# HG changeset patch
# User Roman Arutyunyan <arut@nginx.com>
# Date 1410533447 -14400
# Node ID d09b689911ac2a3236f0fea322088e586814f9f8
# Parent  575175ebf4b40419e634eac9c5fcd41f0ffa1727
Upstream: limited next_upstream time and tries (ticket #544).

The new directives {proxy,fastcgi,scgi,uwsgi,memcached}_next_upstream_tries
and {proxy,fastcgi,scgi,uwsgi,memcached}_next_upstream_timeout limit
the number of upstreams tried and the maximum time spent for these tries
when searching for a valid upstream.

diff --git a/src/event/ngx_event_connect.h b/src/event/ngx_event_connect.h
--- a/src/event/ngx_event_connect.h
+++ b/src/event/ngx_event_connect.h
@@ -42,6 +42,7 @@ struct ngx_peer_connection_s {
     ngx_str_t                       *name;
 
     ngx_uint_t                       tries;
+    ngx_msec_t                       start_time;
 
     ngx_event_get_peer_pt            get;
     ngx_event_free_peer_pt           free;
diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -442,6 +442,20 @@ static ngx_command_t  ngx_http_fastcgi_c
       offsetof(ngx_http_fastcgi_loc_conf_t, upstream.next_upstream),
       &ngx_http_fastcgi_next_upstream_masks },
 
+    { ngx_string("fastcgi_next_upstream_tries"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_num_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_fastcgi_loc_conf_t, upstream.next_upstream_tries),
+      NULL },
+
+    { ngx_string("fastcgi_next_upstream_timeout"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_msec_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_fastcgi_loc_conf_t, upstream.next_upstream_timeout),
+      NULL },
+
     { ngx_string("fastcgi_param"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE23,
       ngx_http_upstream_param_set_slot,
@@ -2314,6 +2328,7 @@ ngx_http_fastcgi_create_loc_conf(ngx_con
 
     conf->upstream.store = NGX_CONF_UNSET;
     conf->upstream.store_access = NGX_CONF_UNSET_UINT;
+    conf->upstream.next_upstream_tries = NGX_CONF_UNSET_UINT;
     conf->upstream.buffering = NGX_CONF_UNSET;
     conf->upstream.ignore_client_abort = NGX_CONF_UNSET;
 
@@ -2322,6 +2337,7 @@ ngx_http_fastcgi_create_loc_conf(ngx_con
     conf->upstream.connect_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.send_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.read_timeout = NGX_CONF_UNSET_MSEC;
+    conf->upstream.next_upstream_timeout = NGX_CONF_UNSET_MSEC;
 
     conf->upstream.send_lowat = NGX_CONF_UNSET_SIZE;
     conf->upstream.buffer_size = NGX_CONF_UNSET_SIZE;
@@ -2387,6 +2403,9 @@ ngx_http_fastcgi_merge_loc_conf(ngx_conf
     ngx_conf_merge_uint_value(conf->upstream.store_access,
                               prev->upstream.store_access, 0600);
 
+    ngx_conf_merge_uint_value(conf->upstream.next_upstream_tries,
+                              prev->upstream.next_upstream_tries, 0);
+
     ngx_conf_merge_value(conf->upstream.buffering,
                               prev->upstream.buffering, 1);
 
@@ -2405,6 +2424,9 @@ ngx_http_fastcgi_merge_loc_conf(ngx_conf
     ngx_conf_merge_msec_value(conf->upstream.read_timeout,
                               prev->upstream.read_timeout, 60000);
 
+    ngx_conf_merge_msec_value(conf->upstream.next_upstream_timeout,
+                              prev->upstream.next_upstream_timeout, 0);
+
     ngx_conf_merge_size_value(conf->upstream.send_lowat,
                               prev->upstream.send_lowat, 0);
 
diff --git a/src/http/modules/ngx_http_memcached_module.c b/src/http/modules/ngx_http_memcached_module.c
--- a/src/http/modules/ngx_http_memcached_module.c
+++ b/src/http/modules/ngx_http_memcached_module.c
@@ -102,6 +102,20 @@ static ngx_command_t  ngx_http_memcached
       offsetof(ngx_http_memcached_loc_conf_t, upstream.next_upstream),
       &ngx_http_memcached_next_upstream_masks },
 
