On Tue, Feb 27, 2001 at 10:13:28AM -0800, Brandon Yu wrote:
> The messages themselves have been pre-generated and exist as a file and is
> qmail-injected to place them in the queue. The message is the same across
> the board with the exception of some personalization, such as the name.
> Since there are so many messages, we use a perl script to place them in the
> queue at a certain rate, i.e. 50 msgs/second, or whatever rate we choose. By
> injecting them at this rate, we can see whether qmail can keep up with our
> intended rate. With this in mind, does this lessen the burden of disk I/O?
As long as you are injecting messages, qmail won't perform at full
speed. Play with that rate, maybe no limiting *is* the best option.
> I have heard of DNSCACHE, currently BIND is running directly on those
> machines. Would it be worthwhile changing out? Can I expect to relive a
> bottleneck in this process?
If you're sending out that many mails, I wouldn't be surprised if BIND
kept on caching all data and eventually filled all available memory.
Since BIND doesn't limit it's memory use, it will grow as long as
records don't expire. Extreme growth breaks your server, less extreme
growth still limits the amount of memory your OS can dedicate to disk
caching and buffering, which hurts performance.
Use dnscache :)
> Why would you avoid sorting by domain? I would think it would be more
> efficient handshaking.
If you insert 10.000 messages to the same domain together, qmail will
be spending lots of time on all these messages before it handles
messages for another domain. If this domain is down, it will
bottleneck the rest. If you don't care about domains at all, it's much
harder for a single domain to use all your remote concurrency.
> No, I am not using EZMLM. How could I benefit from using it?
ezmlm is an instantly-working mailinglist tool, that saves you time
coding. It also injects a message into the queue *once*, which means
there is no I/O problem. qmail then delivers this *one* message to
*all* recipients, in such a way that ezmlm can do reliable
bouncehandling.
Greetz, Peter.
