directory-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Howard Chu <>
Subject Re: Usage of JDBM : Experience feedbacks
Date Tue, 28 Oct 2008 14:35:38 GMT
Robert Mertens wrote:
> Hi Florent,
> I am using the JDBM as a part of the Apache Directory Server. I am
> switching from OpenLDAP because it's Berkeley did not always shut down
> properly.

I find that quite difficult to believe. On a properly configured installation 
we never see corruption or data loss. We've even tested on machines that 
crashed due to failing DRAMs and the database (containing over 1 terabyte of 
data) still recovered in under 2 minutes on the subsequent reboot (after 
replacement of bad memory).

Ever since BerkeleyDB 4.2 came out, we've had no data corruption issues with 

> The JDBM seems to do the job, but does not seemt to handle
> emergency shutdowns very well(or is it the Apache Directory Server?).
> The BTree was corrupted when shutting down the machine it is running on
> when we, at the same time, performed actions against the Directory
> Server where we deleted entries. The result was that the Directory
> Server could not be restarted again without replacing the JDBM. I am
> waiting for Apache Directory Server team to implement a failover model
> for such occasions.
> Best Regards
> Robert Mertens
> +46(0)702-793778
> ------------------------------------------------------------------------
> *From:* Florent Gratta []
> *Sent:* Wednesday, October 22, 2008 11:20 AM
> *To:*
> *Subject:* Usage of JDBM : Experience feedbacks
> Hi All,
> I am currently Project Lead at Sicap, a Swiss company which designs
> softwares for mobile operators and the mobile network world in general.
> We are going to use a BTree library to index entries of csv files. We
> have identified JDBM library ( and we have
> seen that you are currently using it in Apache Directory.
> As there is no more tracker activity on this project and it seems that
> it is the same thing for support, we would like to know if JDBM is stable:
> è Have you encountered problems when you use this library in
> multithreaded mode: Several concurrent inserts at a time?
> è What is the behaviour of the library when we shut down with emergency?
> Is it robust? By this way, does BTree file could be corrupted?
> è Do you encountered performance lack in some cases?
> è Is there some limitations or lacks: Size of the index chain, cache
> size etc ...
> è Etc ...
> We are very interested on your feedbacks and experiences on JDBM library
> usage ?

   -- Howard Chu
   CTO, Symas Corp. 
   Director, Highland Sun
   Chief Architect, OpenLDAP

View raw message