bugfix: applied the single_process_graceful_exit patch to the nginx core to fix the issue that nginx fails to perform graceful exit when master_process is turned off.

patches/nginx-1.11.2-single_process_graceful_exit.patch

@@ -0,0 +1,53 @@
+--- nginx-1.11.2/src/os/unix/ngx_process_cycle.c	2016-07-05 08:56:16.000000000 -0700
++++ nginx-1.11.2-patched/src/os/unix/ngx_process_cycle.c	2017-05-14 09:59:52.301108274 -0700
+@@ -304,11 +304,29 @@ ngx_single_process_cycle(ngx_cycle_t *cy
+     }
+ 
+     for ( ;; ) {
++        if (ngx_exiting) {
++            ngx_event_cancel_timers();
++
++            if (ngx_event_timer_rbtree.root == ngx_event_timer_rbtree.sentinel)
++            {
++                ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "exiting");
++
++                for (i = 0; cycle->modules[i]; i++) {
++                    if (cycle->modules[i]->exit_process) {
++                        cycle->modules[i]->exit_process(cycle);
++                    }
++                }
++
++                ngx_master_process_exit(cycle);
++            }
++        }
++
+         ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "worker cycle");
+ 
+         ngx_process_events_and_timers(cycle);
+ 
+-        if (ngx_terminate || ngx_quit) {
++        if (ngx_terminate) {
++            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "exiting");
+ 
+             for (i = 0; cycle->modules[i]; i++) {
+                 if (cycle->modules[i]->exit_process) {
+@@ -319,6 +337,19 @@ ngx_single_process_cycle(ngx_cycle_t *cy
+             ngx_master_process_exit(cycle);
+         }
+ 
++        if (ngx_quit) {
++            ngx_quit = 0;
++            ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0,
++                          "gracefully shutting down");
++            ngx_setproctitle("process is shutting down");
++
++            if (!ngx_exiting) {
++                ngx_exiting = 1;
++                ngx_close_listening_sockets(cycle);
++                ngx_close_idle_connections(cycle);
++            }
++        }
++
+         if (ngx_reconfigure) {
+             ngx_reconfigure = 0;
+             ngx_log_error(NGX_LOG_NOTICE, cycle->log, 0, "reconfiguring");

util/mirror-tarballs

@@ -62,6 +62,13 @@ if [ "$answer" = "Y" ]; then
     echo
 fi
 
+answer=`$root/util/ver-ge "$main_ver" 1.11.2`
+if [ "$answer" = "Y" ]; then
+    echo "$info_txt applying the single-process-graceful-exit patch"
+    patch -p1 < $root/patches/nginx-$main_ver-single_process_graceful_exit.patch || exit 1
+    echo
+fi
+
 answer=`$root/util/ver-ge "$main_ver" 1.11.2`
 if [ "$answer" = "Y" ]; then
     echo "$info_txt applying the intercept-error-log patch"