Mercurial > hg > nginx
view src/stream/ngx_stream_upstream_round_robin.c @ 7098:7bfbf73db920
Stream: relaxed next upstream condition (ticket #1317).
When switching to a next upstream, some buffers could be stuck in the middle
of the filter chain. A condition existed that raised an error when this
happened. As it turned out, this condition prevented switching to a next
upstream if ssl preread was used with the TCP protocol (see the ticket).
In fact, the condition does not make sense for TCP, since after successful
connection to an upstream switching to another upstream never happens. As for
UDP, the issue with stuck buffers is unlikely to happen, but is still possible.
Specifically, if a filter delays sending data to upstream.
The condition can be relaxed to only check the "buffered" bitmask of the
upstream connection. The new condition is simpler and fixes the ticket issue
as well. Additionally, the upstream_out chain is now reset for UDP prior to
connecting to a new upstream to prevent repeating the client data twice.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 11 Sep 2017 15:32:31 +0300 |
parents | 54cf51c4f07a |
children | 696df3ac27ac |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> #define ngx_stream_upstream_tries(p) ((p)->number \ + ((p)->next ? (p)->next->number : 0)) static ngx_stream_upstream_rr_peer_t *ngx_stream_upstream_get_peer( ngx_stream_upstream_rr_peer_data_t *rrp); static void ngx_stream_upstream_notify_round_robin_peer( ngx_peer_connection_t *pc, void *data, ngx_uint_t state); #if (NGX_STREAM_SSL) static ngx_int_t ngx_stream_upstream_set_round_robin_peer_session( ngx_peer_connection_t *pc, void *data); static void ngx_stream_upstream_save_round_robin_peer_session( ngx_peer_connection_t *pc, void *data); static ngx_int_t ngx_stream_upstream_empty_set_session( ngx_peer_connection_t *pc, void *data); static void ngx_stream_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data); #endif ngx_int_t ngx_stream_upstream_init_round_robin(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us) { ngx_url_t u; ngx_uint_t i, j, n, w; ngx_stream_upstream_server_t *server; ngx_stream_upstream_rr_peer_t *peer, **peerp; ngx_stream_upstream_rr_peers_t *peers, *backup; us->peer.init = ngx_stream_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_stream_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_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_stream_upstream_rr_peers_t)); if (backup == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_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_stream_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_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_stream_upstream_init_round_robin_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us) { ngx_uint_t n; ngx_stream_upstream_rr_peer_data_t *rrp; rrp = s->upstream->peer.data; if (rrp == NULL) { rrp = ngx_palloc(s->connection->pool, sizeof(ngx_stream_upstream_rr_peer_data_t)); if (rrp == NULL) { return NGX_ERROR; } s->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(s->connection->pool, n * sizeof(uintptr_t)); if (rrp->tried == NULL) { return NGX_ERROR; } } s->upstream->peer.get = ngx_stream_upstream_get_round_robin_peer; s->upstream->peer.free = ngx_stream_upstream_free_round_robin_peer; s->upstream->peer.notify = ngx_stream_upstream_notify_round_robin_peer; s->upstream->peer.tries = ngx_stream_upstream_tries(rrp->peers); #if (NGX_STREAM_SSL) s->upstream->peer.set_session = ngx_stream_upstream_set_round_robin_peer_session; s->upstream->peer.save_session = ngx_stream_upstream_save_round_robin_peer_session; #endif return NGX_OK; } ngx_int_t ngx_stream_upstream_create_round_robin_peer(ngx_stream_session_t *s, ngx_stream_upstream_resolved_t *ur) { u_char *p; size_t len; socklen_t socklen; ngx_uint_t i, n; struct sockaddr *sockaddr; ngx_stream_upstream_rr_peer_t *peer, **peerp; ngx_stream_upstream_rr_peers_t *peers; ngx_stream_upstream_rr_peer_data_t *rrp; rrp = s->upstream->peer.data; if (rrp == NULL) { rrp = ngx_palloc(s->connection->pool, sizeof(ngx_stream_upstream_rr_peer_data_t)); if (rrp == NULL) { return NGX_ERROR; } s->upstream->peer.data = rrp; } peers = ngx_pcalloc(s->connection->pool, sizeof(ngx_stream_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(s->connection->pool, sizeof(ngx_stream_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; 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(s->connection->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(s->connection->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(s->connection->pool, n * sizeof(uintptr_t)); if (rrp->tried == NULL) { return NGX_ERROR; } } s->upstream->peer.get = ngx_stream_upstream_get_round_robin_peer; s->upstream->peer.free = ngx_stream_upstream_free_round_robin_peer; s->upstream->peer.tries = ngx_stream_upstream_tries(rrp->peers); #if (NGX_STREAM_SSL) s->upstream->peer.set_session = ngx_stream_upstream_empty_set_session; s->upstream->peer.save_session = ngx_stream_upstream_empty_save_session; #endif