ngx_http_upstream_round_robin.c
/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#define ngx_http_upstream_tries(p) ((p)->number \
+ ((p)->next ? (p)->next->number : 0))
static ngx_http_upstream_rr_peer_t *ngx_http_upstream_get_peer(
ngx_http_upstream_rr_peer_data_t *rrp);
#if (NGX_HTTP_SSL)
static ngx_int_t ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc,
void *data);
static void ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc,
void *data);
#endif
ngx_int_t
ngx_http_upstream_init_round_robin(ngx_conf_t *cf,
ngx_http_upstream_srv_conf_t *us)
{
ngx_url_t u;
ngx_uint_t i, j, n, w;
ngx_http_upstream_server_t *server;
ngx_http_upstream_rr_peer_t *peer, **peerp;
ngx_http_upstream_rr_peers_t *peers, *backup;
us->peer.init = ngx_http_upstream_init_round_robin_peer;
if (us->servers) {
server = us->servers->elts;
n = 0;
w = 0;
for (i = 0; i < us->servers->nelts; i++) {
if (server[i].backup) {
continue;
}
n += server[i].naddrs;
w += server[i].naddrs * server[i].weight;
}
if (n == 0) {
ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
"no servers in upstream \"%V\" in %s:%ui",
&us->host, us->file_name, us->line);
return NGX_ERROR;
}
peers = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t));
if (peers == NULL) {
return NGX_ERROR;
}
peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peer_t) * n);
if (peer == NULL) {
return NGX_ERROR;
}
peers->single = (n == 1);
peers->number = n;
peers->weighted = (w != n);
peers->total_weight = w;
peers->name = &us->host;
n = 0;
peerp = &peers->peer;
for (i = 0; i < us->servers->nelts; i++) {
if (server[i].backup) {
continue;
}
for (j = 0; j < server[i].naddrs; j++) {
peer[n].sockaddr = server[i].addrs[j].sockaddr;
peer[n].socklen = server[i].addrs[j].socklen;
peer[n].name = server[i].addrs[j].name;
peer[n].weight = server[i].weight;
peer[n].effective_weight = server[i].weight;
peer[n].current_weight = 0;
peer[n].max_conns = server[i].max_conns;
peer[n].max_fails = server[i].max_fails;
peer[n].fail_timeout = server[i].fail_timeout;
peer[n].down = server[i].down;
peer[n].server = server[i].name;
*peerp = &peer[n];
peerp = &peer[n].next;
n++;
}
}
us->peer.data = peers;
/* backup servers */
n = 0;
w = 0;
for (i = 0; i < us->servers->nelts; i++) {
if (!server[i].backup) {
continue;
}
n += server[i].naddrs;
w += server[i].naddrs * server[i].weight;
}
if (n == 0) {
return NGX_OK;
}
backup = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t));
if (backup == NULL) {
return NGX_ERROR;
}
peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peer_t) * n);
if (peer == NULL) {
return NGX_ERROR;
}
peers->single = 0;
backup->single = 0;
backup->number = n;
backup->weighted = (w != n);
backup->total_weight = w;
backup->name = &us->host;
n = 0;
peerp = &backup->peer;
for (i = 0; i < us->servers->nelts; i++) {
if (!server[i].backup) {
continue;
}
for (j = 0; j < server[i].naddrs; j++) {
peer[n].sockaddr = server[i].addrs[j].sockaddr;
peer[n].socklen = server[i].addrs[j].socklen;
peer[n].name = server[i].addrs[j].name;
peer[n].weight = server[i].weight;
peer[n].effective_weight = server[i].weight;
peer[n].current_weight = 0;
peer[n].max_conns = server[i].max_conns;
peer[n].max_fails = server[i].max_fails;
peer[n].fail_timeout = server[i].fail_timeout;
peer[n].down = server[i].down;
peer[n].server = server[i].name;
*peerp = &peer[n];
peerp = &peer[n].next;
n++;
}
}
peers->next = backup;
return NGX_OK;
}
/* an upstream implicitly defined by proxy_pass, etc. */
if (us->port == 0) {
ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
"no port in upstream \"%V\" in %s:%ui",
&us->host, us->file_name, us->line);
return NGX_ERROR;
}
ngx_memzero(&u, sizeof(ngx_url_t));
u.host = us->host;
u.port = us->port;
if (ngx_inet_resolve_host(cf->pool, &u) != NGX_OK) {
if (u.err) {
ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
"%s in upstream \"%V\" in %s:%ui",
