1
2 /*
3 * Copyright (C) Igor Sysoev
4 * Copyright (C) Nginx, Inc.
5 */
6
7
8 #include <ngx_config.h>
9 #include <ngx_core.h>
10 #include <ngx_http.h>
11
12
13 typedef struct {
14 /* the round robin data must be first */
15 ngx_http_upstream_rr_peer_data_t rrp;
16
17 ngx_uint_t hash;
18
19 u_char addrlen;
20 u_char *addr;
21
22 u_char tries;
23
24 ngx_event_get_peer_pt get_rr_peer;
25 } ngx_http_upstream_ip_hash_peer_data_t;
26
27
28 static ngx_int_t ngx_http_upstream_init_ip_hash_peer(ngx_http_request_t *r,
29 ngx_http_upstream_srv_conf_t *us);
30 static ngx_int_t ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc,
31 void *data);
32 static char *ngx_http_upstream_ip_hash(ngx_conf_t *cf, ngx_command_t *cmd,
33 void *conf);
34
35
36 static ngx_command_t ngx_http_upstream_ip_hash_commands[] = {
37
38 { ngx_string("ip_hash"),
39 NGX_HTTP_UPS_CONF|NGX_CONF_NOARGS,
40 ngx_http_upstream_ip_hash,
41 0,
42 0,
43 NULL },
44
45 ngx_null_command
46 };
47
48
49 static ngx_http_module_t ngx_http_upstream_ip_hash_module_ctx = {
50 NULL, /* preconfiguration */
51 NULL, /* postconfiguration */
52
53 NULL, /* create main configuration */
54 NULL, /* init main configuration */
55
56 NULL, /* create server configuration */
57 NULL, /* merge server configuration */
58
59 NULL, /* create location configuration */
60 NULL /* merge location configuration */
61 };
62
63
64 ngx_module_t ngx_http_upstream_ip_hash_module = {
65 NGX_MODULE_V1,
66 &ngx_http_upstream_ip_hash_module_ctx, /* module context */
67 ngx_http_upstream_ip_hash_commands, /* module directives */
68 NGX_HTTP_MODULE, /* module type */
69 NULL, /* init master */
70 NULL, /* init module */
71 NULL, /* init process */
72 NULL, /* init thread */
73 NULL, /* exit thread */
74 NULL, /* exit process */
75 NULL, /* exit master */
76 NGX_MODULE_V1_PADDING
77 };
78
79
80 static u_char ngx_http_upstream_ip_hash_pseudo_addr[3];
81
82
83 static ngx_int_t
84 ngx_http_upstream_init_ip_hash(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us)
85 {
86 if (ngx_http_upstream_init_round_robin(cf, us) != NGX_OK) {
87 return NGX_ERROR;
88 }
89
90 us->peer.init = ngx_http_upstream_init_ip_hash_peer;
91
92 return NGX_OK;
93 }
94
95
96 static ngx_int_t
97 ngx_http_upstream_init_ip_hash_peer(ngx_http_request_t *r,
98 ngx_http_upstream_srv_conf_t *us)
99 {
100 struct sockaddr_in *sin;
101 #if (NGX_HAVE_INET6)
102 struct sockaddr_in6 *sin6;
103 #endif
104 ngx_http_upstream_ip_hash_peer_data_t *iphp;
105
106 iphp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_ip_hash_peer_data_t));
107 if (iphp == NULL) {
108 return NGX_ERROR;
109 }
110
111 r->upstream->peer.data = &iphp->rrp;
112
113 if (ngx_http_upstream_init_round_robin_peer(r, us) != NGX_OK) {
114 return NGX_ERROR;
115 }
116
117 r->upstream->peer.get = ngx_http_upstream_get_ip_hash_peer;
118
119 switch (r->connection->sockaddr->sa_family) {
120
121 case AF_INET:
122 sin = (struct sockaddr_in *) r->connection->sockaddr;
123 iphp->addr = (u_char *) &sin->sin_addr.s_addr;
124 iphp->addrlen = 3;
125 break;
126
127 #if (NGX_HAVE_INET6)
128 case AF_INET6:
129 sin6 = (struct sockaddr_in6 *) r->connection->sockaddr;
