Re: [Dovecot] MySQL as a storage only.?
Jack Stewart wrote: Neil wrote: On Tue, Dec 23, 2008 at 2:20 AM, Timo Sirainen wrote: On Dec 23, 2008, at 4:51 AM, R A wrote: Especially if you try to implement cloud-like services, where you have the possibility of links temporarily going down between servers, and mail can come in to any point, and be retrieved or moved at any point. You really need transactions then, to track every mails change in time, and to replicate those when you get connectivity back. You "can" possibly do it by tracking dovecot logs and do the replication yourself with scripts, but using a database would probably be easier here. I've also planned easy replication support for Dovecot. Also I don't think doing the SQL replication correctly and without losing any data on error conditions is as easy as you think. +1 Needless to say, replication would be _very_ useful... At least in 5, MySQL replication is very difficult. Based on my experience with amavisd, master <-> master replication does not work if you have foreign key constraints. master <-> slaves can have issues with high activity as a key on the master might get update while a search is happening on the slave (again this is with foreign key constraints). Then you'll probably need innodb for performance so backups become more challenging. Lastly, disk usage triples. Hate to be a wet blanket, but this is what I've seen. If you don't need the constraints, the problem becomes more manageable. Still your safest bet for replication at this time is to use the slave as a backup with some sort of auto promotion mechanism. The network master daemon (nmdb?) looks promising for straight forward databases. Don't forget blob sizing. I'm not sure how Oracle is for replication. Setups/configuration does not sound simple from the dba's I've talked to, although RACK looks decent. MySQL does work well for index problems (i.e. searches) where the index can be reconstructed if their is a failure and the searching process doesn't seize in a failure. Just my opinion and warning. I agree with you from my own experience - using a database in this manner is a huge kludge. maildir/dbox is far better suited for mail storage. For small installations where there is little mail storage and performance is not an issue, maybe. But I'd rather see Timo's time spent on an internal to dovecot master-slave and master-master system. ~Seth
Re: [Dovecot] MySQL as a storage only.?
Neil wrote: On Tue, Dec 23, 2008 at 2:20 AM, Timo Sirainen wrote: On Dec 23, 2008, at 4:51 AM, R A wrote: Especially if you try to implement cloud-like services, where you have the possibility of links temporarily going down between servers, and mail can come in to any point, and be retrieved or moved at any point. You really need transactions then, to track every mails change in time, and to replicate those when you get connectivity back. You "can" possibly do it by tracking dovecot logs and do the replication yourself with scripts, but using a database would probably be easier here. I've also planned easy replication support for Dovecot. Also I don't think doing the SQL replication correctly and without losing any data on error conditions is as easy as you think. +1 Needless to say, replication would be _very_ useful... At least in 5, MySQL replication is very difficult. Based on my experience with amavisd, master <-> master replication does not work if you have foreign key constraints. master <-> slaves can have issues with high activity as a key on the master might get update while a search is happening on the slave (again this is with foreign key constraints). Then you'll probably need innodb for performance so backups become more challenging. Lastly, disk usage triples. Hate to be a wet blanket, but this is what I've seen. If you don't need the constraints, the problem becomes more manageable. Still your safest bet for replication at this time is to use the slave as a backup with some sort of auto promotion mechanism. The network master daemon (nmdb?) looks promising for straight forward databases. Don't forget blob sizing. I'm not sure how Oracle is for replication. Setups/configuration does not sound simple from the dba's I've talked to, although RACK looks decent. MySQL does work well for index problems (i.e. searches) where the index can be reconstructed if their is a failure and the searching process doesn't seize in a failure. Just my opinion and warning. ---Jack
Re: [Dovecot] MySQL as a storage only.?
On Tue, Dec 23, 2008 at 2:20 AM, Timo Sirainen wrote: > On Dec 23, 2008, at 4:51 AM, R A wrote: >> Especially if you try >> to implement cloud-like services, where you have the possibility of >> links temporarily going down between servers, and mail can come in to >> any point, and be retrieved or moved at any point. >> >> You really need transactions then, to track every mails change in time, >> and to replicate those when you get connectivity back. You "can" >> possibly do it by tracking dovecot logs and do the replication yourself >> with scripts, but using a database would probably be easier here. > > I've also planned easy replication support for Dovecot. Also I don't think > doing the SQL replication correctly and without losing any data on error > conditions is as easy as you think. > +1 Needless to say, replication would be _very_ useful...
Re: [Dovecot] MySQL as a storage only.?
On Dec 23, 2008, at 4:51 AM, R A wrote: Romer Ventura wrote: Hello, I was wondering is I could use MySQL as storage only..? Meaning that no user information, other than the obvious email address associated with an specific email so that each email can be showed to the right user, will be stored in a MySQL database instead of /home/vmail/DOMAIN/ Would I get any advantages.? Would it be better, faster? Thanks I think IF it would be supported in a future version it would be a great addition. I did already start it once but didn't get it very well working. It's a very low priority for me to finish it. Maybe once everything else is done and I can't really think of anything better to do.. Of course anyone else is free to implement it. http://dovecot.org/list/dovecot/2007-November/026632.html Especially if you try to implement cloud-like services, where you have the possibility of links temporarily going down between servers, and mail can come in to any point, and be retrieved or moved at any point. You really need transactions then, to track every mails change in time, and to replicate those when you get connectivity back. You "can" possibly do it by tracking dovecot logs and do the replication yourself with scripts, but using a database would probably be easier here. I've also planned easy replication support for Dovecot. Also I don't think doing the SQL replication correctly and without losing any data on error conditions is as easy as you think.
Re: [Dovecot] MySQL as a storage only.?
Romer Ventura wrote: > Hello, > > I was wondering is I could use MySQL as storage only..? Meaning that no > user information, other than the obvious email address associated with an > specific email so that each email can be showed to the right user, will be > stored in a MySQL database instead of /home/vmail/DOMAIN/ > > Would I get any advantages.? Would it be better, faster? > > Thanks > > I think IF it would be supported in a future version it would be a great addition. Especially if you try to implement cloud-like services, where you have the possibility of links temporarily going down between servers, and mail can come in to any point, and be retrieved or moved at any point. You really need transactions then, to track every mails change in time, and to replicate those when you get connectivity back. You "can" possibly do it by tracking dovecot logs and do the replication yourself with scripts, but using a database would probably be easier here. Also I think it might be good if you use imap flags a lot, I see a definitive benefit if dovecot could use sql as an index storage anyway. For speed just as a plain storage, it would most likely be a bit slower... So, for some it might be better, for others it would not... -Roger
Re: [Dovecot] MySQL as a storage only.?
On Wed, Dec 10, 2008 at 02:24:05PM -0600, Romer Ventura wrote: > Hello, > > I was wondering is I could use MySQL as storage only..? Meaning that no > user information, other than the obvious email address associated with an > specific email so that each email can be showed to the right user, will be > stored in a MySQL database instead of /home/vmail/DOMAIN/ > > Would I get any advantages.? Would it be better, faster? You may want to have a look at dbmail for this: http://www.dbmail.org/ AFAIK it's currently not in scope for Dovecot. Geert
[Dovecot] MySQL as a storage only.?
Hello, I was wondering is I could use MySQL as storage only..? Meaning that no user information, other than the obvious email address associated with an specific email so that each email can be showed to the right user, will be stored in a MySQL database instead of /home/vmail/DOMAIN/ Would I get any advantages.? Would it be better, faster? Thanks
