diff -Naur a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
--- a/src/http/ngx_http_upstream.c	2009-12-23 10:31:16.000000000 -0500
+++ b/src/http/ngx_http_upstream.c	2010-01-20 15:26:24.000000000 -0500
@@ -24,8 +24,6 @@
 static void ngx_http_upstream_wr_check_broken_connection(ngx_http_request_t *r);
 static void ngx_http_upstream_check_broken_connection(ngx_http_request_t *r,
     ngx_event_t *ev);
-static void ngx_http_upstream_connect(ngx_http_request_t *r,
-    ngx_http_upstream_t *u);
 static ngx_int_t ngx_http_upstream_reinit(ngx_http_request_t *r,
     ngx_http_upstream_t *u);
 static void ngx_http_upstream_send_request(ngx_http_request_t *r,
@@ -600,13 +598,12 @@
 
 found:
 
-    if (uscf->peer.init(r, uscf) != NGX_OK) {
-        ngx_http_upstream_finalize_request(r, u,
-                                           NGX_HTTP_INTERNAL_SERVER_ERROR);
-        return;
+    switch(uscf->peer.init(r, uscf)) {
+        case NGX_OK:   ngx_http_upstream_connect(r, u);
+        case NGX_BUSY: return;
     }
 
-    ngx_http_upstream_connect(r, u);
+    ngx_http_upstream_finalize_request(r, u, NGX_HTTP_INTERNAL_SERVER_ERROR);
 }
 
 
@@ -1030,7 +1027,7 @@
 }
 
 
-static void
+void
 ngx_http_upstream_connect(ngx_http_request_t *r, ngx_http_upstream_t *u)
 {
     ngx_int_t          rc;
diff -Naur a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
--- a/src/http/ngx_http_upstream.h	2009-12-23 09:22:17.000000000 -0500
+++ b/src/http/ngx_http_upstream.h	2010-01-20 15:24:36.000000000 -0500
@@ -321,6 +321,8 @@
 
 ngx_int_t ngx_http_upstream_create(ngx_http_request_t *r);
 void ngx_http_upstream_init(ngx_http_request_t *r);
+#define NGX_HTTP_UPSTREAM_INIT_BUSY_PATCH_VERSION  1
+void ngx_http_upstream_connect(ngx_http_request_t *r, ngx_http_upstream_t *u);
 ngx_http_upstream_srv_conf_t *ngx_http_upstream_add(ngx_conf_t *cf,
     ngx_url_t *u, ngx_uint_t flags);
 char *ngx_http_upstream_bind_set_slot(ngx_conf_t *cf, ngx_command_t *cmd,