Mercurial > hg > nginx
annotate src/stream/ngx_stream_upstream_least_conn_module.c @ 6704:a44ba757851d
Upstream: removed the quick recovery mechanism.
Its usefulness it questionable, and it interacts badly with max_conns.
| author | Ruslan Ermilov <ru@nginx.com> |
|---|---|
| date | Thu, 22 Sep 2016 19:32:45 +0300 |
| parents | 914d8a63dbad |
| children | 29bf0dbc0a77 |
| rev | line source |
|---|---|
| 6115 | 1 |
| 2 /* | |
| 3 * Copyright (C) Maxim Dounin | |
| 4 * Copyright (C) Nginx, Inc. | |
| 5 */ | |
| 6 | |
| 7 | |
| 8 #include <ngx_config.h> | |
| 9 #include <ngx_core.h> | |
| 10 #include <ngx_stream.h> | |
| 11 | |
| 12 | |
| 13 static ngx_int_t ngx_stream_upstream_init_least_conn_peer( | |
| 14 ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us); | |
| 15 static ngx_int_t ngx_stream_upstream_get_least_conn_peer( | |
| 16 ngx_peer_connection_t *pc, void *data); | |
| 17 static char *ngx_stream_upstream_least_conn(ngx_conf_t *cf, ngx_command_t *cmd, | |
| 18 void *conf); | |
| 19 | |
| 20 | |
| 21 static ngx_command_t ngx_stream_upstream_least_conn_commands[] = { | |
| 22 | |
| 23 { ngx_string("least_conn"), | |
| 24 NGX_STREAM_UPS_CONF|NGX_CONF_NOARGS, | |
| 25 ngx_stream_upstream_least_conn, | |
| 26 0, | |
| 27 0, | |
| 28 NULL }, | |
| 29 | |
| 30 ngx_null_command | |
| 31 }; | |
| 32 | |
| 33 | |
| 34 static ngx_stream_module_t ngx_stream_upstream_least_conn_module_ctx = { | |
|
6606
2f41d383c9c7
Stream: added preconfiguration step.
Vladimir Homutov <vl@nginx.com>
parents:
6474
diff
changeset
|
35 NULL, /* preconfiguration */ |
|
6174
68c106e6fa0a
Stream: added postconfiguration method to stream modules.
Vladimir Homutov <vl@nginx.com>
parents:
6115
diff
changeset
|
36 NULL, /* postconfiguration */ |
|
68c106e6fa0a
Stream: added postconfiguration method to stream modules.
Vladimir Homutov <vl@nginx.com>
parents:
6115
diff
changeset
|
37 |
| 6115 | 38 NULL, /* create main configuration */ |
| 39 NULL, /* init main configuration */ | |
| 40 | |
| 41 NULL, /* create server configuration */ | |
| 6629 | 42 NULL /* merge server configuration */ |
| 6115 | 43 }; |
| 44 | |
| 45 | |
| 46 ngx_module_t ngx_stream_upstream_least_conn_module = { | |
| 47 NGX_MODULE_V1, | |
| 48 &ngx_stream_upstream_least_conn_module_ctx, /* module context */ | |
| 49 ngx_stream_upstream_least_conn_commands, /* module directives */ | |
| 50 NGX_STREAM_MODULE, /* module type */ | |
| 51 NULL, /* init master */ | |
| 52 NULL, /* init module */ | |
| 53 NULL, /* init process */ | |
| 54 NULL, /* init thread */ | |
| 55 NULL, /* exit thread */ | |
| 56 NULL, /* exit process */ | |
| 57 NULL, /* exit master */ | |
| 58 NGX_MODULE_V1_PADDING | |
| 59 }; | |
| 60 | |
| 61 | |
| 62 static ngx_int_t | |
| 63 ngx_stream_upstream_init_least_conn(ngx_conf_t *cf, | |
| 64 ngx_stream_upstream_srv_conf_t *us) | |
| 65 { | |
| 66 ngx_log_debug0(NGX_LOG_DEBUG_STREAM, cf->log, 0, | |
| 67 "init least conn"); | |
| 68 | |
| 69 if (ngx_stream_upstream_init_round_robin(cf, us) != NGX_OK) { | |
| 70 return NGX_ERROR; | |
| 71 } | |
| 72 | |
| 73 us->peer.init = ngx_stream_upstream_init_least_conn_peer; | |
| 74 | |
| 75 return NGX_OK; | |
| 76 } | |
