On Wed, 28 May 1997, Philip Hazel wrote:
> On Wed, 28 May 1997, Pete Ashdown wrote:
>
> > It seems like almost once a week I need to remove the old databases to
> > start fresh again. The program "exim_tidydb" generates a segfault when
> > trying to access the database, and all queue mail is forever stuck.
>
> You are, I presume, using Berkeley DB version 1.x? That seems to be in
> use in all these corruption cases. Which operating system? Which
> compiler? We are using Berkeley DB on Solaris 2.5 on some of our busier
> mail systems and haven't had any problems at all, over months and
> months. Not sure which compiler was used to compile it. David?
There are two different versions of DB in common use: db 1.8.5 and db
1.8.6. db 1.8.5 has known bugs with hashed db's. See
http://www.bostic.com/db/db.185.html for info on getting db 1.8.6
...
> I am going to do some work on the database code fairly soon. I am
> contemplating using an entirely distinct file for locking, rather than
> trying to lock on the file(s) used by the db library, because I suspect
> that some of the trouble may be caused by updates happening to the files
> on open(), before Exim has a chance to lock anything. If it locks on a
> separate file before going anywhere near the real files, this shouldn't
> happen, and also the problems that some people have seen when a db
> library tries to do its own locking and this doesn't interwork with
> Exim's own locking should go away. It should then be easier to use Exim
> with gdbm. I'm also going to take a look at Berkeley db 2.0, which has
> been recently released.
db 2.0 has built in record locking capabilities. It is relativly
automatic. However, db 2.0 has some rather significant API changes, so
there is no way you can link db 2.0 with Exim, without significant changes
to Exim.
> Philip
>
> --
> Philip Hazel University Computing Service,
> ph10@??? New Museums Site, Cambridge CB2 3QG,
> P.Hazel@??? England. Phone: +44 1223 334714
>
>
>
Tom
