Re: I can't delete a shell DB

[Diego Woitasen <diego@woitasen.com.ar>]

On Wed, Apr 17, 2013 at 6:08 PM, Michael Ströder <michael@stroeder.com> wrote:
> Howard Chu wrote:
>> Michael Ströder wrote:
>>>>  From a practical standpoint - behavior of the service when clients are making
>>>> requests to a backend that gets removed is totally undefined.
>>>
>>> LDAP clients do not care about (OpenLDAP) database backends at all.
>>> They simply query a DIT.
>>
>> Yes, but they expect to get consistent answers to their queries. You cannot
>> make any assertions about consistency when the rug is pulled out from under a
>> running query.
>>
>>> AFAICS the original poster wanted to replace back-shell with back-sock for the
>>> very same naming context. In theory this could be done with back-config - only
>>> requring a very small downtime - entry deletion in back-config would be
>>> possible.
>>
>> It would require adding a suffix to one backend while removing it from
>> another. Since this can't be done in a single LDAP request it would require
>> wrapping both changes in a single LDAP Transaction.
>>
>> Doing it non-atomically would invariably result in inexplicable client error
>> messages as they send requests to an LDAP server that was "working fine
>> before" but suddenly replies "no global superior knowledge".
>
> Of course one would prevent clients from connecting before.
> That's what I meant with "requiring a very small downtime".
>
> Well, the point is that deleting something in back-config has to be done with
> some care - just like other non-trivial configuration/schema/data changes -
> but should not be completely impossible.
>
> Ciao, Michael.
>
>

My personal experience was: I had a requirement about having a custom
behavior for a subtree so I used back-shell because it looks the
easier option. It worked in a testing server and when I moved the
config to the production server it started to hangs (load wasn't very
high) frequently. Then I switched to back-sock recommend by somebody
at the IRC channel. It's been working very stable since the switch,
but back-shell remains there. I disabled it removing the subtree attrs
and others, but removing taking dependencies into consideration is a
good feature. Thinking that configurations only grows is out of the
real world.

I know that I could remove it from the filesystem, but I wouldn't.

Regards,
  Diego

--
Diego Woitasen