Mercurial > hg > nginx-quic
view src/http/ngx_http_upstream_round_robin.c @ 3440:88741ec7731a stable-0.7
merge r3294, r3305:
Fix a bug introduced in r2032: After a child process has read a terminate
message from a channel, the process tries to read the channel again.
The kernel (at least FreeBSD) may preempt the process and sends a SIGIO
signal to a master process. The master process sends a new terminate message,
the kernel switches again to the the child process, and the child process
reads the messages instead of an EAGAIN error. And this may repeat over
and over. Being that the child process can not exit the cycle and test
the termination flag set by the message handler.
The fix disallow the master process to send a new terminate message on
SIGIO signal reception. It may send the message only on SIGALARM signal.
author | Igor Sysoev <igor@sysoev.ru> |
---|---|
date | Mon, 01 Feb 2010 15:49:36 +0000 |
parents | 7af1e5fe102c |
children | ff127ba3b091 |
line wrap: on
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/* * Copyright (C) Igor Sysoev */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static ngx_int_t ngx_http_upstream_cmp_servers(const void *one, const void *two); static ngx_uint_t ngx_http_upstream_get_peer(ngx_http_upstream_rr_peers_t *peers); 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; ngx_http_upstream_server_t *server; 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; for (i = 0; i < us->servers->nelts; i++) { if (server[i].backup) { continue; } n += server[i].naddrs; } peers = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t) + sizeof(ngx_http_upstream_rr_peer_t) * (n - 1)); if (peers == NULL) { return NGX_ERROR; } peers->single = (n == 1); peers->number = n; peers->name = &us->host; n = 0; for (i = 0; i < us->servers->nelts; i++) { for (j = 0; j < server[i].naddrs; j++) { if (server[i].backup) { continue; } peers->peer[n].sockaddr = server[i].addrs[j].sockaddr; peers->peer[n].socklen = server[i].addrs[j].socklen; peers->peer[n].name = server[i].addrs[j].name; peers->peer[n].max_fails = server[i].max_fails; peers->peer[n].fail_timeout = server[i].fail_timeout; peers->peer[n].down = server[i].down; peers->peer[n].weight = server[i].down ? 0 : server[i].weight; peers->peer[n].current_weight = peers->peer[n].weight; n++; } } us->peer.data = peers; ngx_sort(&peers->peer[0], (size_t) n, sizeof(ngx_http_upstream_rr_peer_t), ngx_http_upstream_cmp_servers); /* backup servers */ n = 0; for (i = 0; i < us->servers->nelts; i++) { if (!server[i].backup) { continue; } n += server[i].naddrs; } if (n == 0) { return NGX_OK; } backup = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t) + sizeof(ngx_http_upstream_rr_peer_t) * (n - 1)); if (backup == NULL) { return NGX_ERROR; } peers->single = 0; backup->single = 0; backup->number = n; backup->name = &us->host; n = 0; for (i = 0; i < us->servers->nelts; i++) { for (j = 0; j < server[i].naddrs; j++) { if (!server[i].backup) { continue; } backup->peer[n].sockaddr = server[i].addrs[j].sockaddr; backup->peer[n].socklen = server[i].addrs[j].socklen; backup->peer[n].name = server[i].addrs[j].name; backup->peer[n].weight = server[i].weight; backup->peer[n].current_weight = server[i].weight; backup->peer[n].max_fails = server[i].max_fails; backup->peer[n].fail_timeout = server[i].fail_timeout; backup->peer[n].down = server[i].down; n++; } } peers->next = backup; ngx_sort(&backup->peer[0], (size_t) n, sizeof(ngx_http_upstream_rr_peer_t), ngx_http_upstream_cmp_servers); return NGX_OK; } /* an upstream implicitly defined by proxy_pass, etc. */ if (us->port == 0 && us->default_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 = (in_port_t) (us->port ? us->port : us->default_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) + sizeof(ngx_http_upstream_rr_peer_t) * (n - 1)); if (peers == NULL) { return NGX_ERROR; } peers->single = (n == 1); peers->number = n; peers->name = &us->host; for (i = 0; i < u.naddrs; i++) { peers->peer[i].sockaddr = u.addrs[i].sockaddr; peers->peer[i].socklen = u.addrs[i].socklen; peers->peer[i].name = u.addrs[i].name; peers->peer[i].weight = 1; peers->peer[i].current_weight = 1; peers->peer[i].max_fails = 1; peers->peer[i].fail_timeout = 10; } us->peer.data = peers; /* implicitly defined upstream has no backup servers */ return NGX_OK; } static ngx_int_t ngx_http_upstream_cmp_servers(const void *one, const void *two) { ngx_http_upstream_rr_peer_t *first, *second; first = (ngx_http_upstream_rr_peer_t *) one; second = (ngx_http_upstream_rr_peer_t *) two; return (first->weight < second->weight); } 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 = 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 = rrp->peers->number; #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; ngx_uint_t i, n; struct sockaddr_in *sin; 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) + sizeof(ngx_http_upstream_rr_peer_t) * (ur->naddrs - 1)); if (peers == NULL) { return NGX_ERROR; } peers->single = (ur->naddrs == 1); peers->number = ur->naddrs; peers->name = &ur->host; if (ur->sockaddr) { peers->peer[0].sockaddr = ur->sockaddr; peers->peer[0].socklen = ur->socklen; peers->peer[0].name = ur->host; peers->peer[0].weight = 1; peers->peer[0].current_weight = 1; peers->peer[0].max_fails = 1; peers->peer[0].fail_timeout = 10; } else { for (i = 0; i < ur->naddrs; i++) { len = NGX_INET_ADDRSTRLEN + sizeof(":65536") - 1; p = ngx_pnalloc(r->pool, len); if (p == NULL) { return NGX_ERROR; } len = ngx_inet_ntop(AF_INET, &ur->addrs[i], p, NGX_INET_ADDRSTRLEN); len = ngx_sprintf(&p[len], ":%d", ur->port) - p; sin = ngx_pcalloc(r->pool, sizeof(struct sockaddr_in)); if (sin == NULL) { return NGX_ERROR; } sin->sin_family = AF_INET; sin->sin_port = htons(ur->port); sin->sin_addr.s_addr = ur->addrs[i]; peers->peer[i].sockaddr = (struct sockaddr *) sin; peers->peer[i].socklen = sizeof(struct sockaddr_in); peers->peer[i].name.len = len; peers->peer[i].name.data = p; peers->peer[i].weight = 1; peers->peer[i].current_weight = 1; peers->peer[i].max_fails = 1; peers->peer[i].fail_timeout = 10; } } rrp->peers = peers; rrp->current = 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 = rrp->peers->number; #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_get_round_robin_peer(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_rr_peer_data_t *rrp = data; time_t now; uintptr_t m; ngx_int_t rc; ngx_uint_t i, n; ngx_connection_t *c; 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); now = ngx_time(); /* ngx_lock_mutex(rrp->peers->mutex); */ if (rrp->peers->last_cached) { /* cached connection */ c = rrp->peers->cached[rrp->peers->last_cached]; rrp->peers->last_cached--; /* ngx_unlock_mutex(ppr->peers->mutex); */ #if (NGX_THREADS) c->read->lock = c->read->own_lock; c->write->lock = c->write->own_lock; #endif pc->connection = c; pc->cached = 1; return NGX_OK; } pc->cached = 0; pc->connection = NULL; if (rrp->peers->single) { peer = &rrp->peers->peer[0]; } else { /* there are several peers */ if (pc->tries == rrp->peers->number) { /* it's a first try - get a current peer */ i = pc->tries; for ( ;; ) { rrp->current = ngx_http_upstream_get_peer(rrp->peers); ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get rr peer, current: %ui %i", rrp->current, rrp->peers->peer[rrp->current].current_weight); n = rrp->current / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << rrp->current % (8 * sizeof(uintptr_t)); if (!(rrp->tried[n] & m)) { peer = &rrp->peers->peer[rrp->current]; if (!peer->down) { if (peer->max_fails == 0 || peer->fails < peer->max_fails) { break; } if (now - peer->accessed > peer->fail_timeout) { peer->fails = 0; break; } peer->current_weight = 0; } else { rrp->tried[n] |= m; } pc->tries--; } if (pc->tries == 0) { goto failed; } if (--i == 0) { ngx_log_error(NGX_LOG_ALERT, pc->log, 0, "round robin upstream stuck on %ui tries", pc->tries); goto failed; } } peer->current_weight--; } else { i = pc->tries; for ( ;; ) { n = rrp->current / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << rrp->current % (8 * sizeof(uintptr_t)); if (!