Re: (ITS#7113) broken read-only replica results in assertion failure and crash on master slapd process

[hyc@symas.com]

kacarstensen@csupomona.edu wrote:
> I've investigated this issue a little bit more since my initial bug
> report.

> I'm not sure if connection_write is supposed to validate that a stream
> is active before or after calling slapd_clr_write, but it seems like the
> assertion wouldn't be an issue if that validation were performed before
> calling slapd_clr_write. To test this thought, I rebuilt openldap 2.4.28
> with the following patch:
>
>    --- openldap-2.4.28/servers/slapd/connection.c    2011-11-25 10:52:29.000000000 -0800
>    +++ openldap-2.4.28-new/servers/slapd/connection.c    2012-01-12 13:35:45.000000000 -0800
>    @@ -1893,8 +1893,6 @@
>
>      assert( connections != NULL );
>
>    - slapd_clr_write( s, 0 );
>    -
>      c = connection_get( s );
>      if( c == NULL ) {
>          Debug( LDAP_DEBUG_ANY,
>    @@ -1903,6 +1901,8 @@
>          return -1;
>      }
>
>    + slapd_clr_write( s, 0 );
>    +
>     #ifdef HAVE_TLS
>      if ( c->c_is_tls&&  c->c_needs_tls_accept ) {
>          connection_return( c );
>
> and tried to reproduce the problem under the same circumstances as
> reported in my initial bug report. The master slapd tolerated the
> misconfigured replicas for 5 days without crashing; before, it would
> crash reliably within a half hour or so. I didn't notice any regressions
> due to the patch, though the master slapd wasn't exposed to a typical
> workload during the experiment.
>
> Any thoughts on this patch?

Sounds OK to me, committed to git master. Thanks.

-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/