Mercurial > hg > nginx-quic
view src/stream/ngx_stream_upstream_least_conn_module.c @ 7377:d4448892a294
HTTP/2: flood detection.
Fixed uncontrolled memory growth in case peer is flooding us with
some frames (e.g., SETTINGS and PING) and doesn't read data. Fix
is to limit the number of allocated control frames.
author | Ruslan Ermilov <ru@nginx.com> |
---|---|
date | Tue, 06 Nov 2018 16:29:35 +0300 |
parents | 29bf0dbc0a77 |
children |
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/* * Copyright (C) Maxim Dounin * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> static ngx_int_t ngx_stream_upstream_init_least_conn_peer( ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us); static ngx_int_t ngx_stream_upstream_get_least_conn_peer( ngx_peer_connection_t *pc, void *data); static char *ngx_stream_upstream_least_conn(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_stream_upstream_least_conn_commands[] = { { ngx_string("least_conn"), NGX_STREAM_UPS_CONF|NGX_CONF_NOARGS, ngx_stream_upstream_least_conn, 0, 0, NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_upstream_least_conn_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_upstream_least_conn_module = { NGX_MODULE_V1, &ngx_stream_upstream_least_conn_module_ctx, /* module context */ ngx_stream_upstream_least_conn_commands, /* module directives */ NGX_STREAM_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_stream_upstream_init_least_conn(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, cf->log, 0, "init least conn"); if (ngx_stream_upstream_init_round_robin(cf, us) != NGX_OK) { return NGX_ERROR; } us->peer.init = ngx_stream_upstream_init_least_conn_peer; return NGX_OK; } static ngx_int_t ngx_stream_upstream_init_least_conn_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, s->connection->log, 0, "init least conn peer"); if (ngx_stream_upstream_init_round_robin_peer(s, us) != NGX_OK) { return NGX_ERROR; } s->upstream->peer.get = ngx_stream_upstream_get_least_conn_peer; return NGX_OK; } static ngx_int_t ngx_stream_upstream_get_least_conn_peer(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_rr_peer_data_t *rrp = data; time_t now; uintptr_t m; ngx_int_t rc, total; ngx_uint_t i, n, p, many; ngx_stream_upstream_rr_peer_t *peer, *best; ngx_stream_upstream_rr_peers_t *peers; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get least conn peer, try: %ui", pc->tries); if (rrp->peers->single) { return ngx_stream_upstream_get_round_robin_peer(pc, rrp); } pc->connection = NULL; now = ngx_time(); peers = rrp->peers; ngx_stream_upstream_rr_peers_wlock(peers); best = NULL; total = 0; #if (NGX_SUPPRESS_WARN) many = 0; p = 0; #endif for (peer = 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; } /* * select peer with least number of connections; if there are * multiple peers with the same number of connections, select * based on round-robin */ if (best == NULL || peer->conns * best->weight < best->conns * peer->weight) { best = peer; many = 0; p = i; } else if (peer->conns * best->weight == best->conns * peer->weight) { many = 1; } } if (best == NULL) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get least conn peer, no peer found"); goto failed; } if (many) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get least conn peer, many"); for (peer = best, i = p; 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->conns * best->weight != best->conns * peer->weight) { 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 (peer->current_weight > best->current_weight) { best = peer; p = i; } } } best->current_weight -= total; if (now - best->checked > best->fail_timeout) { best->checked = now; } pc->sockaddr = best->sockaddr; pc->socklen = best->socklen; pc->name = &best->name; best->conns++; rrp->current = best; n = p / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t)); rrp->tried[n] |= m; ngx_stream_upstream_rr_peers_unlock(peers); return NGX_OK; failed: if (peers->next) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get least conn peer, 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_least_conn_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 char * ngx_stream_upstream_least_conn(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_stream_upstream_srv_conf_t *uscf; uscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_upstream_module); if (uscf->peer.init_upstream) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "load balancing method redefined"); } uscf->peer.init_upstream = ngx_stream_upstream_init_least_conn; uscf->flags = NGX_STREAM_UPSTREAM_CREATE |NGX_STREAM_UPSTREAM_WEIGHT |NGX_STREAM_UPSTREAM_MAX_CONNS |NGX_STREAM_UPSTREAM_MAX_FAILS |NGX_STREAM_UPSTREAM_FAIL_TIMEOUT |NGX_STREAM_UPSTREAM_DOWN |NGX_STREAM_UPSTREAM_BACKUP; return NGX_CONF_OK; }