Re: BDB recovery after power outage

[vadim tarassov <vadim.tarassov@swissonline.ch>]

Hmm, Frank!

You will hardly find software "ready to use" in this world as it is 
written even on my mug: "Nobody is perfect", although it is not the 
point. The point is that if you are taking such responsibility on you to 
maintain data, you have at least to think a bit about what will happen 
with your persistent storage (BDB, OpenLDAP, MQSeries queue manager, 
IMS, CICS, DB2, MySQL etc) as soon as you switch your electricity off. 
And if you thought this bit, the most natural idea which can get in your 
mind is to try to switch off electricity, see what had happened and to 
try to recover data if any went lost. It is also very natural to prepare 
yourself for recovering data for the case of disaster, and to start to 
look for documentation about doing it. And it is again very natural to 
look in FAQ on OpenLDAP site, and believe me, you will find an article 
"How to maintain Berkeley DB"

http://www.openldap.org/faq/data/cache/286.html

Also believe me it remains a matter of two clicks to come accross with 
db_recover.

BR, vadim tarassov.

Frank Swasey wrote:

> On Apr 20 at 6:45pm, Howard Chu wrote:
>
>  
>
> > In early versions of OpenLDAP 2.1 we had slapd automatically perform recovery
> > whenever it started. However, this caused problems if you accidentally
> > started a second slapd while one was running - the second recovery would wipe
> > out the environment that the first one was using. Since all of the locking
> > information is contained inside the BDB environment, there was no locking
> > mechanism to prevent this occurrence. So now we no longer do automatic
> > recovery; it's up to you to run db_recover by hand or add it to your server
> > startup scripts as needed.
> >    
>
> Howard,
>  The fact that the openldap administrator is required to run db_recover
> manually after a crash of the BDB backend is NOT documented in the
> openldap manual pages nor the "OpenLDAP 2.1 Administrator's Guide".  In 
> fact, "db_recover" is NEVER even used in the man pages or the 
> Administrator's Guide.
>
>  Thank you, I now have a clearer understanding of why I think the BDB
> Backend is, in my personal opinion, not ready for real use.
>  
>  Constructive comments on why such a critical fact would be entirely
> missing from the openldap documentation are welcomed.  Flames and
> insults will be silently ignored.
>
>