[nginx] Core: idle connections now closed only once on exiting.
Valentin Bartenev
vbart at nginx.com
Tue Aug 11 13:29:04 UTC 2015
details: http://hg.nginx.org/nginx/rev/5e6142609e48
branches:
changeset: 6220:5e6142609e48
user: Valentin Bartenev <vbart at nginx.com>
date: Tue Aug 11 16:28:55 2015 +0300
description:
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.
diffstat:
src/core/ngx_connection.c | 20 +++++++++++++++++
src/core/ngx_connection.h | 1 +
src/http/modules/ngx_http_upstream_keepalive_module.c | 4 +++
src/os/unix/ngx_process_cycle.c | 19 +--------------
src/os/win32/ngx_process_cycle.c | 22 +++---------------
5 files changed, 31 insertions(+), 35 deletions(-)
diffs (146 lines):
diff -r 808fd1f0b94b -r 5e6142609e48 src/core/ngx_connection.c
--- a/src/core/ngx_connection.c Tue Aug 11 10:28:00 2015 +0300
+++ b/src/core/ngx_connection.c Tue Aug 11 16:28:55 2015 +0300
@@ -1163,6 +1163,26 @@ ngx_drain_connections(void)
}
+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 -r 808fd1f0b94b -r 5e6142609e48 src/core/ngx_connection.h
--- a/src/core/ngx_connection.h Tue Aug 11 10:28:00 2015 +0300
+++ b/src/core/ngx_connection.h Tue Aug 11 16:28:55 2015 +0300
@@ -215,6 +215,7 @@ ngx_int_t ngx_open_listening_sockets(ngx
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 -r 808fd1f0b94b -r 5e6142609e48 src/http/modules/ngx_http_upstream_keepalive_module.c
--- a/src/http/modules/ngx_http_upstream_keepalive_module.c Tue Aug 11 10:28:00 2015 +0300
+++ b/src/http/modules/ngx_http_upstream_keepalive_module.c Tue Aug 11 16:28:55 2015 +0300
@@ -302,6 +302,10 @@ ngx_http_upstream_free_keepalive_peer(ng
goto invalid;
}
+ if (ngx_terminate || ngx_exiting) {
+ goto invalid;
+ }
+
if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
goto invalid;
}
diff -r 808fd1f0b94b -r 5e6142609e48 src/os/unix/ngx_process_cycle.c
--- a/src/os/unix/ngx_process_cycle.c Tue Aug 11 10:28:00 2015 +0300
+++ b/src/os/unix/ngx_process_cycle.c Tue Aug 11 16:28:55 2015 +0300
@@ -728,9 +728,6 @@ ngx_worker_process_cycle(ngx_cycle_t *cy
{
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 @@ ngx_worker_process_cycle(ngx_cycle_t *cy
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_worker_process_cycle(ngx_cycle_t *cy
ngx_setproctitle("worker process is shutting down");
if (!ngx_exiting) {
+ ngx_exiting = 1;
ngx_close_listening_sockets(cycle);
- ngx_exiting = 1;
+ ngx_close_idle_connections(cycle);
}
}
diff -r 808fd1f0b94b -r 5e6142609e48 src/os/win32/ngx_process_cycle.c
--- a/src/os/win32/ngx_process_cycle.c Tue Aug 11 10:28:00 2015 +0300
+++ b/src/os/win32/ngx_process_cycle.c Tue Aug 11 16:28:55 2015 +0300
@@ -761,10 +761,8 @@ failed:
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 @@ ngx_worker_thread(void *data)
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_worker_thread(void *data)
ngx_quit = 0;
if (!ngx_exiting) {
+ ngx_exiting = 1;
ngx_close_listening_sockets(cycle);
- ngx_exiting = 1;
+ ngx_close_idle_connections(cycle);
}
}
More information about the nginx-devel
mailing list