nginx/src/stream/ngx_stream_upstream_round_robin.c
Ruslan Ermilov cfa669151e Upstream: excluded down servers from the next_upstream tries.
Previously, the number of next_upstream tries included servers marked
as "down", resulting in "no live upstreams" with the code 502 instead
of the code derived from an attempt to connect to the last tried "up"
server (ticket #2096).
2020-11-27 00:01:20 +03:00

886 lines
23 KiB
C

/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_stream.h>
#define ngx_stream_upstream_tries(p) ((p)->tries \
+ ((p)->next ? (p)->next->tries : 0))
static ngx_stream_upstream_rr_peer_t *ngx_stream_upstream_get_peer(
ngx_stream_upstream_rr_peer_data_t *rrp);
static void ngx_stream_upstream_notify_round_robin_peer(
ngx_peer_connection_t *pc, void *data, ngx_uint_t state);
#if (NGX_STREAM_SSL)
static ngx_int_t ngx_stream_upstream_set_round_robin_peer_session(
ngx_peer_connection_t *pc, void *data);
static void ngx_stream_upstream_save_round_robin_peer_session(
ngx_peer_connection_t *pc, void *data);
static ngx_int_t ngx_stream_upstream_empty_set_session(
ngx_peer_connection_t *pc, void *data);
static void ngx_stream_upstream_empty_save_session(ngx_peer_connection_t *pc,
void *data);
#endif
ngx_int_t
ngx_stream_upstream_init_round_robin(ngx_conf_t *cf,
ngx_stream_upstream_srv_conf_t *us)
{
ngx_url_t u;
ngx_uint_t i, j, n, w, t;
ngx_stream_upstream_server_t *server;
ngx_stream_upstream_rr_peer_t *peer, **peerp;
ngx_stream_upstream_rr_peers_t *peers, *backup;
us->peer.init = ngx_stream_upstream_init_round_robin_peer;
if (us->servers) {
server = us->servers->elts;
n = 0;
w = 0;
t = 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 (!server[i].down) {
t += server[i].naddrs;
}
}
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_stream_upstream_rr_peers_t));
if (peers == NULL) {
return NGX_ERROR;
}
peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_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->tries = t;
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;
t = 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 (!server[i].down) {
t += server[i].naddrs;
}
}
if (n == 0) {
return NGX_OK;
}
backup = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peers_t));
if (backup == NULL) {
return NGX_ERROR;
}
peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_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->tries = t;
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_stream_upstream_rr_peers_t));
if (peers == NULL) {
return NGX_ERROR;
}
peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_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->tries = 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_stream_upstream_init_round_robin_peer(ngx_stream_session_t *s,
ngx_stream_upstream_srv_conf_t *us)
{
ngx_uint_t n;
ngx_stream_upstream_rr_peer_data_t *rrp;
rrp = s->upstream->peer.data;
if (rrp == NULL) {
rrp = ngx_palloc(s->connection->pool,
sizeof(ngx_stream_upstream_rr_peer_data_t));
if (rrp == NULL) {
return NGX_ERROR;
}
s->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(s->connection->pool, n * sizeof(uintptr_t));
if (rrp->tried == NULL) {
return NGX_ERROR;
}
}
s->upstream->peer.get = ngx_stream_upstream_get_round_robin_peer;
s->upstream->peer.free = ngx_stream_upstream_free_round_robin_peer;
s->upstream->peer.notify = ngx_stream_upstream_notify_round_robin_peer;
s->upstream->peer.tries = ngx_stream_upstream_tries(rrp->peers);
#if (NGX_STREAM_SSL)
s->upstream->peer.set_session =
ngx_stream_upstream_set_round_robin_peer_session;
s->upstream->peer.save_session =
ngx_stream_upstream_save_round_robin_peer_session;
#endif
return NGX_OK;
}
ngx_int_t
ngx_stream_upstream_create_round_robin_peer(ngx_stream_session_t *s,
ngx_stream_upstream_resolved_t *ur)
{
u_char *p;
size_t len;
socklen_t socklen;
ngx_uint_t i, n;
struct sockaddr *sockaddr;
ngx_stream_upstream_rr_peer_t *peer, **peerp;
ngx_stream_upstream_rr_peers_t *peers;
ngx_stream_upstream_rr_peer_data_t *rrp;
rrp = s->upstream->peer.data;
if (rrp == NULL) {
rrp = ngx_palloc(s->connection->pool,
sizeof(ngx_stream_upstream_rr_peer_data_t));
if (rrp == NULL) {
return NGX_ERROR;
}
s->upstream->peer.data = rrp;
}
peers = ngx_pcalloc(s->connection->pool,
sizeof(ngx_stream_upstream_rr_peers_t));
if (peers == NULL) {
return NGX_ERROR;
}
peer = ngx_pcalloc(s->connection->pool,
sizeof(ngx_stream_upstream_rr_peer_t) * ur->naddrs);
if (peer == NULL) {
return NGX_ERROR;
}
peers->single = (ur->naddrs == 1);
peers->number = ur->naddrs;
peers->tries = ur->naddrs;
peers->name = &ur->host;
if (ur->sockaddr) {
peer[0].sockaddr = ur->sockaddr;
peer[0].socklen = ur->socklen;
peer[0].name = ur->name;
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(s->connection->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(s->connection->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(s->connection->pool, n * sizeof(uintptr_t));
if (rrp->tried == NULL) {
return NGX_ERROR;
}
}
s->upstream->peer.get = ngx_stream_upstream_get_round_robin_peer;
s->upstream->peer.free = ngx_stream_upstream_free_round_robin_peer;
s->upstream->peer.tries = ngx_stream_upstream_tries(rrp->peers);
