1 ---

     2 labels:

     3 - 'Stage-Beta'

     4 summary: 'Connection-level rate limiting'

     5 ...

     6 

     7 Introduction

     8 ============

     9 

    10 On some servers, especially public ones, it is desired to make sure that

    11 everyone gets their fair share of system resources (and no more).

    12 

    13 mod\_limits allows you to specify traffic bandwidth limits, preventing

    14 any single connection hogging the server's CPU, RAM and bandwidth.

    15 

    16 Details

    17 =======

    18 

    19 mod\_limits detects when a connection has exceeded its traffic allowance

    20 and temporarily ignores a connection. Due to the way TCP and the OS's

    21 network API works no data is lost, only slowed.

    22 

    23 Configuration

    24 =============

    25 

    26 Currently mod\_limits is configured per connection type. The possible

    27 connection types are:

    28 

    29 -   c2s

    30 -   s2sin

    31 -   s2sout

    32 -   component

    33 

    34 The limits are specified like so in the **global** section of your

    35 config (they cannot be per-host):

    36 

    37         limits = {

    38             c2s = {

    39                 rate = "3kb/s";

    40                 burst = "2s";

    41             };

    42             s2sin = {

    43                 rate = "10kb/s";

    44                 burst = "5s";

    45             };

    46          }

    47 

    48 All units are in terms of *bytes*, not *bits*, so that "kb/s" is

    49 interpreted as "kilobytes per second", where a kilobyte is 1000 bytes.

    50 

    51 Compatibility

    52 =============

    53 

    54   ----- -------------------

    55   0.9   Works

    56   0.8   Doesn't work(`*`)

    57   ----- -------------------

    58 

    59 (`*`) This module can be made to work in 0.8 if you do two things:

    60 

    61 1.  Install

    62     [util.throttle](http://hg.prosody.im/0.9/raw-file/d46948d3018a/util/throttle.lua)

    63     into your Prosody source's util/ directory.

    64 2.  If you use libevent apply [this

    65     patch](http://prosody.im/patches/prosody08-mod-limits-fix.patch) to

    66     net/server\_event.lua.