u.err, &us->host, us->file_name, us->line);
}
return NGX_ERROR;
}
n = u.naddrs;
peers = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peers_t));
if (peers == NULL) {
return NGX_ERROR;
}
peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_rr_peer_t) * n);
if (peer == NULL) {
return NGX_ERROR;
}
peers->single = (n == 1);
peers->number = n;
peers->weighted = 0;
peers->total_weight = n;
peers->name = &us->host;
peerp = &peers->peer;
for (i = 0; i < u.naddrs; i++) {
peer[i].sockaddr = u.addrs[i].sockaddr;
peer[i].socklen = u.addrs[i].socklen;
peer[i].name = u.addrs[i].name;
peer[i].weight = 1;
peer[i].effective_weight = 1;
peer[i].current_weight = 0;
peer[i].max_conns = 0;
peer[i].max_fails = 1;
peer[i].fail_timeout = 10;
*peerp = &peer[i];
peerp = &peer[i].next;
}
us->peer.data = peers;
/* implicitly defined upstream has no backup servers */
return NGX_OK;
}
ngx_int_t
ngx_http_upstream_init_round_robin_peer(ngx_http_request_t *r,
ngx_http_upstream_srv_conf_t *us)
{
ngx_uint_t n;
ngx_http_upstream_rr_peer_data_t *rrp;
rrp = r->upstream->peer.data;
if (rrp == NULL) {
rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t));
if (rrp == NULL) {
return NGX_ERROR;
}
r->upstream->peer.data = rrp;
}
rrp->peers = us->peer.data;
rrp->current = NULL;
rrp->config = 0;
n = rrp->peers->number;
if (rrp->peers->next && rrp->peers->next->number > n) {
n = rrp->peers->next->number;
}
if (n <= 8 * sizeof(uintptr_t)) {
rrp->tried = &rrp->data;
rrp->data = 0;
} else {
n = (n + (8 * sizeof(uintptr_t) - 1)) / (8 * sizeof(uintptr_t));
rrp->tried = ngx_pcalloc(r->pool, n * sizeof(uintptr_t));
if (rrp->tried == NULL) {
return NGX_ERROR;
}
}
r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer;
r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer;
r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers);
#if (NGX_HTTP_SSL)
r->upstream->peer.set_session =
ngx_http_upstream_set_round_robin_peer_session;
r->upstream->peer.save_session =
ngx_http_upstream_save_round_robin_peer_session;
#endif
return NGX_OK;
}
ngx_int_t
ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r,
ngx_http_upstream_resolved_t *ur)
{
u_char *p;
size_t len;
socklen_t socklen;
ngx_uint_t i, n;
struct sockaddr *sockaddr;
ngx_http_upstream_rr_peer_t *peer, **peerp;
ngx_http_upstream_rr_peers_t *peers;
ngx_http_upstream_rr_peer_data_t *rrp;
rrp = r->upstream->peer.data;
if (rrp == NULL) {
rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t));
if (rrp == NULL) {
return NGX_ERROR;
}
r->upstream->peer.data = rrp;
}
peers = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peers_t));
if (peers == NULL) {
return NGX_ERROR;
}
peer = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peer_t)
* ur->naddrs);
if (peer == NULL) {
return NGX_ERROR;
}
peers->single = (ur->naddrs == 1);
peers->number = ur->naddrs;
peers->name = &ur->host;
if (ur->sockaddr) {
peer[0].sockaddr = ur->sockaddr;
peer[0].socklen = ur->socklen;
peer[0].name = ur->name.data ? ur->name : ur->host;
peer[0].weight = 1;
peer[0].effective_weight = 1;
peer[0].current_weight = 0;
peer[0].max_conns = 0;
peer[0].max_fails = 1;
peer[0].fail_timeout = 10;
peers->peer = peer;
} else {
peerp = &peers->peer;
for (i = 0; i < ur->naddrs; i++) {
socklen = ur->addrs[i].socklen;
sockaddr = ngx_palloc(r->pool, socklen);
if (sockaddr == NULL) {
return NGX_ERROR;
}
ngx_memcpy(sockaddr, ur->addrs[i].sockaddr, socklen);
ngx_inet_set_port(sockaddr, ur->port);
p = ngx_pnalloc(r->pool, NGX_SOCKADDR_STRLEN);
if (p == NULL) {
return NGX_ERROR;
}
len = ngx_sock_ntop(sockaddr, socklen, p, NGX_SOCKADDR_STRLEN, 1);
peer[i].sockaddr = sockaddr;
peer[i].socklen = socklen;
peer[i].name.len = len;
peer[i].name.data = p;
peer[i].weight = 1;
peer[i].effective_weight = 1;
peer[i].current_weight = 0;
peer[i].max_conns = 0;
peer[i].max_fails = 1;
peer[i].fail_timeout = 10;
*peerp = &peer[i];
