Mike Meredith wrote: > Hi > > I should point out that I'm allergic to using a database server hooked > into a live mail server, however ... >
ACK. Safest viewpoint. They can break. We also run ONLY via sockets though, never TCP, so that pushes us the other way, > > Sometime around Thu, 31 Aug 2006 22:58:04 +0800, it may be that W B > Hacker wrote: > >>You will, however, also find my name on other posts saying we *use* >>SQL DB-driven Exim, but do NOT recommend it to others. >> >>Also - depending on an RDBMS engine means one more thing that can go >>wrong, so overall the DB-driven system is more resource-intensive, >>and somewhat slower and less robust than flat files or a BDB, GDB, >>CDB environment. > > > Of course if you were to use an RDBMS engine as a back end, and Perl > (or your scripting language of choice) generating the CDB files then > you don't loose in having something else to go wrong. Providing of > course your script checks that things haven't blown up! PostgreSQL can 'trigger' on a change beng committed, output in the right format directly to the proper storage location from an SQL stored procedure. No need to deal with perl sin-tax. If I have to do externals, I'd go ahead and use embedded 'C' binaries. (though I do compile mine with Forth as well...) > > You do lose the facility of being able to change the Exim data live, > but that (as discussed previously) isn't vital in many/most cases. Live enough. The next child process spawned will get the most recent update. > > >>Extensive testing is a must, and best done on an R&D box. > > > True enough! > > Rolling your own solution based around a script does have an advantage > here in that you can migrate slowly ... some data being pulled from SQL > tables into CDB files, and other data being generated from text files. > Heck! When migrating from BDB to CDB files I even setup two routers so > that it would fallback to the BDB files if the CDB files were broken. Ah! Another 'belt and braces' guy! > > Rolling your own script to do this is tons of work of course, but it > may be safer and is more fun (I do have an unusual sense of fun). > > As an illustration of how a script can work, I've essentially used much > the same script for years to scrape mail addresses from a collection of > Mercury servers, added scraping from an LDAP directory, generated BDB > files initially and now generate CDB files. > ACK. Dunno if any of us have mentioned it, but having the RDBMS does bring along a massive collection of manipulation, verification, and statistical tools. Bill -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
