Mercurial > hg > nginx-quic
view src/stream/ngx_stream_upstream_least_conn_module.c @ 8551:c35b255d80dc quic
HTTP/3: close connection on keepalive_requests * 2.
After receiving GOAWAY, client is not supposed to create new streams. However,
until client reads this frame, we allow it to create new streams, which are
gracefully rejected. To prevent client from abusing this algorithm, a new
limit is introduced. Upon reaching keepalive_requests * 2, server now closes
the entire QUIC connection claiming excessive load.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Thu, 29 Jul 2021 16:01:37 +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; }