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@vadv
Created October 18, 2012 22:15
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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;
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;
}
p = hash % iphp->rrp.peers->number;
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->accessed > peer->fail_timeout) {
peer->fails = 0;
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_MAX_FAILS
|NGX_HTTP_UPSTREAM_FAIL_TIMEOUT
|NGX_HTTP_UPSTREAM_DOWN;
return NGX_CONF_OK;
}
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