(rrp->tried[n] & m)) { peer = &rrp->peers->peer[rrp->current]; if (!peer->down) { if (peer->max_fails == 0 || peer->fails < peer->max_fails) { break; } if (now - peer->accessed > peer->fail_timeout) { peer->fails = 0; break; } peer->current_weight = 0; } else { rrp->tried[n] |= m; } pc->tries--; } rrp->current++; if (rrp->current >= rrp->peers->number) { rrp->current = 0; } if (pc->tries == 0) { goto failed; } if (--i == 0) { ngx_log_error(NGX_LOG_ALERT, pc->log, 0, "round robin upstream stuck on %ui tries", pc->tries); goto failed; } } peer->current_weight--; } rrp->tried[n] |= m; } pc->sockaddr = peer->sockaddr; pc->socklen = peer->socklen; pc->name = &peer->name; /* ngx_unlock_mutex(rrp->peers->mutex); */ if (pc->tries == 1 && rrp->peers->next) { pc->tries += rrp->peers->next->number; n = rrp->peers->next->number / (8 * sizeof(uintptr_t)) + 1; for (i = 0; i < n; i++) { rrp->tried[i] = 0; } } return NGX_OK; failed: peers = rrp->peers; if (peers->next) { /* ngx_unlock_mutex(peers->mutex); */ ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0, "backup servers"); rrp->peers = peers->next; pc->tries = rrp->peers->number; n = rrp->peers->number / (8 * sizeof(uintptr_t)) + 1; for (i = 0; i < n; i++) { rrp->tried[i] = 0; } rc = ngx_http_upstream_get_round_robin_peer(pc, rrp); if (rc != NGX_BUSY) { return rc; } /* ngx_lock_mutex(peers->mutex); */ } /* all peers failed, mark them as live for quick recovery */ for (i = 0; i < peers->number; i++) { peers->peer[i].fails = 0; } /* ngx_unlock_mutex(peers->mutex); */ pc->name = peers->name; return NGX_BUSY; } static ngx_uint_t ngx_http_upstream_get_peer(ngx_http_upstream_rr_peers_t *peers) { ngx_uint_t i, n; ngx_http_upstream_rr_peer_t *peer; peer = &peers->peer[0]; for ( ;; ) { for (i = 0; i < peers->number; i++) { if (peer[i].current_weight <= 0) { continue; } n = i; while (i < peers->number - 1) { i++; if (peer[i].current_weight <= 0) { continue; } if (peer[n].current_weight * 1000 / peer[i].current_weight > peer[n].weight * 1000 / peer[i].weight) { return n; } n = i; } if (peer[i].current_weight > 0) { n = i; } return n; } for (i = 0; i < peers->number; i++) { peer[i].current_weight = peer[i].weight; } } } 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); if (state == 0 && pc->tries == 0) { return; } /* TODO: NGX_PEER_KEEPALIVE */ if (rrp->peers->single) { pc->tries = 0; return; } if (state & NGX_PEER_FAILED) { now = ngx_time(); peer = &rrp->peers->peer[rrp->current]; /* ngx_lock_mutex(rrp->peers->mutex); */ peer->fails++; peer->accessed = now; if (peer->max_fails) { peer->current_weight -= peer->weight / peer->max_fails; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "free rr peer failed: %ui %i", rrp->current, peer->current_weight); if (peer->current_weight < 0) { peer->current_weight = 0; } /* ngx_unlock_mutex(rrp->peers->mutex); */ } rrp->current++; if (rrp->current >= rrp->peers->number) { rrp->current = 0; } if (pc->tries) { pc->tries--; } /* ngx_unlock_mutex(rrp->peers->mutex); */ } #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; peer = &rrp->peers->peer[rrp->current]; /* TODO: threads only mutex */ /* ngx_lock_mutex(rrp->peers->mutex); */ ssl_session = peer->ssl_session; rc = ngx_ssl_set_session(pc->connection, ssl_session); ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "set session: %p:%d", ssl_session, ssl_session ? ssl_session->references : 0); /* ngx_unlock_mutex(rrp->peers->mutex); */ 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; ssl_session = ngx_ssl_get_session(pc->connection); if (ssl_session == NULL) { return; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "save session: %p:%d", ssl_session, ssl_session->references); peer = &rrp->peers->peer[rrp->current]; /* TODO: threads only mutex */ /* ngx_lock_mutex(rrp->peers->mutex); */ old_ssl_session = peer->ssl_session; peer->ssl_session = ssl_session; /* ngx_unlock_mutex(rrp->peers->mutex); */ if (old_ssl_session) { ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "old session: %p:%d", old_ssl_session, old_ssl_session->references); /* TODO: may block */ ngx_ssl_free_session(old_ssl_session); } } #endif