Re: (ITS#8146) Slapd with mdb consumes 100% CPU if deref aliases is requested

[hyc@symas.com]

andrew.findlay@skills-1st.co.uk wrote:
> Full_Name: Andrew Findlay
> Version: 2.4.40
> OS: Linux: OpenSuSE 13.2
> URL: ftp://ftp.openldap.org/incoming/openldap-mdb-spin-bug.tgz
> Submission from: (NULL) (2001:8b0:8d0:f7e1:61a6:169e:b4ba:9954)
>
>
> Some client programs (such as Apache Directory Studio) request alias
> dereferencing by default. This puts slapd with mdb into a spin where it consumes
> 100% of a CPU. Other threads continue to work and new connections are accepted.
> Timeouts do not terminate the spin. Disconnecting the client does not terminate
> the spin.

Already fixed in RE24.

> To reproduce: start slapd and issue a search of the form:
>
> ldapsearch -a search -x -b dc=example,dc=org objectclass=person
>
> I have placed a tarball on the FTP server containing:
>
> slapd.conf
> sample data in LDIF
> gdb output showing thread trace after breaking in
> script of client commands
>
> The build options were:
>
> CFLAGS=-g
> export CFLAGS
>
> ./configure     --prefix=/meme/andrew/test/openldap-2.4.40 \
>                  --enable-spasswd \
>                  --enable-crypt \
>                  --enable-slapi \
>                  --enable-overlays \
>                  --enable-hdb=no \
>                  --enable-bdb=no \
>                  --enable-ldap \
>                  --enable-rewrite \
>                  --enable-meta \
>                  --enable-null \
>                  --enable-monitor \
>                  --enable-relay \
>                  --enable-sock \
>                  --with-cyrus-sasl \
>                  --with-tls
>
>
> For those that need it, the workaround with Apache Directory Studio is to
> disable alias dereferencing in the Browser Options tab for the connection.
>
> Andrew
>
>


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