RE: (ITS#8609) segfault in mods.c - modify_add_values

[quanah@symas.com]

--On Thursday, April 20, 2017 9:02 PM +0000 henson@acm.org wrote:

>> From: Quanah Gibson-Mount
>> Sent: Thursday, April 20, 2017 8:07 AM
>>
>> You stated previously that you are in 4-way MMR.  It's not valid to have
>> a serverID of 0 in an MMR environment (See
>> <http://www.openldap.org/its/index.cgi/?findid=8635>).
>
> Well now, that's quite a fresh ITS 8-/. I'm guessing quite a few people
> have serverID's of 0 in their replicated environments, as I don't know
> that I've ever seen that information before. What are the ramifications
> of having a server with an ID of 0 in a replicated environment? What is
> the procedure for remediating the issue? Is it as simple as shutting down
> that server, updating the configuration to have a serverID of 4 and
> restarting it? Or does the database need to be stripped of all CSN's
> which have an ID of 0 via slapcat, grep -v, and then slapadd with the -w
> option on the master and then reloading from ldif on all the replicas?

It's fine for there to be legacy entryCSNs and a contextCSN for serverID of 
0.  However, it is not fine for any master in an MMR setup to have a 
specific serverID of 0.  If you're running with serverID's 0-3, I'd simply 
try an ldapmodify on the server with 0 to set its serverID to 4, and then 
do a modification against it, so it generates a new contextCSN that gets 
pushed out to all nodes.

--Quanah


--

Quanah Gibson-Mount
Product Architect
Symas Corporation
Packaged, certified, and supported LDAP solutions powered by OpenLDAP:
<http://www.symas.com>