Mercurial > hg > nginx
view src/http/ngx_http_upstream_round_robin.c @ 7698:5440ff4ac6fc
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.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 10 Aug 2020 18:53:07 +0300 |
parents | b99cbafd51da |
children | 90cc7194e993 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #define ngx_http_upstream_tries(p) ((p)->number \ + ((p)->next ? (p)->next->number : 0)) static ngx_http_upstream_rr_peer_t *ngx_http_upstream_get_peer( ngx_http_upstream_rr_peer_data_t *rrp); #if (NGX_HTTP_SSL) static ngx_int_t ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data); static void ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data); #endif ngx_int_t ngx_http_upstream_init_round_robin(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us) { ngx_url_t u; ngx_uint_t i, j, n, w; ngx_http_upstream_server_t *server; ngx_http_upstream_rr_peer_t *peer, **peerp; ngx_http_upstream_rr_peers_t *peers, *backup; us->peer.init = ngx_http_upstream_init_round_robin_peer; if (us->servers) { server = us->servers->elts; n = 0; w = 0; for (i = 0; i < us->servers->nelts; i++) { if (server[i].backup) { continue; } n += server[i].naddrs; w += server[i].naddrs * server[i].weight; } if (n == 0) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no servers in upstream \"%V\" in %s:%ui", &us->host, us->file_name, us->line); return NGX_ERROR; } peers = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peer_t) * n); if (peer == NULL) { return NGX_ERROR; } peers->single = (n == 1); peers->number = n; peers->weighted = (w != n); peers->total_weight = w; peers->name = &us->host; n = 0; peerp = &peers->peer; for (i = 0; i < us->servers->nelts; i++) { if (server[i].backup) { continue; } for (j = 0; j < server[i].naddrs; j++) { peer[n].sockaddr = server[i].addrs[j].sockaddr; peer[n].socklen = server[i].addrs[j].socklen; peer[n].name = server[i].addrs[j].name; peer[n].weight = server[i].weight; peer[n].effective_weight = server[i].weight; peer[n].current_weight = 0; peer[n].max_conns = server[i].max_conns; peer[n].max_fails = server[i].max_fails; peer[n].fail_timeout = server[i].fail_timeout; peer[n].down = server[i].down; peer[n].server = server[i].name; *peerp = &peer[n]; peerp = &peer[n].next; n++; } } us->peer.data = peers; /* backup servers */ n = 0; w = 0; for (i = 0; i < us->servers->nelts; i++) { if (!server[i].backup) { continue; } n += server[i].naddrs; w += server[i].naddrs * server[i].weight; } if (n == 0) { return NGX_OK; } backup = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t)); if (backup == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peer_t) * n); if (peer == NULL) { return NGX_ERROR; } peers->single = 0; backup->single = 0; backup->number = n; backup->weighted = (w != n); backup->total_weight = w; backup->name = &us->host; n = 0; peerp = &backup->peer; for (i = 0; i < us->servers->nelts; i++) { if (!server[i].backup) { continue; } for (j = 0; j < server[i].naddrs; j++) { peer[n].sockaddr = server[i].addrs[j].sockaddr; peer[n].socklen = server[i].addrs[j].socklen; peer[n].name = server[i].addrs[j].name; peer[n].weight = server[i].weight; peer[n].effective_weight = server[i].weight; peer[n].current_weight = 0; peer[n].max_conns = server[i].max_conns; peer[n].max_fails = server[i].max_fails; peer[n].fail_timeout = server[i].fail_timeout; peer[n].down = server[i].down; peer[n].server = server[i].name; *peerp = &peer[n]; peerp = &peer[n].next; n++; } } peers->next = backup; return NGX_OK; } /* an upstream implicitly defined by proxy_pass, etc. */ if (us->port == 0) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no port in upstream \"%V\" in %s:%ui", &us->host, us->file_name, us->line); return NGX_ERROR; } ngx_memzero(&u, sizeof(ngx_url_t)); u.host = us->host; u.port = us->port; if (ngx_inet_resolve_host(cf->pool, &u) != NGX_OK) { if (u.err) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "%s