Jake Anderson wrote:
Definitely. We need an algorithm that will prevent collisions at all cost. Such checksums will only be calculated during insertion to ensure uniqueness of the attachment so they will not affect the retrieval processes (pop/imap).
Just a thought on the mechanism for this, Might it be an idea to do it as part of the utils.
For conversion of an existing mail-store, yes, absolutely. This should be done when the system is under minimal load.
I imagine that the load on most servers is cyclical (IE, high at 9:30AM and low at 02:00AM) and crunching oodles of MD5's and comparing those to the DB would probably take a while.
Again, for conversion of existing mail-stores, yes - but as was pointed out, calculating an MD5 only happens at receipt/insertion time, so this won't be an issue for some servers.
There should obviously be a method for dealing with high-load conditions, where DBMail stores the message initially without doing the SIS work, but flags it for processing later when the load goes below a pre-configured level.
All this should be configurable by the admin, of course...
Although as an indicator I timed an md5sum on a 2.4gb file and got about 48 seconds (Pentium D ~2.8ghz or so, 15krpm scsi hdd, ubuntu 6.10) so at 100% cpu you can MD5 about 50mb of data per second probably not worth the hassle of a separate run. Thats not so bad. (50mb emails would (I hope) be fairly rare?)
Precisely... :) -- Best regards, Charles _______________________________________________ DBmail mailing list [email protected] https://mailman.fastxs.nl/mailman/listinfo/dbmail