peerp = &peer[i].next;
}
}
rrp->peers = peers;
rrp->current = NULL;
rrp->config = 0;
if (rrp->peers->number <= 8 * sizeof(uintptr_t)) {
rrp->tried = &rrp->data;
rrp->data = 0;
} else {
n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1))
/ (8 * sizeof(uintptr_t));
rrp->tried = ngx_pcalloc(r->pool, n * sizeof(uintptr_t));
if (rrp->tried == NULL) {
return NGX_ERROR;
}
}
r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer;
r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer;
r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers);
#if (NGX_HTTP_SSL)
r->upstream->peer.set_session = ngx_http_upstream_empty_set_session;
r->upstream->peer.save_session = ngx_http_upstream_empty_save_session;
#endif
return NGX_OK;
}
ngx_int_t
ngx_http_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data)
{
ngx_http_upstream_rr_peer_data_t *rrp = data;
ngx_int_t rc;
ngx_uint_t i, n;
ngx_http_upstream_rr_peer_t *peer;
ngx_http_upstream_rr_peers_t *peers;
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"get rr peer, try: %ui", pc->tries);
pc->cached = 0;
pc->connection = NULL;
peers = rrp->peers;
ngx_http_upstream_rr_peers_wlock(peers);
if (peers->single) {
peer = peers->peer;
if (peer->down) {
goto failed;
}
if (peer->max_conns && peer->conns >= peer->max_conns) {
goto failed;
}
rrp->current = peer;
} else {
/* there are several peers */
peer = ngx_http_upstream_get_peer(rrp);
if (peer == NULL) {
goto failed;
}
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"get rr peer, current: %p %i",
peer, peer->current_weight);
}
pc->sockaddr = peer->sockaddr;
pc->socklen = peer->socklen;
pc->name = &peer->name;
peer->conns++;
ngx_http_upstream_rr_peers_unlock(peers);
return NGX_OK;
failed:
if (peers->next) {
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0, "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_http_upstream_rr_peers_unlock(peers);
rc = ngx_http_upstream_get_round_robin_peer(pc, rrp);
if (rc != NGX_BUSY) {
return rc;
}
ngx_http_upstream_rr_peers_wlock(peers);
}
ngx_http_upstream_rr_peers_unlock(peers);
pc->name = peers->name;
return NGX_BUSY;
}
static ngx_http_upstream_rr_peer_t *
ngx_http_upstream_get_peer(ngx_http_upstream_rr_peer_data_t *rrp)
{
time_t now;
uintptr_t m;
ngx_int_t total;
ngx_uint_t i, n, p;
ngx_http_upstream_rr_peer_t *peer, *best;
now = ngx_time();
best = NULL;
total = 0;
#if (NGX_SUPPRESS_WARN)
p = 0;
#endif
for (peer = rrp->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;
}
peer->current_weight += peer->effective_weight;
total += peer->effective_weight;
if (peer->effective_weight < peer->weight) {
peer->effective_weight++;
}
if (best == NULL || peer->current_weight > best->current_weight) {
best = peer;
p = i;
}
}
if (best == NULL) {
return NULL;
}
rrp->current = best;
n = p / (8 * sizeof(uintptr_t));
m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t));
rrp->tried[n] |= m;
best->current_weight -= total;
if (now - best->checked > best->fail_timeout) {
best->checked = now;
}
return best;
}
void
ngx_http_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data,
ngx_uint_t state)
{
ngx_http_upstream_rr_peer_data_t *rrp = data;
time_t now;
ngx_http_upstream_rr_peer_t *peer;
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"free rr peer %ui %ui", pc->tries, state);
/* TODO: NGX_PEER_KEEPALIVE */
peer = rrp->current;
ngx_http_upstream_rr_peers_rlock(rrp->peers);
ngx_http_upstream_rr_peer_lock(rrp->peers, peer);
if (rrp->peers->single) {
peer->conns--;
ngx_http_upstream_rr_peer_unlock(rrp->peers, peer);
ngx_http_upstream_rr_peers_unlock(rrp->peers);
pc->tries = 0;
return;
}
if (state & NGX_PEER_FAILED) {
now = ngx_time();
peer->fails++;
peer->accessed = now;
peer->checked = now;
if (peer->max_fails) {
peer->effective_weight -= peer->weight / peer->max_fails;
if (peer->fails >= peer->max_fails) {
ngx_log_error(NGX_LOG_WARN, pc->log, 0,