in upstream \"%V\" in %s:%ui", u.err, &us->host, us->file_name, us->line); } return NGX_ERROR; } n = u.naddrs; peers = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peer_t) * n); if (peer == NULL) { return NGX_ERROR; } peers->single = (n == 1); peers->number = n; peers->weighted = 0; peers->total_weight = n; peers->name = &us->host; peerp = &peers->peer; for (i = 0; i < u.naddrs; i++) { peer[i].sockaddr = u.addrs[i].sockaddr; peer[i].socklen = u.addrs[i].socklen; peer[i].name = u.addrs[i].name; peer[i].weight = 1; peer[i].effective_weight = 1; peer[i].current_weight = 0; peer[i].max_conns = 0; peer[i].max_fails = 1; peer[i].fail_timeout = 10; *peerp = &peer[i]; peerp = &peer[i].next; } us->peer.data = peers; /* implicitly defined upstream has no backup servers */ return NGX_OK; } ngx_int_t ngx_http_upstream_init_round_robin_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us) { ngx_uint_t n; ngx_http_upstream_rr_peer_data_t *rrp; rrp = r->upstream->peer.data; if (rrp == NULL) { rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t)); if (rrp == NULL) { return NGX_ERROR; } r->upstream->peer.data = rrp; } rrp->peers = us->peer.data; rrp->current = NULL; rrp->config = 0; n = rrp->peers->number; if (rrp->peers->next && rrp->peers->next->number > n) { n = rrp->peers->next->number; } if (n <= 8 * sizeof(uintptr_t)) { rrp->tried = &rrp->data; rrp->data = 0; } else { n = (n + (8 * sizeof(uintptr_t) - 1)) / (8 * sizeof(uintptr_t)); rrp->tried = ngx_pcalloc(r->pool, n * sizeof(uintptr_t)); if (rrp->tried == NULL) { return NGX_ERROR; } } r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer; r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer; r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers); #if (NGX_HTTP_SSL) r->upstream->peer.set_session = ngx_http_upstream_set_round_robin_peer_session; r->upstream->peer.save_session = ngx_http_upstream_save_round_robin_peer_session; #endif return NGX_OK; } ngx_int_t ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r, ngx_http_upstream_resolved_t *ur) { u_char *p; size_t len; socklen_t socklen; ngx_uint_t i, n; struct sockaddr *sockaddr; ngx_http_upstream_rr_peer_t *peer, **peerp; ngx_http_upstream_rr_peers_t *peers; ngx_http_upstream_rr_peer_data_t *rrp; rrp = r->upstream->peer.data; if (rrp == NULL) { rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t)); if (rrp == NULL) { return NGX_ERROR; } r->upstream->peer.data = rrp; } peers = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peer_t) * ur->naddrs); if (peer == NULL) { return NGX_ERROR; } peers->single = (ur->naddrs == 1); peers->number = ur->naddrs; peers->name = &ur->host; if (ur->sockaddr) { peer[0].sockaddr = ur->sockaddr; peer[0].socklen = ur->socklen; peer[0].name = ur->name.data ? ur->name : ur->host; peer[0].weight = 1; peer[0].effective_weight = 1; peer[0].current_weight = 0; peer[0].max_conns = 0; peer[0].max_fails = 1; peer[0].fail_timeout = 10; peers->peer = peer; } else { peerp = &peers->peer; for (i = 0; i < ur->naddrs; i++) { socklen = ur->addrs[i].socklen; sockaddr = ngx_palloc(r->pool, socklen); if (sockaddr == NULL) { return NGX_ERROR; } ngx_memcpy(sockaddr, ur->addrs[i].sockaddr, socklen); ngx_inet_set_port(sockaddr, ur->port); p = ngx_pnalloc(r->pool, NGX_SOCKADDR_STRLEN); if (p == NULL) { return NGX_ERROR; } len = ngx_sock_ntop(sockaddr, socklen, p, NGX_SOCKADDR_STRLEN, 1); peer[i].sockaddr = sockaddr; peer[i].socklen = socklen; peer[i].name.len = len; peer[i].name.data = p; peer[i].weight = 1; peer[i].effective_weight = 1; peer[i].current_weight = 0; peer[i].max_conns = 0; peer[i].max_fails = 1; peer[i].fail_timeout = 10; *peerp = &peer[i]; peerp = &peer[i].next; } } rrp->peers = peers; rrp->current = NULL; rrp->config = 0; if (rrp->peers->number <= 8 * sizeof(uintptr_t)) { rrp->tried = &rrp->data; rrp->data = 0; } else { n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1)) / (8 * sizeof(uintptr_t)); rrp->tried = ngx_pcalloc(r->pool, n * sizeof(uintptr_t)); if (rrp->tried == NULL) { return NGX_ERROR; } } r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer; r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer; r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers); #if (NGX_HTTP_SSL) r->upstream->peer.set_session = ngx_http_upstream_empty_set_session; r->upstream->peer.save_session = ngx_http_upstream_empty_save_session; #endif return NGX_OK; } ngx_int_t ngx_http_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_rr_peer_data_t *rrp = data; ngx_int_t rc; ngx_uint_t i, n; ngx_http_upstream_rr_peer_t *peer; ngx_http_upstream_rr_peers_t *peers; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get rr peer, try: %ui", pc->tries); pc->cached = 0; pc->connection = NULL; peers = rrp->peers; ngx_http_upstream_rr_peers_wlock(peers); if (peers->single) { peer = peers->peer; if (peer->down) { goto failed; } if (peer->max_conns && peer->conns >= peer->max_conns) { goto failed; } rrp->current = peer; } else { /* there are several peers */ peer = ngx_http_upstream_get_peer(rrp); if (peer == NULL) { goto failed; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get rr peer, current: %p %i", peer, peer->current_weight); } pc->sockaddr = peer->sockaddr; pc->socklen = peer->socklen; pc->name = &peer->name; peer->conns++; ngx_http_upstream_rr_peers_unlock(peers); return NGX_OK; failed: if (peers->next) { ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0, "backup servers"); rrp->peers = peers->next; n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1)) / (8 * sizeof(uintptr_t)); for (i = 0; i < n; i++) { rrp->tried[i] = 0; } ngx_http_upstream_rr_peers_unlock(peers); rc = ngx_http_upstream_get_round_robin_peer(pc, rrp); if (rc != NGX_BUSY) { return rc; } ngx_http_upstream_rr_peers_wlock(peers); } ngx_http_upstream_rr_peers_unlock(peers); pc->name = peers->name; return NGX_BUSY; } static ngx_http_upstream_rr_peer_t * ngx_http_upstream_get_peer(ngx_http_upstream_rr_peer_data_t *rrp) { time_t now; uintptr_t m; ngx_int_t total; ngx_uint_t i, n, p; ngx_http_upstream_rr_peer_t *peer, *best; now = ngx_time(); best = NULL; total = 0; #if (NGX_SUPPRESS_WARN) p = 0; #endif for (peer = rrp->peers->peer, i = 0; peer; peer = peer->next, i++) { n = i / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t)); if (rrp->tried[n] & m) { continue; } if (peer->down) { continue; } if (peer->max_fails && peer->fails >= peer->max_fails && now - peer->checked <= peer->fail_timeout) { continue; } if (peer->max_conns && peer->conns >= peer->max_conns) { continue; } peer->current_weight += peer->effective_weight; total += peer->effective_weight; if (peer->effective_weight < peer->weight) { peer->effective_weight++; } if (best == NULL || peer->current_weight > best->current_weight) { best = peer; p = i; } } if (best == NULL) { return NULL; } rrp->current = best; n = p / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t)); rrp->tried[n] |= m; best->current_weight -= total; if (now - best->checked > best->fail_timeout) { best->checked = now; } return best; } void ngx_http_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data, ngx_uint_t state) { ngx_http_upstream_rr_peer_data_t *rrp = data; time_t now; ngx_http_upstream_rr_peer_t *peer; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "free rr peer %ui %ui", pc->tries, state); /* TODO: NGX_PEER_KEEPALIVE */ peer = rrp->current; ngx_http_upstream_rr_peers_rlock(rrp->peers); ngx_http_upstream_rr_peer_lock(rrp->peers, peer); if (rrp->peers->single) { peer->conns--; ngx_http_upstream_rr_peer_unlock(rrp->peers, peer); ngx_http_upstream_rr_peers_unlock(rrp->peers); pc->tries = 0; return; } if (state & NGX_PEER_FAILED) { now = ngx_time(); peer->fails++; peer->accessed = now; peer->checked = now; if (peer->max_fails) { peer->effective_weight -= peer->weight / peer->max_fails; if (peer->fails >= peer->max_fails) { ngx_log_error(NGX_LOG_WARN, pc->log, 0, "upstream server temporarily disabled"); } } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "free rr peer failed: %p %i", peer, peer->effective_weight); if (peer->effective_weight < 0) { peer->effective_weight = 0; } } else { /* mark peer live if check passed */ if (peer->accessed < peer->checked) { peer->fails = 0; } } peer->conns--; ngx_http_upstream_rr_peer_unlock(rrp->peers, peer); ngx_http_upstream_rr_peers_unlock(rrp->peers); if (pc->tries) { pc->tries--; } } #if (NGX_HTTP_SSL) ngx_int_t ngx_http_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_rr_peer_data_t *rrp = data; ngx_int_t rc; ngx_ssl_session_t *ssl_session; ngx_http_upstream_rr_peer_t *peer; #if (NGX_HTTP_UPSTREAM_ZONE) int len; const u_char *p; ngx_http_upstream_rr_peers_t *peers; u_char buf[NGX_SSL_MAX_SESSION_SIZE]; #endif peer = rrp->current; #if (NGX_HTTP_UPSTREAM_ZONE) peers = rrp->peers; if (peers->shpool) { ngx_http_upstream_rr_peers_rlock(peers); ngx_http_upstream_rr_peer_lock(peers, peer); if (peer->ssl_session == NULL) { ngx_http_upstream_rr_peer_unlock(peers, peer); ngx_http_upstream_rr_peers_unlock(peers); return NGX_OK; } len = peer->ssl_session_len; ngx_memcpy(buf, peer->ssl_session, len); ngx_http_upstream_rr_peer_unlock(peers, peer); ngx_http_upstream_rr_peers_unlock(peers); p = buf; ssl_session = d2i_SSL_SESSION(NULL, &p, len); rc = ngx_ssl_set_session(pc->connection, ssl_session); ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "set session: %p", ssl_session); ngx_ssl_free_session(ssl_session); return rc; } #endif ssl_session = peer->ssl_session; rc = ngx_ssl_set_session(pc->connection, ssl_session); ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "set session: %p", ssl_session); return rc; } void ngx_http_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_rr_peer_data_t *rrp = data; ngx_ssl_session_t *old_ssl_session, *ssl_session; ngx_http_upstream_rr_peer_t *peer; #if (NGX_HTTP_UPSTREAM_ZONE) int len; u_char *p; ngx_http_upstream_rr_peers_t *peers; u_char buf[NGX_SSL_MAX_SESSION_SIZE]; #endif #if (NGX_HTTP_UPSTREAM_ZONE) peers = rrp->peers; if (peers->shpool) { ssl_session = ngx_ssl_get0_session(pc->connection); if (ssl_session == NULL) { return; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "save session: %p", ssl_session); len = i2d_SSL_SESSION(ssl_session, NULL); /* do not cache too big session */ if (len > NGX_SSL_MAX_SESSION_SIZE) { return; } p = buf; (void) i2d_SSL_SESSION(ssl_session, &p); peer = rrp->current; ngx_http_upstream_rr_peers_rlock(peers); ngx_http_upstream_rr_peer_lock(peers, peer); if (len > peer->ssl_session_len) { ngx_shmtx_lock(&peers->shpool->mutex); if (peer->ssl_session) { ngx_slab_free_locked(peers->shpool, peer->ssl_session); } peer->ssl_session = ngx_slab_alloc_locked(peers->shpool, len); ngx_shmtx_unlock(&peers->shpool->mutex); if (peer->ssl_session == NULL) { peer->ssl_session_len = 0; ngx_http_upstream_rr_peer_unlock(peers, peer); ngx_http_upstream_rr_peers_unlock(peers); return; } peer->ssl_session_len = len; } ngx_memcpy(peer->ssl_session, buf, len); ngx_http_upstream_rr_peer_unlock(peers, peer); ngx_http_upstream_rr_peers_unlock(peers); return; } #endif ssl_session = ngx_ssl_get_session(pc->connection); if (ssl_session == NULL) { return; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "save session: %p", ssl_session); peer = rrp->current; old_ssl_session = peer->ssl_session; peer->ssl_session = ssl_session; if (old_ssl_session) { ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "old session: %p", old_ssl_session); /* TODO: may block */ ngx_ssl_free_session(old_ssl_session); } } static ngx_int_t ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data) { return NGX_OK; } static void ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data) { return; } #endif