Re: max mails per folder
Andrea Brancatelli <[email protected]> Mon, 09 Nov 2015 12:38:06 +0100
| Newsgroups | gmane.mail.imap.dbmail |
|---|---|
| Organization | Schema31 s.r.l. |
| Message-ID | <[email protected]> |
Well, obviously it the depends on the mail amount. We have about 1000 mailboxes with about 350GB of online mail. On spike hours we have a full recycle of the logs in about 10 minutes especially because of circular replication increasing the server activities. Restart after a crash takes more or less 2 minutes. --- Andrea Brancatelli Schema31 S.p.a. Responsabile IT ROMA - BO - FI - PA ITALY Tel: +39. 06.98.358.472 Cell: +39 331.2488468 Fax: +39. 055.71.880.466 Società del Gruppo SC31 ITALIA Il 2015-11-09 12:26 Jure Pečar ha scritto: > On Mon, 09 Nov 2015 10:54:48 +0100 > Andrea Brancatelli <[email protected]> wrote: > >> My blind shot is that it doesn't depend on dbmail itself, but to MySQL >> "filling up". >> >> Things probably get slow when either: >> >> * your controler cache gets filled and the controller starts writing >> for real to disk >> * your InnoDB log buffer gets full and the DB has to start committing >> pending transactions to the real IDB files. >> >> There is not much you can to for the first thing, but for the second one >> you can tweak the innodb_log_file_size and innodb_log_files_in_group. >> >> The purpose of those files is being written sequentially thus avoiding >> the bottleneck of the disk having to seek the inodes and the free inodes >> as the table grows. >> >> I suggest you to "watch" those file while the DB is appending the >> messages and see how fast they get filled, a complete roundabout implies >> a flush to the real tables. >> >> Just to give you a vague idea, on our system we have 6 * 512MB files. > > I don't think that's a smart thing to do. See > https://www.percona.com/blog/2008/11/21/how-to-calculate-a-good-innodb-log-file-size/ [1] > > We have about 2MB/min going into innodb logs and already have 2*256MB innodb log files, which should be plenty. > > What kind of append performance are you seeing on your setup? > > What is your crash recovery time with such large log files? > > Anyway IO is not the bottleneck, as our db server is capable more than 4GB/s (nvme is amazing). It must be something else... Links: ------ [1] https://www.percona.com/blog/2008/11/21/how-to-calculate-a-good-innodb-log-file-size/ _______________________________________________ DBmail mailing list [email protected] http://mailman.fastxs.nl/cgi-bin/mailman/listinfo/dbmail