Improve the ratelimit examples. The delay example was broken - it needed

[exim.git] / doc / doc-txt / NewStuff

diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
index 87e364df6461ca4f424cd3fa72c88f152418f1c9..556094ddfbcf655e141c78c32ecdde3f986262b4 100644 (file)
--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.73 2005/09/19 14:01:51 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.75 2005/09/22 12:58:14 fanf2 Exp $
 
 New Features in Exim
 --------------------
@@ -353,7 +353,12 @@ TF/04 There is a new ratelimit ACL condition which can be used to measure
       updated. The effect of this is that Exim measures the client's average
       rate of attempts to send email, which can be much higher than the
       maximum. If the client is over the limit it will be subjected to
-      counter-measures until it slows down below the maximum rate.
+      counter-measures until it slows down below the maximum rate. The
+      smoothing period determines the time it takes for a high sending rate
+      to decay exponentially to 37% of its peak value, which means that you
+      can work out the time (the number of smoothing periods) that a client
+      is subjected to counter-measures after an over-limit burst with the
+      formula ln(peakrate/maxrate).
 
       The leaky option means that the client's recorded rate is not updated
       if it is above the limit. The effect of this is that Exim measures the
@@ -376,13 +381,12 @@ TF/04 There is a new ratelimit ACL condition which can be used to measure
         # Log all senders' rates
         warn
           ratelimit = 0 / 1h / strict
-          log_message = \
-            Sender rate $sender_rate > $sender_rate_limit / $sender_rate_period
+          log_message = Sender rate $sender_rate / $sender_rate_period
 
         # Slow down fast senders
         warn
           ratelimit = 100 / 1h / per_rcpt / strict
-          delay     = ${eval: 10 * ($sender_rate - $sender_rate_limit) }
+          delay     = ${eval: $sender_rate - $sender_rate_limit }s
 
         # Keep authenticated users under control
         deny
@@ -396,8 +400,8 @@ TF/04 There is a new ratelimit ACL condition which can be used to measure
         # Restrict incoming rate from each host, with a default rate limit
         # set using a macro and special cases looked up in a table.
         defer
-          message = Sender rate $sender_rate exceeds \
-                    $sender_rate_limit messages per $sender_rate_period
+          message = Sender rate exceeds $sender_rate_limit \
+                    messages per $sender_rate_period
           ratelimit = ${lookup {$sender_host_address} \
                         cdb {DB/ratelimits.cdb} \
                         {$value} {RATELIMIT} }