| 77 | |
| 78 | |
| 79 static ngx_int_t | |
| 80 ngx_stream_upstream_init_least_conn_peer(ngx_stream_session_t *s, | |
| 81 ngx_stream_upstream_srv_conf_t *us) | |
| 82 { | |
| 83 ngx_log_debug0(NGX_LOG_DEBUG_STREAM, s->connection->log, 0, | |
| 84 "init least conn peer"); | |
| 85 | |
| 86 if (ngx_stream_upstream_init_round_robin_peer(s, us) != NGX_OK) { | |
| 87 return NGX_ERROR; | |
| 88 } | |
| 89 | |
| 90 s->upstream->peer.get = ngx_stream_upstream_get_least_conn_peer; | |
| 91 | |
| 92 return NGX_OK; | |
| 93 } | |
| 94 | |
| 95 | |
| 96 static ngx_int_t | |
| 97 ngx_stream_upstream_get_least_conn_peer(ngx_peer_connection_t *pc, void *data) | |
| 98 { | |
| 99 ngx_stream_upstream_rr_peer_data_t *rrp = data; | |
| 100 | |
| 101 time_t now; | |
| 102 uintptr_t m; | |
| 103 ngx_int_t rc, total; | |
| 104 ngx_uint_t i, n, p, many; | |
| 105 ngx_stream_upstream_rr_peer_t *peer, *best; | |
| 106 ngx_stream_upstream_rr_peers_t *peers; | |
| 107 | |
| 108 ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, | |
| 109 "get least conn peer, try: %ui", pc->tries); | |
| 110 | |
| 111 if (rrp->peers->single) { | |
| 112 return ngx_stream_upstream_get_round_robin_peer(pc, rrp); | |
| 113 } | |
| 114 | |
| 115 pc->connection = NULL; | |
| 116 | |
| 117 now = ngx_time(); | |
| 118 | |
| 119 peers = rrp->peers; | |
| 120 | |
| 121 ngx_stream_upstream_rr_peers_wlock(peers); | |
| 122 | |
| 123 best = NULL; | |
| 124 total = 0; | |
| 125 | |
| 126 #if (NGX_SUPPRESS_WARN) | |
| 127 many = 0; | |
| 128 p = 0; | |
| 129 #endif | |
| 130 | |
| 131 for (peer = peers->peer, i = 0; | |
| 132 peer; | |
| 133 peer = peer->next, i++) | |
| 134 { | |
| 135 n = i / (8 * sizeof(uintptr_t)); | |
| 136 m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t)); | |
| 137 | |
| 138 if (rrp->tried[n] & m) { | |
| 139 continue; | |
| 140 } | |
| 141 | |
| 142 if (peer->down) { | |
| 143 continue; | |
| 144 } | |
| 145 | |
| 146 if (peer->max_fails | |
| 147 && peer->fails >= peer->max_fails | |
| 148 && now - peer->checked <= peer->fail_timeout) | |
| 149 { | |
| 150 continue; | |
| 151 } | |
| 152 | |
| 153 /* | |
| 154 * select peer with least number of connections; if there are | |
| 155 * multiple peers with the same number of connections, select | |
| 156 * based on round-robin | |
| 157 */ | |
| 158 | |
| 159 if (best == NULL | |
| 160 || peer->conns * best->weight < best->conns * peer->weight) | |
| 161 { | |
| 162 best = peer; | |
| 163 many = 0; | |
| 164 p = i; | |
| 165 | |
| 166 } else if (peer->conns * best->weight == best->conns * peer->weight) { | |
| 167 many = 1; | |
| 168 } | |
| 169 } | |
| 170 | |
| 171 if (best == NULL) { | |
| 172 ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0, | |
| 173 "get least conn peer, no peer found"); | |
| 174 | |
| 175 goto failed; | |
| 176 } | |
| 177 | |
| 178 if (many) { | |
| 179 ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0, | |
| 180 "get least conn peer, many"); | |
| 181 | |
| 182 for (peer = best, i = p; | |
| 183 peer; | |
| 184 peer = peer->next, i++) | |
| 185 { | |
| 186 n = i / (8 * sizeof(uintptr_t)); | |
| 187 m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t)); | |