return NGX_OK; } ngx_int_t ngx_stream_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_rr_peer_data_t *rrp = data; ngx_int_t rc; ngx_uint_t i, n; ngx_stream_upstream_rr_peer_t *peer; ngx_stream_upstream_rr_peers_t *peers; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get rr peer, try: %ui", pc->tries); pc->connection = NULL; peers = rrp->peers; ngx_stream_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_stream_upstream_get_peer(rrp); if (peer == NULL) { goto failed; } ngx_log_debug2(NGX_LOG_DEBUG_STREAM, 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_stream_upstream_rr_peers_unlock(peers); return NGX_OK; failed: if (peers->next) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, 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_stream_upstream_rr_peers_unlock(peers); rc = ngx_stream_upstream_get_round_robin_peer(pc, rrp); if (rc != NGX_BUSY) { return rc; } ngx_stream_upstream_rr_peers_wlock(peers); } ngx_stream_upstream_rr_peers_unlock(peers); pc->name = peers->name; return NGX_BUSY; } static ngx_stream_upstream_rr_peer_t * ngx_stream_upstream_get_peer(ngx_stream_upstream_rr_peer_data_t *rrp) { time_t now; uintptr_t m; ngx_int_t total; ngx_uint_t i, n, p; ngx_stream_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_stream_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data, ngx_uint_t state) { ngx_stream_upstream_rr_peer_data_t *rrp = data; time_t now; ngx_stream_upstream_rr_peer_t *peer; ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0, "free rr peer %ui %ui", pc->tries, state); peer = rrp->current; ngx_stream_upstream_rr_peers_rlock(rrp->peers); ngx_stream_upstream_rr_peer_lock(rrp->peers, peer); if (rrp->peers->single) { peer->conns--; ngx_stream_upstream_rr_peer_unlock(rrp->peers, peer); ngx_stream_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_STREAM, 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_stream_upstream_rr_peer_unlock(rrp->peers, peer); ngx_stream_upstream_rr_peers_unlock(rrp->peers); if (pc->tries) { pc->tries--; } } static void ngx_stream_upstream_notify_round_robin_peer(ngx_peer_connection_t *pc, void *data, ngx_uint_t type) { ngx_stream_upstream_rr_peer_data_t *rrp = data; ngx_stream_upstream_rr_peer_t *peer; peer = rrp->current; if (type == NGX_STREAM_UPSTREAM_NOTIFY_CONNECT && pc->connection->type == SOCK_STREAM) { ngx_stream_upstream_rr_peers_rlock(rrp->peers); ngx_stream_upstream_rr_peer_lock(rrp->peers, peer); if (peer->accessed < peer->checked) { peer->fails = 0; } ngx_stream_upstream_rr_peer_unlock(rrp->peers, peer); ngx_stream_upstream_rr_peers_unlock(rrp->peers); } } #if (NGX_STREAM_SSL) static ngx_int_t ngx_stream_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_rr_peer_data_t *rrp = data; ngx_int_t rc; ngx_ssl_session_t *ssl_session; ngx_stream_upstream_rr_peer_t *peer; #if (NGX_STREAM_UPSTREAM_ZONE) int len; #if OPENSSL_VERSION_NUMBER >= 0x0090707fL const #endif u_char *p; ngx_stream_upstream_rr_peers_t *peers; u_char buf[NGX_SSL_MAX_SESSION_SIZE]; #endif peer = rrp->current; #if (NGX_STREAM_UPSTREAM_ZONE) peers = rrp->peers; if (peers->shpool) { ngx_stream_upstream_rr_peers_rlock(peers); ngx_stream_upstream_rr_peer_lock(peers, peer); if (peer->ssl_session == NULL) { ngx_stream_upstream_rr_peer_unlock(peers, peer); ngx_stream_upstream_rr_peers_unlock(peers); return NGX_OK; } len = peer->ssl_session_len; ngx_memcpy(buf, peer->ssl_session, len); ngx_stream_upstream_rr_peer_unlock(peers, peer); ngx_stream_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_STREAM, 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_STREAM, pc->log, 0, "set session: %p", ssl_session); return rc; } static void ngx_stream_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_rr_peer_data_t *rrp = data; ngx_ssl_session_t *old_ssl_session, *ssl_session; ngx_stream_upstream_rr_peer_t *peer; #if (NGX_STREAM_UPSTREAM_ZONE) int len; u_char *p; ngx_stream_upstream_rr_peers_t *peers; u_char buf[NGX_SSL_MAX_SESSION_SIZE]; #endif #if (NGX_STREAM_UPSTREAM_ZONE) peers = rrp->peers; if (peers->shpool) { ssl_session = SSL_get0_session(pc->connection->ssl->connection); if (ssl_session == NULL) { return; } ngx_log_debug1(NGX_LOG_DEBUG_STREAM, 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_stream_upstream_rr_peers_rlock(peers); ngx_stream_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_stream_upstream_rr_peer_unlock(peers, peer); ngx_stream_upstream_rr_peers_unlock(peers); return; } peer->ssl_session_len = len; } ngx_memcpy(peer->ssl_session, buf, len); ngx_stream_upstream_rr_peer_unlock(peers, peer); ngx_stream_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_STREAM, 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_STREAM, pc->log, 0, "old session: %p", old_ssl_session); /* TODO: may block */ ngx_ssl_free_session(old_ssl_session); } } static ngx_int_t ngx_stream_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data) { return NGX_OK; } static void ngx_stream_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data) { return; } #endif