Re: worker process exited on signal 11 (core dumped)

[Igor Sysoev <igor@xxxxxxxxx>]

On Tue, Feb 16, 2010 at 02:54:29PM +0300, Maxim Dounin wrote:

> Hello!
> 
> On Wed, Feb 10, 2010 at 09:42:47PM +0300, Vladimir Sopot wrote:
> 
> > 
> > On Feb 10, 2010, at 3:49 PM, Maxim Dounin wrote:
> > 
> > >>> Ok, кажется я понял проблему.  Судя по всему memcached_pass не 
> > >>> дожидается полного прилёта trailer'а ("END") и ругается.  А в 
> > >>> случае keepalive остатки trailer'а долетают в ответ на следующий 
> > >>> запрос.
> > >>> 
> > >>> По идее строка "invalid trailer" должна наблюдаться и без 
> > >>> keepalive (но скорее всего реже), а "invalid response" - только 
> > >>> если keepalive включён.
> > >> 
> > >> 50 минут - полет нормальный, 
> > >> 
> > >> # grep -c 'subrequests cycle while processing' error.log
> > >> 22076
> > >> # grep memcached error.log
> > >> #
> > > 
> > > Видимо "реже" в данном случае вырождается в "почти никогда".
> > 
> > Однако, все же "почти" никогда:
> > 
> > # sed -n "1 p" error.log 
> > 2010/02/10 16:08:53 [error] 14875#0: *282680 directory index of "/wwwroot/" 
> > is forbidden
> > # grep memcached error.log
> > 2010/02/10 19:13:00 [error] 7643#0: *9676423 memcached sent invalid trailer 
> > while sending to client
> > 2010/02/10 19:40:46 [error] 7638#0: *11190967 memcached sent invalid 
> > trailer while sending to client
> > 2010/02/10 19:44:17 [error] 7641#0: *11386082 memcached sent invalid 
> > trailer while sending to client
> > 2010/02/10 19:50:40 [error] 7646#0: *11737608 memcached sent invalid 
> > trailer while sending to client
> > 2010/02/10 20:31:27 [error] 14006#0: *13901259 memcached sent invalid 
> > trailer while sending to client
> > 2010/02/10 21:28:42 [error] 20249#0: *16943253 memcached sent invalid 
> > trailer while sending to client
> 
> Патч.
> 
> Maxim Dounin

> # HG changeset patch
> # User Maxim Dounin <mdounin@xxxxxxxxxx>
> # Date 1266320928 -10800
> # Node ID 9009f1982e02d6f0614d4ddeae0672042442775a
> # Parent  09972a4975970f7c3510177b8a287283d3a53c58
> Memcached: correctly handle trailer split into several packets.
> 
> With old code message "[error] ... memcached sent invalid trailer" may appear
> in logs for no reason.  It doesn't cause any harm except message itself
> with official nginx though may cause spurious errors on connection reuse with
> upstream keepalive module.
> 
> 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
> @@ -432,15 +432,20 @@ ngx_http_memcached_filter(void *data, ss
>  
>          if (ngx_strncmp(b->last,
>                     ngx_http_memcached_end + NGX_HTTP_MEMCACHED_END - 
> ctx->rest,
> -                   ctx->rest)
> +                   bytes)
>              != 0)
>          {
>              ngx_log_error(NGX_LOG_ERR, ctx->request->connection->log, 0,
>                            "memcached sent invalid trailer");
> +
> +            u->length = 0;
> +            ctx->rest = 0;
> +
> +            return NGX_OK;
>          }
>  
> -        u->length = 0;
> -        ctx->rest = 0;
> +        u->length -= bytes;
> +        ctx->rest -= bytes;
>  
>          return NGX_OK;
>      }

Макс, до 0.6.14 был практический такой же код, который ты привёл.
Commit message: "fix memcached END test"


-- 
Игорь Сысоев
http://sysoev.ru

Index: src/http/modules/ngx_http_memcached_module.c
===================================================================
--- src/http/modules/ngx_http_memcached_module.c        (revision 873)
+++ src/http/modules/ngx_http_memcached_module.c        (revision 874)
@@ -426,15 +426,15 @@
 
         if (ngx_strncmp(b->last,
                    ngx_http_memcached_end + NGX_HTTP_MEMCACHED_END - ctx->rest,
-                   bytes)
+                   ctx->rest)
             != 0)
         {
             ngx_log_error(NGX_LOG_ERR, ctx->request->connection->log, 0,
                           "memcached sent invalid trailer");
         }
 
-        u->length -= bytes;
-        ctx->rest -= bytes;
+        u->length = 0;
+        ctx->rest = 0;
 
         return NGX_OK;
     }
@@ -453,7 +453,8 @@
 
     *ll = cl;
 
-    cl->buf->pos = b->last;
+    last = b->last;
+    cl->buf->pos = last;
     b->last += bytes;
     cl->buf->last = b->last;
 
@@ -461,20 +462,19 @@
                    "memcached filter bytes:%z size:%z length:%z rest:%z",
                    bytes, b->last - b->pos, u->length, ctx->rest);
 
-    if (b->last - b->pos <= (ssize_t) (u->length - NGX_HTTP_MEMCACHED_END)) {
+    if (bytes <= (ssize_t) (u->length - NGX_HTTP_MEMCACHED_END)) {
         u->length -= bytes;
         return NGX_OK;
     }
 
+    last += u->length - NGX_HTTP_MEMCACHED_END;
 
-    last = b->pos + u->length - NGX_HTTP_MEMCACHED_END;
-
     if (ngx_strncmp(last, ngx_http_memcached_end, b->last - last) != 0) {
         ngx_log_error(NGX_LOG_ERR, ctx->request->connection->log, 0,
                       "memcached sent invalid trailer");
     }
 
-    ctx->rest = u->length - (b->last - b->pos);
+    ctx->rest -= b->last - last;
     b->last = last;
     cl->buf->last = last;
     u->length = ctx->rest;

_______________________________________________
nginx-ru mailing list
nginx-ru@xxxxxxxxx
http://nginx.org/mailman/listinfo/nginx-ru