Bug/RFE: I'll have a think about whether I can phrase something.
In the meantime, I've been playing around with the outline Jeremy suggested
on the Wiki and thought I had it working. Indeed my testing with an
artificially low rate of 2 messages per 1 minute showed:
- submitting several messages to Exim let the first few through, then
kept the rest in the queue marked "deferred"
- running "exim -q" periodically allowed more to be delivered whenever
the calculate rate dropped sufficiently
So far so good.
*But…* then I let my test server do its own thing and messages didn't go
out from the queue! :-(
After a lot of digging I discovered that the problem lies with my queue
runners being launched using Exim's "-qq2m" option rather than "-q2m",
which I do for efficiency purposes as some hosts I deliver to limit the
number of concurrent connections.
Peering closely at the debugging output from "exim -qq -d+all" it appears
that the double queue run the -qq option triggers is doing something odd:
possibly updating the ratelimit database twice, causing my artificially low
rate limit to be reached before a single message is actually delivered. As
the Specification says,
In the first stage, the queue is scanned as if the queue_smtp_domains
option matched every domain. Addresses are routed, local deliveries happen,
but no remote transports are run.
The hints database that remembers which messages are waiting for specific
hosts is updated, as if delivery to those hosts had been deferred. After
this is complete, a second, normal queue scan happens, with routing and
delivery taking place as normal.
I have no_verify set on my router, but of course this only stops it
activating during address verification. With the -qq option Exim is
actually doing two full routing runs.
*Question:* Is there some option I've not spotted that says something along
the lines of "update the ratelimit database for the first run of the -qq
option but not the second"?
In case it helps, here is my ACL:
acl_ratelimit_outbound:
accept message = :defer: Sending messages to $acl_arg1 too fast:
deferred \
[$sender_rate/$sender_rate_period (max
$sender_rate_limit/$sender_rate_period)]
ratelimit = $acl_arg2 / readonly / outbound:${lc:$acl_arg1}
warn ratelimit = $acl_arg2 / strict / outbound:${lc:$acl_arg1}
accept message = $acl_arg1
and my router:
ratelimit_outbound:
driver = redirect
no_verify
allow_defer
condition = ${if exists {CFG_D/ratelimit-table}}
data = ${lookup {$local_part@$domain} lsearch*@
{CFG_D/ratelimit-table} \
{ ${acl {acl_ratelimit_outbound} {$local_part@$domain}
{$value}} } \
fail}
Cheers,
Mike B-)
On 28 February 2018 at 10:34, Jeremy Harris via Exim-users <
exim-users@???> wrote:
> On 28/02/18 10:17, Mike Brudenell via Exim-users wrote:
> > So despite being a profound advocate of Exim, it is a little embarrassing
> > to tell people who ask me about outbound rate limiting that it's so
> > difficult in it
> Perhaps you could come up with a clean set of requirements?
> In a bug/RFE, so that others could chip in, and the need
> wouldn't be forgotten?
> --
> Cheers,
> Jeremy
>
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