Document auto_limit_acct and max_pps

diff --git a/raddb/radiusd.conf.in b/raddb/radiusd.conf.in
index be2d2f675d34053509a05e830e7fa7e674f840d1..bca5c863232679347dd0962bcc9118b9e9e10f6e 100644 (file)
--- a/raddb/radiusd.conf.in
+++ b/raddb/radiusd.conf.in
@@ -270,6 +270,29 @@ listen {
        type = acct
 #      interface = eth0
 #      clients = per_socket_clients
+
+       #  The number of packets received can be rate limited via the
+       #  "max_pps" configuration item.  When it is set, the server
+       #  tracks the total number of packets received in the previous
+       #  second.  If the count is greater than "max_pps", then the
+       #  new packet is silently discarded.  This helps the server
+       #  deal with overload situations.
+       #
+       #  The packets/s counter is tracked in a sliding window.  This
+       #  means that the pps calculation is done for the second
+       #  before the current packet was received.  NOT for the current
+       #  wall-clock second, and NOT for the previous wall-clock second.
+       #
+       #  Useful values are 0 (no limit), or 100 to 10000.
+       #  Values lower than 100 will likely cause the server to ignore
+       #  normal traffic.  Few systems are capable of handling more than
+       #  10K packets/s.
+       #
+       #  It is most useful for accounting systems.  Set it to 50%
+       #  more than the normal accounting load, and you can be sure that
+       #  the server will never get overloaded
+       #  
+#      max_pps = 0
 }
 
 #  hostname_lookups: Log the names of clients or just their IP addresses
@@ -648,6 +671,20 @@ thread pool {
        #  '0' is a special value meaning 'infinity', or 'the servers never
        #  exit'
        max_requests_per_server = 0
+
+       #  Automatically limit the number of accounting requests.
+       #  This configuration item tracks how many requests per second
+       #  the server can handle.  It does this by tracking the
+       #  packets/s received by the server for processing, and
+       #  comparing that to the packets/s handled by the child
+       #  threads.
+       #
+       #  If the received PPS is larger than the processed PPS, *and*
+       #  the queue is more than half full, then all new accounting
+       #  requests are discarded.  This lowers the received rate,
+       #  and over time allows the server to "catch up" to the traffic.
+       #
+       auto_limit_acct = no
 }
 
 # MODULE CONFIGURATION