| 188 | |
| 189 if (rrp->tried[n] & m) { | |
| 190 continue; | |
| 191 } | |
| 192 | |
| 193 if (peer->down) { | |
| 194 continue; | |
| 195 } | |
| 196 | |
| 197 if (peer->conns * best->weight != best->conns * peer->weight) { | |
| 198 continue; | |
| 199 } | |
| 200 | |
| 201 if (peer->max_fails | |
| 202 && peer->fails >= peer->max_fails | |
| 203 && now - peer->checked <= peer->fail_timeout) | |
| 204 { | |
| 205 continue; | |
| 206 } | |
| 207 | |
| 208 peer->current_weight += peer->effective_weight; | |
| 209 total += peer->effective_weight; | |
| 210 | |
| 211 if (peer->effective_weight < peer->weight) { | |
| 212 peer->effective_weight++; | |
| 213 } | |
| 214 | |
| 215 if (peer->current_weight > best->current_weight) { | |
| 216 best = peer; | |
| 217 p = i; | |
| 218 } | |
| 219 } | |
| 220 } | |
| 221 | |
| 222 best->current_weight -= total; | |
| 223 | |
| 224 if (now - best->checked > best->fail_timeout) { | |
| 225 best->checked = now; | |
| 226 } | |
| 227 | |
| 228 pc->sockaddr = best->sockaddr; | |
| 229 pc->socklen = best->socklen; | |
| 230 pc->name = &best->name; | |
| 231 | |
| 232 best->conns++; | |
| 233 | |
| 234 rrp->current = best; | |
| 235 | |
| 236 n = p / (8 * sizeof(uintptr_t)); | |
| 237 m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t)); | |
| 238 | |
| 239 rrp->tried[n] |= m; | |
| 240 | |
| 241 ngx_stream_upstream_rr_peers_unlock(peers); | |
| 242 | |
| 243 return NGX_OK; | |
| 244 | |
| 245 failed: | |
| 246 | |
| 247 if (peers->next) { | |
| 248 ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0, | |
| 249 "get least conn peer, backup servers"); | |
| 250 | |
| 251 rrp->peers = peers->next; | |
| 252 | |
| 253 n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1)) | |
| 254 / (8 * sizeof(uintptr_t)); | |
| 255 | |
| 256 for (i = 0; i < n; i++) { | |
| 6474 | 257 rrp->tried[i] = 0; |
| 6115 | 258 } |
| 259 | |
| 260 ngx_stream_upstream_rr_peers_unlock(peers); | |
| 261 | |
| 262 rc = ngx_stream_upstream_get_least_conn_peer(pc, rrp); | |
| 263 | |
| 264 if (rc != NGX_BUSY) { | |
| 265 return rc; | |
| 266 } | |
| 267 | |
| 268 ngx_stream_upstream_rr_peers_wlock(peers); | |
| 269 } | |
| 270 | |
| 271 ngx_stream_upstream_rr_peers_unlock(peers); | |
| 272 | |
| 273 pc->name = peers->name; | |
| 274 | |
| 275 return NGX_BUSY; | |
| 276 } | |
| 277 | |
| 278 | |
| 279 static char * | |
| 280 ngx_stream_upstream_least_conn(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) | |
| 281 { | |
| 282 ngx_stream_upstream_srv_conf_t *uscf; | |
| 283 | |
| 284 uscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_upstream_module); | |
| 285 | |
| 286 if (uscf->peer.init_upstream) { | |
| 287 ngx_conf_log_error(NGX_LOG_WARN, cf, 0, | |
| 288 "load balancing method redefined"); | |
| 289 } | |
| 290 | |
| 291 uscf->peer.init_upstream = ngx_stream_upstream_init_least_conn; | |
| 292 | |
| 293 uscf->flags = NGX_STREAM_UPSTREAM_CREATE | |
| 294 |NGX_STREAM_UPSTREAM_WEIGHT | |
| 295 |NGX_STREAM_UPSTREAM_MAX_FAILS | |
| 296 |NGX_STREAM_UPSTREAM_FAIL_TIMEOUT | |
| 297 |NGX_STREAM_UPSTREAM_DOWN | |
| 298 |NGX_STREAM_UPSTREAM_BACKUP; | |
| 299 | |
| 300 return NGX_CONF_OK; | |
| 301 } |