"upstream server temporarily disabled");
}
}
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"free rr peer failed: %p %i",
peer, peer->effective_weight);
if (peer->effective_weight < 0) {
peer->effective_weight = 0;
}
} else {
/* mark peer live if check passed */
if (peer->accessed < peer->checked) {
peer->fails = 0;
}
}
peer->conns--;
ngx_http_upstream_rr_peer_unlock(rrp->peers, peer);
ngx_http_upstream_rr_peers_unlock(rrp->peers);
if (pc->tries) {
pc->tries--;
}
}
#if (NGX_HTTP_SSL)
ngx_int_t
ngx_http_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc,
void *data)
{
ngx_http_upstream_rr_peer_data_t *rrp = data;
ngx_int_t rc;
ngx_ssl_session_t *ssl_session;
ngx_http_upstream_rr_peer_t *peer;
#if (NGX_HTTP_UPSTREAM_ZONE)
int len;
const u_char *p;
ngx_http_upstream_rr_peers_t *peers;
u_char buf[NGX_SSL_MAX_SESSION_SIZE];
#endif
peer = rrp->current;
#if (NGX_HTTP_UPSTREAM_ZONE)
peers = rrp->peers;
if (peers->shpool) {
ngx_http_upstream_rr_peers_rlock(peers);
ngx_http_upstream_rr_peer_lock(peers, peer);
if (peer->ssl_session == NULL) {
ngx_http_upstream_rr_peer_unlock(peers, peer);
ngx_http_upstream_rr_peers_unlock(peers);
return NGX_OK;
}
len = peer->ssl_session_len;
ngx_memcpy(buf, peer->ssl_session, len);
ngx_http_upstream_rr_peer_unlock(peers, peer);
ngx_http_upstream_rr_peers_unlock(peers);
p = buf;
ssl_session = d2i_SSL_SESSION(NULL, &p, len);
rc = ngx_ssl_set_session(pc->connection, ssl_session);
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"set session: %p", ssl_session);
ngx_ssl_free_session(ssl_session);
return rc;
}
#endif
ssl_session = peer->ssl_session;
rc = ngx_ssl_set_session(pc->connection, ssl_session);
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"set session: %p", ssl_session);
return rc;
}
void
ngx_http_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc,
void *data)
{
ngx_http_upstream_rr_peer_data_t *rrp = data;
ngx_ssl_session_t *old_ssl_session, *ssl_session;
ngx_http_upstream_rr_peer_t *peer;
#if (NGX_HTTP_UPSTREAM_ZONE)
int len;
u_char *p;
ngx_http_upstream_rr_peers_t *peers;
u_char buf[NGX_SSL_MAX_SESSION_SIZE];
#endif
#if (NGX_HTTP_UPSTREAM_ZONE)
peers = rrp->peers;
if (peers->shpool) {
ssl_session = ngx_ssl_get0_session(pc->connection);
if (ssl_session == NULL) {
return;
}
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"save session: %p", ssl_session);
len = i2d_SSL_SESSION(ssl_session, NULL);
/* do not cache too big session */
if (len > NGX_SSL_MAX_SESSION_SIZE) {
return;
}
p = buf;
(void) i2d_SSL_SESSION(ssl_session, &p);
peer = rrp->current;
ngx_http_upstream_rr_peers_rlock(peers);
ngx_http_upstream_rr_peer_lock(peers, peer);
if (len > peer->ssl_session_len) {
ngx_shmtx_lock(&peers->shpool->mutex);
if (peer->ssl_session) {
ngx_slab_free_locked(peers->shpool, peer->ssl_session);
}
peer->ssl_session = ngx_slab_alloc_locked(peers->shpool, len);
ngx_shmtx_unlock(&peers->shpool->mutex);
if (peer->ssl_session == NULL) {
peer->ssl_session_len = 0;
ngx_http_upstream_rr_peer_unlock(peers, peer);
ngx_http_upstream_rr_peers_unlock(peers);
return;
}
peer->ssl_session_len = len;
}
ngx_memcpy(peer->ssl_session, buf, len);
ngx_http_upstream_rr_peer_unlock(peers, peer);
ngx_http_upstream_rr_peers_unlock(peers);
return;
}
#endif
ssl_session = ngx_ssl_get_session(pc->connection);
if (ssl_session == NULL) {
return;
}
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"save session: %p", ssl_session);
peer = rrp->current;
old_ssl_session = peer->ssl_session;
peer->ssl_session = ssl_session;
if (old_ssl_session) {
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
"old session: %p", old_ssl_session);
/* TODO: may block */
ngx_ssl_free_session(old_ssl_session);
}
}
static ngx_int_t
ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data)
{
return NGX_OK;
}
static void
ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data)
{
return;
}
#endif