130 iphp->addr = (u_char *) &sin6->sin6_addr.s6_addr;
131 iphp->addrlen = 16;
132 break;
133 #endif
134
135 default:
136 iphp->addr = ngx_http_upstream_ip_hash_pseudo_addr;
137 iphp->addrlen = 3;
138 }
139
140 iphp->hash = 89;
141 iphp->tries = 0;
142 iphp->get_rr_peer = ngx_http_upstream_get_round_robin_peer;
143
144 return NGX_OK;
145 }
146
147
148 static ngx_int_t
149 ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc, void *data)
150 {
151 ngx_http_upstream_ip_hash_peer_data_t *iphp = data;
152
153 time_t now;
154 ngx_int_t w;
155 uintptr_t m;
156 ngx_uint_t i, n, p, hash;
157 ngx_http_upstream_rr_peer_t *peer;
158
159 ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
160 "get ip hash peer, try: %ui", pc->tries);
161
162 /* TODO: cached */
163
164 if (iphp->tries > 20 || iphp->rrp.peers->single) {
165 return iphp->get_rr_peer(pc, &iphp->rrp);
166 }
167
168 now = ngx_time();
169
170 pc->cached = 0;
171 pc->connection = NULL;
172
173 hash = iphp->hash;
174
175 for ( ;; ) {
176
177 for (i = 0; i < iphp->addrlen; i++) {
178 hash = (hash * 113 + iphp->addr[i]) % 6271;
179 }
180
181 if (!iphp->rrp.peers->weighted) {
182 p = hash % iphp->rrp.peers->number;
183
184 } else {
185 w = hash % iphp->rrp.peers->total_weight;
186
187 for (i = 0; i < iphp->rrp.peers->number; i++) {
188 w -= iphp->rrp.peers->peer[i].weight;
189 if (w < 0) {
190 break;
191 }
192 }
193
194 p = i;
195 }
196
197 n = p / (8 * sizeof(uintptr_t));
198 m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t));
199
200 if (!(iphp->rrp.tried[n] & m)) {
201
202 ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0,
203 "get ip hash peer, hash: %ui %04XA", p, m);
204
205 peer = &iphp->rrp.peers->peer[p];
206
207 /* ngx_lock_mutex(iphp->rrp.peers->mutex); */
208
209 if (!peer->down) {
210
211 if (peer->max_fails == 0 || peer->fails < peer->max_fails) {
212 break;
213 }
214
215 if (now - peer->checked > peer->fail_timeout) {
216 peer->checked = now;
217 break;
218 }
219 }
220
221 iphp->rrp.tried[n] |= m;
222
223 /* ngx_unlock_mutex(iphp->rrp.peers->mutex); */
224
225 pc->tries--;
226 }
227
228 if (++iphp->tries >= 20) {
229 return iphp->get_rr_peer(pc, &iphp->rrp);
230 }
231 }
232
233 iphp->rrp.current = p;
234
235 pc->sockaddr = peer->sockaddr;
236 pc->socklen = peer->socklen;
237 pc->name = &peer->name;
238
239 /* ngx_unlock_mutex(iphp->rrp.peers->mutex); */
240
241 iphp->rrp.tried[n] |= m;
242 iphp->hash = hash;
243
244 return NGX_OK;
245 }
246
247
248 static char *
249 ngx_http_upstream_ip_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
250 {
251 ngx_http_upstream_srv_conf_t *uscf;
252
253 uscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_upstream_module);
254
255 if (uscf->peer.init_upstream) {
256 ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
257 "load balancing method redefined");
258 }
259
260 uscf->peer.init_upstream = ngx_http_upstream_init_ip_hash;
261
262 uscf->flags = NGX_HTTP_UPSTREAM_CREATE
263 |NGX_HTTP_UPSTREAM_WEIGHT
264 |NGX_HTTP_UPSTREAM_MAX_FAILS
265 |NGX_HTTP_UPSTREAM_FAIL_TIMEOUT
266 |NGX_HTTP_UPSTREAM_DOWN;
267
268 return NGX_CONF_OK;
269 }
270
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.