From 76489fb7e0ab9142651b91ee8072c6cda270dd09 Mon Sep 17 00:00:00 2001 From: Andrew Clayton Date: Wed, 14 Aug 2024 00:33:13 +0100 Subject: conf, router: Make the listen(2) backlog configurable @oopsoop2 on GitHub reported a performance issue related to the default listen(2) backlog size of 511 on nginx. They found that increasing it helped, nginx has a config option to configure this. They would like to be able to do the same on Unit (which also defaults to 511 on some systems). This seems reasonable. NOTE: On Linux before commit 97c15fa38 ("socket: Use a default listen backlog of -1 on Linux") we defaulted to 511. Since that commit we default to the Kernels default, which before 5.4 is 128 and after is 4096. This adds a new per-listener 'backlog' config option, e.g { "listeners": { "[::1]:8080": { "pass": "routes", "backlog": 1024 }, } ... } This doesn't effect the control socket. Closes: https://github.com/nginx/unit/issues/1384 Reported-by: Signed-off-by: Andrew Clayton --- src/nxt_conf_validation.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'src/nxt_conf_validation.c') diff --git a/src/nxt_conf_validation.c b/src/nxt_conf_validation.c index c9c51ac1..8f31bd18 100644 --- a/src/nxt_conf_validation.c +++ b/src/nxt_conf_validation.c @@ -178,6 +178,8 @@ static nxt_int_t nxt_conf_vldt_app_name(nxt_conf_validation_t *vldt, nxt_conf_value_t *value, void *data); static nxt_int_t nxt_conf_vldt_forwarded(nxt_conf_validation_t *vldt, nxt_conf_value_t *value, void *data); +static nxt_int_t nxt_conf_vldt_listen_backlog(nxt_conf_validation_t *vldt, + nxt_conf_value_t *value, void *data); static nxt_int_t nxt_conf_vldt_app(nxt_conf_validation_t *vldt, nxt_str_t *name, nxt_conf_value_t *value); static nxt_int_t nxt_conf_vldt_object(nxt_conf_validation_t *vldt, @@ -430,6 +432,10 @@ static nxt_conf_vldt_object_t nxt_conf_vldt_listener_members[] = { .type = NXT_CONF_VLDT_OBJECT, .validator = nxt_conf_vldt_object, .u.members = nxt_conf_vldt_client_ip_members + }, { + .name = nxt_string("backlog"), + .type = NXT_CONF_VLDT_NUMBER, + .validator = nxt_conf_vldt_listen_backlog, }, #if (NXT_TLS) @@ -2704,6 +2710,32 @@ nxt_conf_vldt_forwarded(nxt_conf_validation_t *vldt, nxt_conf_value_t *value, } +static nxt_int_t +nxt_conf_vldt_listen_backlog(nxt_conf_validation_t *vldt, + nxt_conf_value_t *value, void *data) +{ + int64_t backlog; + + backlog = nxt_conf_get_number(value); + + /* + * POSIX allows this to be 0 and some systems use -1 to + * indicate to use the OS's default value. + */ + if (backlog < -1) { + return nxt_conf_vldt_error(vldt, "The \"backlog\" number must be " + "equal to or greater than -1."); + } + + if (backlog > NXT_INT32_T_MAX) { + return nxt_conf_vldt_error(vldt, "The \"backlog\" number must " + "not exceed %d.", NXT_INT32_T_MAX); + } + + return NXT_OK; +} + + static nxt_int_t nxt_conf_vldt_app(nxt_conf_validation_t *vldt, nxt_str_t *name, nxt_conf_value_t *value) -- cgit