On Wed, May 24, 2006 at 03:00:11PM +0200, [EMAIL PROTECTED] wrote: > > On Tue, May 23, 2006 at 03:32:03PM +0200, H. Wilmer wrote: > >> Peter D. Gray wrote: > >> > > But when the mail gets to the stores, they kind of > > get slow. It would be nice if the smtp system on the > > mail stores knew its own limits and only accepted > > email at a rate it can handle, but that is not the case. > > You mean the mail cannot be written to disk fast enough? What happens in > that case? I would just expect that this would result in an overall > slowdown until the spike has been handled. >
It is not just a question of disk r/w rates. The stores do all sorts of stuff and have some bottlenecks. > For example, if I have a 1.5 GB file in memory and want to write it to a > disk, the disk might handle 40 MB/sec, so it will just take some time to > write the file, and the process doing it will have to wait. > > Wow, you would have to have an internet connection with quite some > bandwidth for the storage system to be a bottleneck! > Not just that, if a message arrives to 1000 recipients, the stores have to do a bit of work to make that delivery, even if the message itself is small. > > I am routinely seeing mail rates of 60 per second > > for minutes at a time now, mainly spam. > > Hm, can you deploy better SPAM protection? > We do greylisting and tagging already. And I am considering freezing all messages with UCE scores higher than N and then thawing them at night. Has anybody else done this? > Otherwise, you could use _slower_ machines to run exim on. Thus, you will > get higher load averages on them and use that to keep the data flow below > what the storage can handle :) > Funny you should say that, my hubs are quite slow and I like them like that for exactly this reason. But even a slow machine can route a lot of email. Regards, pdg -- See mail headers for contact information. -- ## 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/