+    { ngx_string("memcached_next_upstream_tries"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_num_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_memcached_loc_conf_t, upstream.next_upstream_tries),
+      NULL },
+
+    { ngx_string("memcached_next_upstream_timeout"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_msec_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_memcached_loc_conf_t, upstream.next_upstream_timeout),
+      NULL },
+
     { ngx_string("memcached_gzip_flag"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
       ngx_conf_set_num_slot,
@@ -583,9 +597,11 @@ ngx_http_memcached_create_loc_conf(ngx_c
      */
 
     conf->upstream.local = NGX_CONF_UNSET_PTR;
+    conf->upstream.next_upstream_tries = NGX_CONF_UNSET_UINT;
     conf->upstream.connect_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.send_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.read_timeout = NGX_CONF_UNSET_MSEC;
+    conf->upstream.next_upstream_timeout = NGX_CONF_UNSET_MSEC;
 
     conf->upstream.buffer_size = NGX_CONF_UNSET_SIZE;
 
@@ -619,6 +635,9 @@ ngx_http_memcached_merge_loc_conf(ngx_co
     ngx_conf_merge_ptr_value(conf->upstream.local,
                               prev->upstream.local, NULL);
 
+    ngx_conf_merge_uint_value(conf->upstream.next_upstream_tries,
+                              prev->upstream.next_upstream_tries, 0);
+
     ngx_conf_merge_msec_value(conf->upstream.connect_timeout,
                               prev->upstream.connect_timeout, 60000);
 
@@ -628,6 +647,9 @@ ngx_http_memcached_merge_loc_conf(ngx_co
     ngx_conf_merge_msec_value(conf->upstream.read_timeout,
                               prev->upstream.read_timeout, 60000);
 
+    ngx_conf_merge_msec_value(conf->upstream.next_upstream_timeout,
+                              prev->upstream.next_upstream_timeout, 0);
+
     ngx_conf_merge_size_value(conf->upstream.buffer_size,
                               prev->upstream.buffer_size,
                               (size_t) ngx_pagesize);
diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -505,6 +505,20 @@ static ngx_command_t  ngx_http_proxy_com
       offsetof(ngx_http_proxy_loc_conf_t, upstream.next_upstream),
       &ngx_http_proxy_next_upstream_masks },
 
+    { ngx_string("proxy_next_upstream_tries"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_num_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_proxy_loc_conf_t, upstream.next_upstream_tries),
+      NULL },
+
+    { ngx_string("proxy_next_upstream_timeout"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_msec_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_proxy_loc_conf_t, upstream.next_upstream_timeout),
+      NULL },
+
     { ngx_string("proxy_pass_header"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
       ngx_conf_set_str_array_slot,
@@ -2455,6 +2469,7 @@ ngx_http_proxy_create_loc_conf(ngx_conf_
 
     conf->upstream.store = NGX_CONF_UNSET;
     conf->upstream.store_access = NGX_CONF_UNSET_UINT;
+    conf->upstream.next_upstream_tries = NGX_CONF_UNSET_UINT;
     conf->upstream.buffering = NGX_CONF_UNSET;
     conf->upstream.ignore_client_abort = NGX_CONF_UNSET;
 
@@ -2463,6 +2478,7 @@ ngx_http_proxy_create_loc_conf(ngx_conf_
     conf->upstream.connect_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.send_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.read_timeout = NGX_CONF_UNSET_MSEC;
+    conf->upstream.next_upstream_timeout = NGX_CONF_UNSET_MSEC;
 
     conf->upstream.send_lowat = NGX_CONF_UNSET_SIZE;
     conf->upstream.buffer_size = NGX_CONF_UNSET_SIZE;
@@ -2543,6 +2559,9 @@ ngx_http_proxy_merge_loc_conf(ngx_conf_t
     ngx_conf_merge_uint_value(conf->upstream.store_access,
                               prev->upstream.store_access, 0600);
 
+    ngx_conf_merge_uint_value(conf->upstream.next_upstream_tries,
+                              prev->upstream.next_upstream_tries, 0);
+
     ngx_conf_merge_value(conf->upstream.buffering,
                               prev->upstream.buffering, 1);
 
