Module: mod_ajp13


Apache JServ Protocol version 1.3 (AJP13) gateway (available since lighttpd 1.4.59)


lighttpd mod_ajp13 is a gateway implementing Apache JServ Protocol version 1.3 (AJP13).

mod_ajp13 config options:

  • ajp13.server: backend server definition(s) for hosts to which to send requests; options for each backend host. Every file-extension can have its own handler. Load-balancing is done by specifying multiple hosts for the same extension.
  • ajp13.debug: debug level (value between 0 and 65535)
  • ajp13.balance: might be one of 'fair' (default), 'hash', 'round-robin' or 'sticky'.
    • 'fair' or 'least-connection' is the normal load-based, passive balancing.
    • 'round-robin' chooses another host for each request.
    • 'hash' is generating a hash over the request-uri and makes sure that the same request URI is sent to always the same host. That can increase the performance of the backend servers a lot due to higher cache-locality.
    • 'sticky' sends requests from the same (client) IP to the same backend.

Additional explanation of options can be found in the related mod_fastcgi options

Structure of ajp13.server section:

    ( <extension> => 
      ( [ "<label>" => ]
        ( "host" => <string> ,
          "port" => <integer> ),
        ( "host" => <string> ,
          "port" => <integer> )
      <extension> => ... 
  • <extension>: must be either "/..." or "...ext" for paths or extensions to pass to mod_ajp13 backend
  • <label>: optional name that shows up in the generated statistics of mod_status, useful for indicating which backend handler processed this extension
  • "host": IP of the proxy server (or DNS name, which is resolved to first IP at lighttpd startup)
    If host starts with a "/" lighttpd will try to connect to the unix domain socket
  • "port": tcp-port on the "host" used by the AJP13 backend server (default: 80)


    ajp13.server = ( "" =>
                     ( ( 
                       "host" => "",
                       "port" => 10000
                     ) )

Updated by gstrauss over 3 years ago · 1 revisions