From 348bc94086d94f27dbda5904174cd379bce7f931 Mon Sep 17 00:00:00 2001 From: Maxim Dounin Date: Mon, 10 Aug 2020 18:53:07 +0300 Subject: [PATCH] Core: reusing connections in advance. Reworked connections reuse, so closing connections is attempted in advance, as long as number of free connections is less than 1/16 of worker connections configured. This ensures that new connections can be handled even if closing a reusable connection requires some time, for example, for a lingering close (ticket #2017). The 1/16 ratio is selected to be smaller than 1/8 used for disabling accept when working with accept mutex, so nginx will try to balance new connections to different workers first, and will start reusing connections only if this won't help. --- src/core/ngx_connection.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/src/core/ngx_connection.c b/src/core/ngx_connection.c index 91e1b3b2e..c082d0dac 100644 --- a/src/core/ngx_connection.c +++ b/src/core/ngx_connection.c @@ -1107,12 +1107,9 @@ ngx_get_connection(ngx_socket_t s, ngx_log_t *log) return NULL; } - c = ngx_cycle->free_connections; + ngx_drain_connections((ngx_cycle_t *) ngx_cycle); - if (c == NULL) { - ngx_drain_connections((ngx_cycle_t *) ngx_cycle); - c = ngx_cycle->free_connections; - } + c = ngx_cycle->free_connections; if (c == NULL) { ngx_log_error(NGX_LOG_ALERT, log, 0, @@ -1298,7 +1295,9 @@ ngx_drain_connections(ngx_cycle_t *cycle) ngx_queue_t *q; ngx_connection_t *c; - if (cycle->reusable_connections_n == 0) { + if (cycle->free_connection_n > cycle->connection_n / 16 + || cycle->reusable_connections_n == 0) + { return; }