@@ -2561,6 +2580,9 @@ ngx_http_proxy_merge_loc_conf(ngx_conf_t
     ngx_conf_merge_msec_value(conf->upstream.read_timeout,
                               prev->upstream.read_timeout, 60000);
 
+    ngx_conf_merge_msec_value(conf->upstream.next_upstream_timeout,
+                              prev->upstream.next_upstream_timeout, 0);
+
     ngx_conf_merge_size_value(conf->upstream.send_lowat,
                               prev->upstream.send_lowat, 0);
 
diff --git a/src/http/modules/ngx_http_scgi_module.c b/src/http/modules/ngx_http_scgi_module.c
--- a/src/http/modules/ngx_http_scgi_module.c
+++ b/src/http/modules/ngx_http_scgi_module.c
@@ -299,6 +299,20 @@ static ngx_command_t ngx_http_scgi_comma
       offsetof(ngx_http_scgi_loc_conf_t, upstream.next_upstream),
       &ngx_http_scgi_next_upstream_masks },
 
+    { ngx_string("scgi_next_upstream_tries"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_num_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_scgi_loc_conf_t, upstream.next_upstream_tries),
+      NULL },
+
+    { ngx_string("scgi_next_upstream_timeout"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_msec_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_scgi_loc_conf_t, upstream.next_upstream_timeout),
+      NULL },
+
     { ngx_string("scgi_param"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE23,
       ngx_http_upstream_param_set_slot,
@@ -1074,6 +1088,7 @@ ngx_http_scgi_create_loc_conf(ngx_conf_t
 
     conf->upstream.store = NGX_CONF_UNSET;
     conf->upstream.store_access = NGX_CONF_UNSET_UINT;
+    conf->upstream.next_upstream_tries = NGX_CONF_UNSET_UINT;
     conf->upstream.buffering = NGX_CONF_UNSET;
     conf->upstream.ignore_client_abort = NGX_CONF_UNSET;
 
@@ -1082,6 +1097,7 @@ ngx_http_scgi_create_loc_conf(ngx_conf_t
     conf->upstream.connect_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.send_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.read_timeout = NGX_CONF_UNSET_MSEC;
+    conf->upstream.next_upstream_timeout = NGX_CONF_UNSET_MSEC;
 
     conf->upstream.send_lowat = NGX_CONF_UNSET_SIZE;
     conf->upstream.buffer_size = NGX_CONF_UNSET_SIZE;
@@ -1142,6 +1158,9 @@ ngx_http_scgi_merge_loc_conf(ngx_conf_t 
     ngx_conf_merge_uint_value(conf->upstream.store_access,
                               prev->upstream.store_access, 0600);
 
+    ngx_conf_merge_uint_value(conf->upstream.next_upstream_tries,
+                              prev->upstream.next_upstream_tries, 0);
+
     ngx_conf_merge_value(conf->upstream.buffering,
                               prev->upstream.buffering, 1);
 
@@ -1160,6 +1179,9 @@ ngx_http_scgi_merge_loc_conf(ngx_conf_t 
     ngx_conf_merge_msec_value(conf->upstream.read_timeout,
                               prev->upstream.read_timeout, 60000);
 
+    ngx_conf_merge_msec_value(conf->upstream.next_upstream_timeout,
+                              prev->upstream.next_upstream_timeout, 0);
+
     ngx_conf_merge_size_value(conf->upstream.send_lowat,
                               prev->upstream.send_lowat, 0);
 
diff --git a/src/http/modules/ngx_http_uwsgi_module.c b/src/http/modules/ngx_http_uwsgi_module.c
--- a/src/http/modules/ngx_http_uwsgi_module.c
+++ b/src/http/modules/ngx_http_uwsgi_module.c
@@ -354,6 +354,20 @@ static ngx_command_t ngx_http_uwsgi_comm
       offsetof(ngx_http_uwsgi_loc_conf_t, upstream.next_upstream),
       &ngx_http_uwsgi_next_upstream_masks },
 
+    { ngx_string("uwsgi_next_upstream_tries"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_num_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_uwsgi_loc_conf_t, upstream.next_upstream_tries),
+      NULL },
+
+    { ngx_string("uwsgi_next_upstream_timeout"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_msec_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_uwsgi_loc_conf_t, upstream.next_upstream_timeout),
+      NULL },
+
     { ngx_string("uwsgi_param"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE23,
       ngx_http_upstream_param_set_slot,
@@ -1254,6 +1268,7 @@ ngx_http_uwsgi_create_loc_conf(ngx_conf_
 
     conf->upstream.store = NGX_CONF_UNSET;
     conf->upstream.store_access = NGX_CONF_UNSET_UINT;
+    conf->upstream.next_upstream_tries = NGX_CONF_UNSET_UINT;
     conf->upstream.buffering = NGX_CONF_UNSET;
     conf->upstream.ignore_client_abort = NGX_CONF_UNSET;
 
@@ -1262,6 +1277,7 @@ ngx_http_uwsgi_create_loc_conf(ngx_conf_
     conf->upstream.connect_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.send_timeout = NGX_CONF_UNSET_MSEC;
     conf->upstream.read_timeout = NGX_CONF_UNSET_MSEC;
+    conf->upstream.next_upstream_timeout = NGX_CONF_UNSET_MSEC;
 
     conf->upstream.send_lowat = NGX_CONF_UNSET_SIZE;
     conf->upstream.buffer_size = NGX_CONF_UNSET_SIZE;
@@ -1329,6 +1345,9 @@ ngx_http_uwsgi_merge_loc_conf(ngx_conf_t
     ngx_conf_merge_uint_value(conf->upstream.store_access,
                               prev->upstream.store_access, 0600);
 
+    ngx_conf_merge_uint_value(conf->upstream.next_upstream_tries,
+                              prev->upstream.next_upstream_tries, 0);
+
     ngx_conf_merge_value(conf->upstream.buffering,
                               prev->upstream.buffering, 1);
 
@@ -1347,6 +1366,9 @@ ngx_http_uwsgi_merge_loc_conf(ngx_conf_t
     ngx_conf_merge_msec_value(conf->upstream.read_timeout,
                               prev->upstream.read_timeout, 60000);
 
+    ngx_conf_merge_msec_value(conf->upstream.next_upstream_timeout,
+                              prev->upstream.next_upstream_timeout, 0);
+
     ngx_conf_merge_size_value(conf->upstream.send_lowat,
                               prev->upstream.send_lowat, 0);
 
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -698,6 +698,14 @@ found:
         return;
     }
 
+    u->peer.start_time = ngx_current_msec;
+
+    if (u->conf->next_upstream_tries
+        && u->peer.tries > u->conf->next_upstream_tries)
+    {
+        u->peer.tries = u->conf->next_upstream_tries;
+    }
+
     ngx_http_upstream_connect(r, u);
 }
 
@@ -3421,6 +3429,7 @@ static void
 ngx_http_upstream_next(ngx_http_request_t *r, ngx_http_upstream_t *u,
     ngx_uint_t ft_type)
 {
+    ngx_msec_t  timeout;
     ngx_uint_t  status, state;
 
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
@@ -3490,9 +3499,12 @@ ngx_http_upstream_next(ngx_http_request_
 
     if (status) {
         u->state->status = status;
-
-        if (u->peer.tries == 0 || !(u->conf->next_upstream & ft_type)) {
-
+        timeout = u->conf->next_upstream_timeout;
+
+        if (u->peer.tries == 0
+            || !(u->conf->next_upstream & ft_type)
+            || (timeout && ngx_current_msec - u->peer.start_time >= timeout))
+        {
 #if (NGX_HTTP_CACHE)
 
             if (u->cache_status == NGX_HTTP_CACHE_EXPIRED
diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -136,6 +136,7 @@ typedef struct {
     ngx_msec_t                       send_timeout;
     ngx_msec_t                       read_timeout;
     ngx_msec_t                       timeout;
+    ngx_msec_t                       next_upstream_timeout;
 
     size_t                           send_lowat;
     size_t                           buffer_size;
@@ -153,6 +154,7 @@ typedef struct {
     ngx_uint_t                       ignore_headers;
     ngx_uint_t                       next_upstream;
     ngx_uint_t                       store_access;
+    ngx_uint_t                       next_upstream_tries;
     ngx_flag_t                       buffering;
     ngx_flag_t                       pass_request_headers;
     ngx_flag_t                       pass_request_body;