         port = port,
-                        enable_http3 = enable_http3
+                        enable_http3 = enable_http3,
+                        backlog = backlog
                     })
             ip_port_to_check[addr] = scheme
         end
@@ -559,7 +560,8 @@ Please modify "admin_key" in conf/config.yaml .
                         {
                             ip = ip,
                             port = port,
-                            enable_http3 = enable_http3
+                            enable_http3 = enable_http3,
+                            backlog = backlog
                         })
                 ip_port_to_check[addr] = scheme
             end
@@ -581,6 +583,7 @@ Please modify "admin_key" in conf/config.yaml .
                 local port = value.port
                 local enable_ipv6 = false
                 local enable_http2 = value.enable_http2
+                local backlog = value.backlog
 
                 if ip == nil then
                     ip = "0.0.0.0"
@@ -599,8 +602,13 @@ Please modify "admin_key" in conf/config.yaml .
                             .. "apisix level.", "\n")
                 end
 
+                if backlog ~= nil and (type(backlog) ~= "number"
+                        or backlog <= 0 or backlog % 1 ~= 0) then
+                    util.die("ERROR: backlog in node_listen must be a positive integer.", "\n")
+                end
+
                 listen_table_insert(node_listen, "http", ip, port,
-                        false, enable_ipv6)
+                        false, enable_ipv6, backlog)
             end
         end
     end

conf/config.yaml.example

@@ -23,6 +23,8 @@ apisix:
   node_listen:                 # APISIX listening ports.
     - 9080
   #   - port: 9081
+  #     backlog: 8192          # Set the `backlog` parameter of the listen directive,
+  #                            # which caps the pending connections queue. Default is 511.
   #   - ip: 127.0.0.2          # If not set, default to `0.0.0.0`
   #     port: 9082
   enable_admin: true           # Admin API
@@ -303,6 +305,12 @@ nginx_config:                     # Config for render the template to generate n
     enable_access_log: true             # Enable HTTP proxy access logging.
     access_log: logs/access.log         # Location of the access log.
     access_log_buffer: 16384            # buffer size of access log.
+  # access_log_if: $loggable            # If set, append an `if=<condition>` parameter to the
+                                        # access_log directive, so requests are logged only when
+                                        # the condition is met (e.g. log sampling or excluding
+                                        # specific status codes / endpoints). The referenced
+                                        # variable must be declared via http_configuration_snippet
+                                        # (e.g. `map` or `split_clients`).
     # available variables:
     # request_type: traditional_http / ai_chat / ai_stream
     # llm_time_to_first_token: duration from the start send request to ai server to the first token received

t/cli/test_access_log.sh

@@ -315,3 +315,41 @@ if ! grep '127.0.0.1 UDP test_stream_access_log_format' output.log; then
     exit 1
 fi
 echo "passed: logs are being dumped for stream proxy"
+
+# check access_log if condition
+
+git checkout conf/config.yaml
+
+echo '
+nginx_config:
+  http:
+    access_log_if: $loggable
+    http_configuration_snippet: |
+      map $status $loggable {
+          default 1;
+      }
+' > conf/config.yaml
+
+make init
+
+count_log_if=$(grep "access_log logs/access.log main buffer=16384 flush=3" conf/nginx.conf | grep -cF 'if=$loggable;' || true)
+if [ "$count_log_if" -ne 1 ]; then
+    echo "failed: access_log if condition is not rendered"
+    exit 1
+fi
+
+echo "passed: access_log if condition is ok"
+
+# check access_log if condition is not rendered by default
+
+git checkout conf/config.yaml
+
+make init
+
+count_no_log_if=$(grep "access_log logs/access.log main" conf/nginx.conf | grep -c "if=" || true)
+if [ "$count_no_log_if" -ne 0 ]; then
+    echo "failed: access_log if condition should not be rendered when it is not configured"
+    exit 1
+fi
+
+echo "passed: access_log if condition is not rendered when it is not configured"

t/cli/test_main.sh

@@ -177,6 +177,54 @@ fi
 
 echo "passed: support specific IP listen in http and https"
 
+# check support backlog in node_listen
+
+git checkout conf/config.yaml
+
+echo "
+apisix:
+  node_listen:
+    - ip: 127.0.0.1
+      port: 9081
+      backlog: 8192
+    - ip: 127.0.0.2
+      port: 9082
+" > conf/config.yaml
+
+make init
+
+count_backlog=`grep "listen 127.0.0.1:9081" conf/nginx.conf | grep -c "backlog=8192" || true`
+if [ $count_backlog -ne 1 ]; then
+    echo "failed: failed to support backlog in node_listen"
+    exit 1
+fi
+
+count_no_backlog=`grep "listen 127.0.0.2:9082" conf/nginx.conf | grep -c "backlog" || true`
+if [ $count_no_backlog -ne 0 ]; then
+    echo "failed: backlog should not be rendered when it is not configured"
+    exit 1
+fi
+
+echo "passed: support backlog in node_listen"
+
+# check invalid backlog in node_listen
+
+echo "
+apisix:
+  node_listen:
+    - ip: 127.0.0.1
+      port: 9081
+      backlog: abc
+" > conf/config.yaml
+
+out=$(make init 2>&1 || true)
+if ! echo "$out" | grep 'backlog in node_listen must be a positive integer'; then
+    echo "failed: failed to detect invalid backlog in node_listen"
+    exit 1
+fi
+
+echo "passed: check invalid backlog in node_listen"
+
 # check deprecated enable_http2 in node_listen
 echo "
 apisix: