# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1333402175 0
# Node ID 1db899642518526fde00d9a587e7f6783ec20fcc
# Parent  5c199fa3fe3eb6b93dddffd5ca8e499c24939110
Upstream: reject upstreams without normal servers.

Such upstreams cause CPU hog later in the code as number of peers isn't
expected to be 0.  Currently this may happen either if there are only backup
servers defined in an upstream block, or if server with ipv6 address used
in an upstream block.

diff --git a/src/http/ngx_http_upstream_round_robin.c b/src/http/ngx_http_upstream_round_robin.c
--- a/src/http/ngx_http_upstream_round_robin.c
+++ b/src/http/ngx_http_upstream_round_robin.c
@@ -49,6 +49,13 @@ ngx_http_upstream_init_round_robin(ngx_c
             n += 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_http_upstream_rr_peers_t)
                               + sizeof(ngx_http_upstream_rr_peer_t) * (n - 1));
         if (peers == NULL) {