From 76cc69901763bf4bddc6200bcd5c7141de74a577 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Wed, 1 Jul 2020 18:49:24 +0200 Subject: [PATCH] MINOR: config: add a new tune.idle-pool.shared global setting. Enables ('on') or disables ('off') sharing of idle connection pools between threads for a same server. The default is to share them between threads in order to minimize the number of persistent connections to a server, and to optimize the connection reuse rate. But to help with debugging or when suspecting a bug in HAProxy around connection reuse, it can be convenient to forcefully disable this idle pool sharing between multiple threads, and force this option to "off". The default is on. This could have been nice to have during the idle connections debugging, but it's not too late to add it! --- doc/configuration.txt | 10 ++++++++++ include/haproxy/global-t.h | 1 + src/backend.c | 4 ++++ src/haproxy.c | 3 +++ src/server.c | 20 ++++++++++++++++++++ 5 files changed, 38 insertions(+) diff --git a/doc/configuration.txt b/doc/configuration.txt index dd166e775..89b985fb8 100644 --- a/doc/configuration.txt +++ b/doc/configuration.txt @@ -682,6 +682,7 @@ The following keywords are supported in the "global" section : - tune.http.cookielen - tune.http.logurilen - tune.http.maxhdr + - tune.idle-pool.shared - tune.idletimer - tune.lua.forced-yield - tune.lua.maxmem @@ -1949,6 +1950,15 @@ tune.http.maxhdr 1..32767. Keep in mind that each new header consumes 32bits of memory for each session, so don't push this limit too high. +tune.idle-pool.shared { on | off } + Enables ('on') or disables ('off') sharing of idle connection pools between + threads for a same server. The default is to share them between threads in + order to minimize the number of persistent connections to a server, and to + optimize the connection reuse rate. But to help with debugging or when + suspecting a bug in HAProxy around connection reuse, it can be convenient to + forcefully disable this idle pool sharing between multiple threads, and force + this option to "off". The default is on. + tune.idletimer Sets the duration after which haproxy will consider that an empty buffer is probably associated with an idle stream. This is used to optimally adjust diff --git a/include/haproxy/global-t.h b/include/haproxy/global-t.h index 0da246dde..677d98f51 100644 --- a/include/haproxy/global-t.h +++ b/include/haproxy/global-t.h @@ -68,6 +68,7 @@ #define GTUNE_INSECURE_SETUID (1<<17) #define GTUNE_FD_ET (1<<18) #define GTUNE_SCHED_LOW_LATENCY (1<<19) +#define GTUNE_IDLE_POOL_SHARED (1<<20) /* SSL server verify mode */ enum { diff --git a/src/backend.c b/src/backend.c index 0b4cb4c93..f87940be8 100644 --- a/src/backend.c +++ b/src/backend.c @@ -1107,6 +1107,10 @@ static struct connection *conn_backend_get(struct server *srv, int is_safe) if (conn) goto done; + /* pool sharing globally disabled ? */ + if (!(global.tune.options & GTUNE_IDLE_POOL_SHARED)) + goto done; + /* Are we allowed to pick from another thread ? We'll still try * it if we're running low on FDs as we don't want to create * extra conns in this case, otherwise we can give up if we have diff --git a/src/haproxy.c b/src/haproxy.c index c8c869a6f..e733d454d 100644 --- a/src/haproxy.c +++ b/src/haproxy.c @@ -1788,6 +1788,9 @@ static void init(int argc, char **argv) #if defined(SO_REUSEPORT) global.tune.options |= GTUNE_USE_REUSEPORT; #endif +#ifdef USE_THREAD + global.tune.options |= GTUNE_IDLE_POOL_SHARED; +#endif pid = getpid(); progname = *argv; diff --git a/src/server.c b/src/server.c index ac32e1c25..a016b7bd9 100644 --- a/src/server.c +++ b/src/server.c @@ -5333,6 +5333,25 @@ remove: return task; } +/* config parser for global "tune.idle-pool.shared", accepts "on" or "off" */ +static int cfg_parse_idle_pool_shared(char **args, int section_type, struct proxy *curpx, + struct proxy *defpx, const char *file, int line, + char **err) +{ + if (too_many_args(1, args, err, NULL)) + return -1; + + if (strcmp(args[1], "on") == 0) + global.tune.options |= GTUNE_IDLE_POOL_SHARED; + else if (strcmp(args[1], "off") == 0) + global.tune.options &= ~GTUNE_IDLE_POOL_SHARED; + else { + memprintf(err, "'%s' expects either 'on' or 'off' but got '%s'.", args[0], args[1]); + return -1; + } + return 0; +} + /* config parser for global "tune.pool-{low,high}-fd-ratio" */ static int cfg_parse_pool_fd_ratio(char **args, int section_type, struct proxy *curpx, struct proxy *defpx, const char *file, int line, @@ -5360,6 +5379,7 @@ static int cfg_parse_pool_fd_ratio(char **args, int section_type, struct proxy * /* config keyword parsers */ static struct cfg_kw_list cfg_kws = {ILH, { + { CFG_GLOBAL, "tune.idle-pool.shared", cfg_parse_idle_pool_shared }, { CFG_GLOBAL, "tune.pool-high-fd-ratio", cfg_parse_pool_fd_ratio }, { CFG_GLOBAL, "tune.pool-low-fd-ratio", cfg_parse_pool_fd_ratio }, { 0, NULL, NULL }