Thank you for your answer.
We actually could not wait for a solution or workaround anymore, due to
the project planning and
the time we spent trying to find a solution with OpenLDAP.
So, we decided to test replacing OpenLDAP by OpenDJ, and the tests give
pretty good results: we don't have the problem anymore.
Howard Chu a écrit :
> Full_Name: Cyril Grosjean
> Version: 2.4.26
> OS: Red Hat Enterprise Linux Server release 5.4 (Tikanga)
> URL: ftp://ftp.openldap.org/incoming/
> Submission from: (NULL) (18.104.22.168)
> My OpenLDAP server freezes, after a few requests, and I can't
> understand why.
> I have a few LDAP clients (ldapsearch, a custom Java app. and
> ApacheDirectoryStudio), running from different systems, either
> locally on the
> OpenLDAP server, or on another OpenLDAP server, or on a remote
> workstation, and
> none manages to get an answer from OpenLDAP. The connection is
> established but
> each client gets stuck waiting for any result.
> We can reproduce the freeze, after a few requests coming from the
> custom Java
> application. The problem doesn't occur if we don't use that application.
> The last time, it occured only a few minutes after the OpenLDAP
> daemon was
> restarted, under very low load.
> I use OpenLDAP 2.4.26, over Red Hat Enterprise Linux Server release 5.4
> (Tikanga), Kernel version 2.6.18-164.el5, amd64 architecture over
> I also use BDB 4.8.30, and OpenLDAP's been compiled with the
> following options:
> ./configure --prefix=/opt/openldap-2.4.26 --enable-dynamic=yes
> --enable-dynlist=yes --enable-memberof=yes --enable-ppolicy=yes
> --enable-accesslog=yes --enable-sssvlv=yes
> I noticed only 60 to 70 established connections on port 389
> (according to
> netstat) when the freeze occurs.
> The OpenLDAP server is set in syncrepl mirror mode replication, and
> the other
> OpenLDAP server (only used as a hot stand-by) works fine (but doesn't
> any load). However, one can reproduce the problem with replication
Looks like you have a thread blocked trying to modify a record, while
all the other writer threads are blocked waiting for that writer to
complete. The output of db_stat -CA would help to indicate why the
writer is blocked.
It also looks like you've configured your replication with mirrormode
and delta-syncrepl. This combination is not yet supported in OpenLDAP,
certainly not in 2.4.26. It may be supported in 2.4.27, depending on
how our ongoing testing turns out.