Mercurial > hg > nginx
view src/http/modules/ngx_http_upstream_ip_hash_module.c @ 4694:5b5c07dee156
Upstream keepalive: "single" parameter deprecated.
The original idea was to optimize edge cases in case of interchangeable
backends, i.e. don't establish a new connection if we have any one
cached. This causes more harm than good though, as it screws up
underlying balancer's idea about backends used and may result in
various unexpected problems.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 18 Jun 2012 14:23:42 +0000 |
parents | 382c523d253a |
children | 441b2941a506 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { /* the round robin data must be first */ ngx_http_upstream_rr_peer_data_t rrp; ngx_uint_t hash; u_char addr[3]; u_char tries; ngx_event_get_peer_pt get_rr_peer; } ngx_http_upstream_ip_hash_peer_data_t; static ngx_int_t ngx_http_upstream_init_ip_hash_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us); static ngx_int_t ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc, void *data); static char *ngx_http_upstream_ip_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_upstream_ip_hash_commands[] = { { ngx_string("ip_hash"), NGX_HTTP_UPS_CONF|NGX_CONF_NOARGS, ngx_http_upstream_ip_hash, 0, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_upstream_ip_hash_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_upstream_ip_hash_module = { NGX_MODULE_V1, &ngx_http_upstream_ip_hash_module_ctx, /* module context */ ngx_http_upstream_ip_hash_commands, /* module directives */ NGX_HTTP_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 }; ngx_int_t ngx_http_upstream_init_ip_hash(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us) { if (ngx_http_upstream_init_round_robin(cf, us) != NGX_OK) { return NGX_ERROR; } us->peer.init = ngx_http_upstream_init_ip_hash_peer; return NGX_OK; } static ngx_int_t ngx_http_upstream_init_ip_hash_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us) { u_char *p; struct sockaddr_in *sin; ngx_http_upstream_ip_hash_peer_data_t *iphp; iphp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_ip_hash_peer_data_t)); if (iphp == NULL) { return NGX_ERROR; } r->upstream->peer.data = &iphp->rrp; if (ngx_http_upstream_init_round_robin_peer(r, us) != NGX_OK) { return NGX_ERROR; } r->upstream->peer.get = ngx_http_upstream_get_ip_hash_peer; /* AF_INET only */ if (r->connection->sockaddr->sa_family == AF_INET) { sin = (struct sockaddr_in *) r->connection->sockaddr; p = (u_char *) &sin->sin_addr.s_addr; iphp->addr[0] = p[0]; iphp->addr[1] = p[1]; iphp->addr[2] = p[2]; } else { iphp->addr[0] = 0; iphp->addr[1] = 0; iphp->addr[2] = 0; } iphp->hash = 89; iphp->tries = 0; iphp->get_rr_peer = ngx_http_upstream_get_round_robin_peer; return NGX_OK; } static ngx_int_t ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_ip_hash_peer_data_t *iphp = data; time_t now; ngx_int_t w; uintptr_t m; ngx_uint_t i, n, p, hash; ngx_http_upstream_rr_peer_t *peer; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get ip hash peer, try: %ui", pc->tries); /* TODO: cached */ if (iphp->tries > 20 || iphp->rrp.peers->single) { return iphp->get_rr_peer(pc, &iphp->rrp); } now = ngx_time(); pc->cached = 0; pc->connection = NULL; hash = iphp->hash; for ( ;; ) { for (i = 0; i < 3; i++) { hash = (hash * 113 + iphp->addr[i]) % 6271; } if (!iphp->rrp.peers->weighted) { p = hash % iphp->rrp.peers->number; } else { w = hash % iphp->rrp.peers->total_weight; for (i = 0; i < iphp->rrp.peers->number; i++) { w -= iphp->rrp.peers->peer[i].weight; if (w < 0) { break; } } p = i; } n = p / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t)); if (!(iphp->rrp.tried[n] & m)) { ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get ip hash peer, hash: %ui %04XA", p, m); peer = &iphp->rrp.peers->peer[p]; /* ngx_lock_mutex(iphp->rrp.peers->mutex); */ if (!peer->down) { if (peer->max_fails == 0 || peer->fails < peer->max_fails) { break; } if (now - peer->checked > peer->fail_timeout) { peer->checked = now; break; } } iphp->rrp.tried[n] |= m; /* ngx_unlock_mutex(iphp->rrp.peers->mutex); */ pc->tries--; } if (++iphp->tries >= 20) { return iphp->get_rr_peer(pc, &iphp->rrp); } } iphp->rrp.current = p; pc->sockaddr = peer->sockaddr; pc->socklen = peer->socklen; pc->name = &peer->name; /* ngx_unlock_mutex(iphp->rrp.peers->mutex); */ iphp->rrp.tried[n] |= m; iphp->hash = hash; return NGX_OK; } static char * ngx_http_upstream_ip_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_upstream_srv_conf_t *uscf; uscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_upstream_module); uscf->peer.init_upstream = ngx_http_upstream_init_ip_hash; uscf->flags = NGX_HTTP_UPSTREAM_CREATE |NGX_HTTP_UPSTREAM_WEIGHT |NGX_HTTP_UPSTREAM_MAX_FAILS |NGX_HTTP_UPSTREAM_FAIL_TIMEOUT |NGX_HTTP_UPSTREAM_DOWN; return NGX_CONF_OK; }