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Re: BDB, endian
Howard,
I would be very much in favor of such a change. The main problem I'm having at
the moment in having to maintain LDAP servers on multiple platforms are that
the databases are not portable across platforms. The issues are:
1. The ID's do not have a fixed, platform-independent, data-type associated
with them, i.e. on 32-bit platforms the ID's are 32-bit integer values and
on 64-bit platforms the ID's are 64-bit integer values.
2. The ID's do not have a fixed, platform-independent, representation format
associated with them when they are stored in the database, i.e.
byte-orders differ between little-endian machines and big-endian
machines.
These 2 issues prevent me from being able to just copy the databases across to
the different platforms whenever a database corruption occurs, or I need to
resync the database contents with an other database. The method I have to use
now (running a slapcat on the source machine and a slapadd on the destination
machine) takes way too long for the multi-million entries LDAP directory I'm
maintaining.
I would be very pleased if these issues could be resolved. I guess your
suggestion already takes care of issue 2, but I would be very happy if we
could fix issue 1 while we are at it.
By the way, we should do this for both the bdb backend as the ldbm backend.
Just my $0.02.
Best regards,
Gertjan.
On Tuesday 18 November 2003 21:19, Howard Chu wrote:
> back-bdb currently uses custom sort functions with its Btree databases
> because otherwise the integer entry IDs don't sort correctly on
> little-endian (e.g. Intel) systems. The use of custom sort functions means
> it's unsafe to use SleepyCat's db_dump/db_load to backup/restore databases
> on little-endian machines.
>
> An alternative is to byteswap all of the entry IDs when they go to/from the
> database. I think this may impose a slight performance cost, but it would
> make the generic tools safe for use. Any thoughts on whether to make this
> change?
>
> -- Howard Chu
> Chief Architect, Symas Corp. Director, Highland Sun
> http://www.symas.com http://highlandsun.com/hyc
> Symas: Premier OpenSource Development and Support