Hi Paul - We're running a reasonably large site on MySQL. Approx 400GB of mail storage, with 100k users. Currently Dbmail 1.x; although likely to move to 2.0 when I get back from holiday.
Won't say it hasn't been without its challenges. We've tried both MyISAM and Innodb tables and due to either MySQL bugs or external glitches (power cut) had had the misfortune to need to check and repair our large database tables which has proven to be a nightmare. This isn't an issue with DBMAIL - more MySQL... Not sure if it's a really good choice for large installs, but I don't know Postgres well enough and it may or may not be any better. We tried 4.1.7 recently and in a master-slave scenario had some software crashes in MySQL, which caused some issues. I'd suggest waiting to 4.1.9 or 4.1.10 before using it; although the performance of 4.1 seems really good in comparison to 4.0. Of late we've just started using MERGE tables to help partition our data files up. So messageblks = UNION(messageblks_alpha, messageblks_beta, messageblks_charlie). This has worked fairly well (esp under 4.1), and ok under 4.0 -- and means that messageblks_alpha/beta effectivley become read-only except for when running the maintenance program to purge messages. I've found this a godsend as can then optimise the read-only tables on a slave and copy them back to the master, etc. It also means that your database tables can be kept at smaller sizes -- say 100Gb, which means checks/repairs/optimize are less of a burden; and more than likely a problem is likely only to affect the current 'insert' table => less data to have to check. All in all, Dbmail has been good -- provided you have a good database setup. We have separate servers for SMTP delivery and POP/IMAP; and separate DB server (and now a read-only slave for backups) - currently on Xeon 2.4G with 1TB SCSI array. Having the read-only slave is quite good; as you can do intensive queries without affecting users... Like 'show me all users with this text in their message'. I've even written custom maintenance programs which use the slave to lookup messages for purging, and just direct the DB writes to the master. This has avoided the table-lock issues that you get with MyISAM tables when doing big queries. Hope this info helps. Unfortunatley I'm on holiday from tomorrow morning for 6 weeks, so may not reply for a while if you've got any questions; although bound to be online every now and then while away. -- Regards, Mark Mackay -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Stewart Sent: Friday, 17 December 2004 2:28 a.m. To: [email protected] Subject: [Dbmail] Large Sites Hi there.. Just new to this mailing list but ran across dbmail recently at a client site... Looks pretty good..:) I'm wondering what sizes of "real-life" sites are running currently and what kind of hardware, how many users etc? Has anyone pushed the limits or is MySQL the limit in this system per say? Thanks for your time, Paul
