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author | Maxim Dounin <mdounin@mdounin.ru> | 2021-12-30 01:08:46 +0300 |
---|---|---|
committer | Maxim Dounin <mdounin@mdounin.ru> | 2021-12-30 01:08:46 +0300 |
commit | 96c342e56035a9676180d03b4659d5b05b9c6b07 (patch) | |
tree | b723bd96fa33a0aeb570cbbfd6121d0b94289193 | |
parent | 614726621797f1267c41f8a8e488eeefff8bdf7f (diff) | |
download | nginx-96c342e56035a9676180d03b4659d5b05b9c6b07.tar.gz |
Events: fixed balancing between workers with EPOLLEXCLUSIVE.
Linux with EPOLLEXCLUSIVE usually notifies only the process which was first
to add the listening socket to the epoll instance. As a result most of the
connections are handled by the first worker process (ticket #2285). To fix
this, we re-add the socket periodically, so other workers will get a chance
to accept connections.
-rw-r--r-- | src/event/ngx_event.c | 5 | ||||
-rw-r--r-- | src/event/ngx_event.h | 1 | ||||
-rw-r--r-- | src/event/ngx_event_accept.c | 58 |
3 files changed, 64 insertions, 0 deletions
diff --git a/src/event/ngx_event.c b/src/event/ngx_event.c index 0d187ca33..47229b507 100644 --- a/src/event/ngx_event.c +++ b/src/event/ngx_event.c @@ -55,6 +55,7 @@ ngx_uint_t ngx_accept_events; ngx_uint_t ngx_accept_mutex_held; ngx_msec_t ngx_accept_mutex_delay; ngx_int_t ngx_accept_disabled; +ngx_uint_t ngx_use_exclusive_accept; #if (NGX_STAT_STUB) @@ -644,6 +645,8 @@ ngx_event_process_init(ngx_cycle_t *cycle) #endif + ngx_use_exclusive_accept = 0; + ngx_queue_init(&ngx_posted_accept_events); ngx_queue_init(&ngx_posted_next_events); ngx_queue_init(&ngx_posted_events); @@ -889,6 +892,8 @@ ngx_event_process_init(ngx_cycle_t *cycle) if ((ngx_event_flags & NGX_USE_EPOLL_EVENT) && ccf->worker_processes > 1) { + ngx_use_exclusive_accept = 1; + if (ngx_add_event(rev, NGX_READ_EVENT, NGX_EXCLUSIVE_EVENT) == NGX_ERROR) { diff --git a/src/event/ngx_event.h b/src/event/ngx_event.h index 51b836132..548c906e0 100644 --- a/src/event/ngx_event.h +++ b/src/event/ngx_event.h @@ -462,6 +462,7 @@ extern ngx_uint_t ngx_accept_events; extern ngx_uint_t ngx_accept_mutex_held; extern ngx_msec_t ngx_accept_mutex_delay; extern ngx_int_t ngx_accept_disabled; +extern ngx_uint_t ngx_use_exclusive_accept; #if (NGX_STAT_STUB) diff --git a/src/event/ngx_event_accept.c b/src/event/ngx_event_accept.c index b05666c76..27038799d 100644 --- a/src/event/ngx_event_accept.c +++ b/src/event/ngx_event_accept.c @@ -11,6 +11,9 @@ static ngx_int_t ngx_disable_accept_events(ngx_cycle_t *cycle, ngx_uint_t all); +#if (NGX_HAVE_EPOLLEXCLUSIVE) +static void ngx_reorder_accept_events(ngx_listening_t *ls); +#endif static void ngx_close_accepted_connection(ngx_connection_t *c); @@ -314,6 +317,10 @@ ngx_event_accept(ngx_event_t *ev) } } while (ev->available); + +#if (NGX_HAVE_EPOLLEXCLUSIVE) + ngx_reorder_accept_events(ls); +#endif } @@ -420,6 +427,57 @@ ngx_disable_accept_events(ngx_cycle_t *cycle, ngx_uint_t all) } +#if (NGX_HAVE_EPOLLEXCLUSIVE) + +static void +ngx_reorder_accept_events(ngx_listening_t *ls) +{ + ngx_connection_t *c; + + /* + * Linux with EPOLLEXCLUSIVE usually notifies only the process which + * was first to add the listening socket to the epoll instance. As + * a result most of the connections are handled by the first worker + * process. To fix this, we re-add the socket periodically, so other + * workers will get a chance to accept connections. + */ + + if (!ngx_use_exclusive_accept) { + return; + } + +#if (NGX_HAVE_REUSEPORT) + + if (ls->reuseport) { + return; + } + +#endif + + c = ls->connection; + + if (c->requests++ % 16 != 0 + && ngx_accept_disabled <= 0) + { + return; + } + + if (ngx_del_event(c->read, NGX_READ_EVENT, NGX_DISABLE_EVENT) + == NGX_ERROR) + { + return; + } + + if (ngx_add_event(c->read, NGX_READ_EVENT, NGX_EXCLUSIVE_EVENT) + == NGX_ERROR) + { + return; + } +} + +#endif + + static void ngx_close_accepted_connection(ngx_connection_t *c) { |