.. _header_freq-plugin:

Header Frequency Plugin
***********************

.. Licensed to the Apache Software Foundation (ASF) under one
   or more contributor license agreements.  See the NOTICE file
  distributed with this work for additional information
  regarding copyright ownership.  The ASF licenses this file
  to you under the Apache License, Version 2.0 (the
  "License"); you may not use this file except in compliance
  with the License.  You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing,
  software distributed under the License is distributed on an
  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  KIND, either express or implied.  See the License for the
  specific language governing permissions and limitations
  under the License.

The Header Frequency plugin keeps track of the number of times headers
have been seen in transactions. Two separate counteres are kept for
the origin and the client. This information is accessible via ::

    traffic_ctl plugin msg header_freq log

Installation
------------

This plugin is only built if the configure option ::

    --enable-experimental-plugins

is given at build time.

Add the following line to :file:`plugin.config`::

    header_freq.so