#if (NGX_STREAM_SSL)
s->upstream->peer.set_session = ngx_stream_upstream_empty_set_session;
s->upstream->peer.save_session = ngx_stream_upstream_empty_save_session;
#endif
return NGX_OK;
}
ngx_int_t
ngx_stream_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data)
{
ngx_stream_upstream_rr_peer_data_t *rrp = data;
ngx_int_t rc;
ngx_uint_t i, n;
ngx_stream_upstream_rr_peer_t *peer;
ngx_stream_upstream_rr_peers_t *peers;
ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
"get rr peer, try: %ui", pc->tries);
pc->connection = NULL;
peers = rrp->peers;
ngx_stream_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_stream_upstream_get_peer(rrp);
if (peer == NULL) {
goto failed;
}
ngx_log_debug2(NGX_LOG_DEBUG_STREAM, 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_stream_upstream_rr_peers_unlock(peers);
return NGX_OK;
failed:
if (peers->next) {
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, 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_stream_upstream_rr_peers_unlock(peers);
rc = ngx_stream_upstream_get_round_robin_peer(pc, rrp);
if (rc != NGX_BUSY) {
return rc;
}
ngx_stream_upstream_rr_peers_wlock(peers);
}
ngx_stream_upstream_rr_peers_unlock(peers);
pc->name = peers->name;
return NGX_BUSY;
}
static ngx_stream_upstream_rr_peer_t *
ngx_stream_upstream_get_peer(ngx_stream_upstream_rr_peer_data_t *rrp)
{
time_t now;
uintptr_t m;
ngx_int_t total;
ngx_uint_t i, n, p;
ngx_stream_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_stream_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data,
ngx_uint_t state)
{
ngx_stream_upstream_rr_peer_data_t *rrp = data;
time_t now;
ngx_stream_upstream_rr_peer_t *peer;
ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0,
"free rr peer %ui %ui", pc->tries, state);
peer = rrp->current;
ngx_stream_upstream_rr_peers_rlock(rrp->peers);
ngx_stream_upstream_rr_peer_lock(rrp->peers, peer);
if (rrp->peers->single) {
peer->conns--;
ngx_stream_upstream_rr_peer_unlock(rrp->peers, peer);
ngx_stream_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_STREAM, 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_stream_upstream_rr_peer_unlock(rrp->peers, peer);
ngx_stream_upstream_rr_peers_unlock(rrp->peers);
if (pc->tries) {
pc->tries--;
}
}
static void
ngx_stream_upstream_notify_round_robin_peer(ngx_peer_connection_t *pc,
void *data, ngx_uint_t type)
{
ngx_stream_upstream_rr_peer_data_t *rrp = data;
ngx_stream_upstream_rr_peer_t *peer;
peer = rrp->current;
if (type == NGX_STREAM_UPSTREAM_NOTIFY_CONNECT
&& pc->connection->type == SOCK_STREAM)
{
ngx_stream_upstream_rr_peers_rlock(rrp->peers);
ngx_stream_upstream_rr_peer_lock(rrp->peers, peer);
if (peer->accessed < peer->checked) {
peer->fails = 0;
}
ngx_stream_upstream_rr_peer_unlock(rrp->peers, peer);
ngx_stream_upstream_rr_peers_unlock(rrp->peers);
}
}
#if (NGX_STREAM_SSL)
static ngx_int_t
ngx_stream_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc,
void *data)
{
ngx_stream_upstream_rr_peer_data_t *rrp = data;
ngx_int_t rc;
ngx_ssl_session_t *ssl_session;
ngx_stream_upstream_rr_peer_t *peer;
#if (NGX_STREAM_UPSTREAM_ZONE)
int len;
const u_char *p;
ngx_stream_upstream_rr_peers_t *peers;
u_char buf[NGX_SSL_MAX_SESSION_SIZE];
#endif
peer = rrp->current;
#if (NGX_STREAM_UPSTREAM_ZONE)
peers = rrp->peers;
if (peers->shpool) {
ngx_stream_upstream_rr_peers_rlock(peers);
ngx_stream_upstream_rr_peer_lock(peers, peer);
if (peer->ssl_session == NULL) {
ngx_stream_upstream_rr_peer_unlock(peers, peer);
ngx_stream_upstream_rr_peers_unlock(peers);
return NGX_OK;
}
len = peer->ssl_session_len;
ngx_memcpy(buf, peer->ssl_session, len);
ngx_stream_upstream_rr_peer_unlock(peers, peer);
ngx_stream_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_STREAM, 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_STREAM, pc->log, 0,
"set session: %p", ssl_session);
return rc;
}
static void
ngx_stream_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc,
void *data)
{
ngx_stream_upstream_rr_peer_data_t *rrp = data;
ngx_ssl_session_t *old_ssl_session, *ssl_session;
ngx_stream_upstream_rr_peer_t *peer;
#if (NGX_STREAM_UPSTREAM_ZONE)
int len;
u_char *p;
ngx_stream_upstream_rr_peers_t *peers;
u_char buf[NGX_SSL_MAX_SESSION_SIZE];
#endif
#if (NGX_STREAM_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_STREAM, 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_stream_upstream_rr_peers_rlock(peers);
ngx_stream_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_stream_upstream_rr_peer_unlock(peers, peer);
ngx_stream_upstream_rr_peers_unlock(peers);
return;
}
peer->ssl_session_len = len;
}
ngx_memcpy(peer->ssl_session, buf, len);
ngx_stream_upstream_rr_peer_unlock(peers, peer);
ngx_stream_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_STREAM, 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_STREAM, pc->log, 0,
"old session: %p", old_ssl_session);
/* TODO: may block */
ngx_ssl_free_session(old_ssl_session);
}
}
static ngx_int_t
ngx_stream_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data)
{
return NGX_OK;
}
static void
ngx_stream_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data)
{
return;
}
#endif