Core: idle connections now closed only once on exiting.
Iterating through all connections takes a lot of CPU time, especially
with large number of worker connections configured. As a result
nginx processes used to consume CPU time during graceful shutdown.
To mitigate this we now only do a full scan for idle connections when
shutdown signal is received.
Transitions of connections to idle ones are now expected to be
avoided if the ngx_exiting flag is set. The upstream keepalive module
was modified to follow this.
diff --git a/src/core/ngx_connection.c b/src/core/ngx_connection.c
index 00c5a08..9f2675b 100644
--- a/src/core/ngx_connection.c
+++ b/src/core/ngx_connection.c
@@ -1163,6 +1163,26 @@
}
+void
+ngx_close_idle_connections(ngx_cycle_t *cycle)
+{
+ ngx_uint_t i;
+ ngx_connection_t *c;
+
+ c = cycle->connections;
+
+ for (i = 0; i < cycle->connection_n; i++) {
+
+ /* THREAD: lock */
+
+ if (c[i].fd != -1 && c[i].idle) {
+ c[i].close = 1;
+ c[i].read->handler(c[i].read);
+ }
+ }
+}
+
+
ngx_int_t
ngx_connection_local_sockaddr(ngx_connection_t *c, ngx_str_t *s,
ngx_uint_t port)
diff --git a/src/core/ngx_connection.h b/src/core/ngx_connection.h
index a49aa95..c3aca7f 100644
--- a/src/core/ngx_connection.h
+++ b/src/core/ngx_connection.h
@@ -215,6 +215,7 @@
void ngx_configure_listening_sockets(ngx_cycle_t *cycle);
void ngx_close_listening_sockets(ngx_cycle_t *cycle);
void ngx_close_connection(ngx_connection_t *c);
+void ngx_close_idle_connections(ngx_cycle_t *cycle);
ngx_int_t ngx_connection_local_sockaddr(ngx_connection_t *c, ngx_str_t *s,
ngx_uint_t port);
ngx_int_t ngx_connection_error(ngx_connection_t *c, ngx_err_t err, char *text);
diff --git a/src/http/modules/ngx_http_upstream_keepalive_module.c b/src/http/modules/ngx_http_upstream_keepalive_module.c
index 768881e..51887b4 100644
--- a/src/http/modules/ngx_http_upstream_keepalive_module.c
+++ b/src/http/modules/ngx_http_upstream_keepalive_module.c
@@ -302,6 +302,10 @@
goto invalid;
}
+ if (ngx_terminate || ngx_exiting) {
+ goto invalid;
+ }
+
if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
goto invalid;
}
diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index c69932e..5da0911 100644
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -728,9 +728,6 @@
{
ngx_int_t worker = (intptr_t) data;
- ngx_uint_t i;
- ngx_connection_t *c;
-
ngx_process = NGX_PROCESS_WORKER;
ngx_worker = worker;
@@ -741,19 +738,6 @@
for ( ;; ) {
if (ngx_exiting) {
-
- c = cycle->connections;
-
- for (i = 0; i < cycle->connection_n; i++) {
-
- /* THREAD: lock */
-
- if (c[i].fd != -1 && c[i].idle) {
- c[i].close = 1;
- c[i].read->handler(c[i].read);
- }
- }
-
ngx_event_cancel_timers();
if (ngx_event_timer_rbtree.root == ngx_event_timer_rbtree.sentinel)
@@ -781,8 +765,9 @@
ngx_setproctitle("worker process is shutting down");
if (!ngx_exiting) {
- ngx_close_listening_sockets(cycle);
ngx_exiting = 1;
+ ngx_close_listening_sockets(cycle);
+ ngx_close_idle_connections(cycle);
}
}
diff --git a/src/os/win32/ngx_process_cycle.c b/src/os/win32/ngx_process_cycle.c
index 203bece..06ff8b5 100644
--- a/src/os/win32/ngx_process_cycle.c
+++ b/src/os/win32/ngx_process_cycle.c
@@ -761,10 +761,8 @@
static ngx_thread_value_t __stdcall
ngx_worker_thread(void *data)
{
- ngx_int_t n;
- ngx_uint_t i;
- ngx_cycle_t *cycle;
- ngx_connection_t *c;
+ ngx_int_t n;
+ ngx_cycle_t *cycle;
cycle = (ngx_cycle_t *) ngx_cycle;
@@ -780,19 +778,6 @@
while (!ngx_quit) {
if (ngx_exiting) {
-
- c = cycle->connections;
-
- for (i = 0; i < cycle->connection_n; i++) {
-
- /* THREAD: lock */
-
- if (c[i].fd != (ngx_socket_t) -1 && c[i].idle) {
- c[i].close = 1;
- c[i].read->handler(c[i].read);
- }
- }
-
ngx_event_cancel_timers();
if (ngx_event_timer_rbtree.root
@@ -814,8 +799,9 @@
ngx_quit = 0;
if (!ngx_exiting) {
- ngx_close_listening_sockets(cycle);
ngx_exiting = 1;
+ ngx_close_listening_sockets(cycle);
+ ngx_close_idle_connections(cycle);
}
}
