.. _admin-plugins-mysql-remap:

MySQL Remap Plugin
******************

.. Licensed to the Apache Software Foundation (ASF) under one
   or more contributor license agreements.  See the NOTICE file
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  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
 
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  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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  under the License.


This is a basic plugin for doing dynamic "remaps" from a database. It
essentially rewrites the incoming request's Host header / origin server
connection to one retrieved from a database.

The generic proxying setup is the following::

    UA ----> Traffic Server ----> Origin Server

Without the plugin a request like::

    GET /path/to/something HTTP/1.1
    Host: original.host.com

Ends up requesting ``http://original.host.com/path/to/something``

With this plugin enabled, you can easily change that to anywhere you
desire. Imagine the many possibilities....

We have benchmarked the plugin with ab at about 9200 requests/sec (1.7k
object) on a commodity hardware with a local setup of both, MySQL and
Traffic Server local. Real performance is likely to be substantially
higher, up to the MySQL's max queries / second.

Installation
============

This plugin is only built if the configure option ::

    --enable-experimental-plugins

is given at build time.

Configuration
=============

Import the default schema to a database you create::

    mysql -u root -p -e "CREATE DATABASE mysql_remap;"   # create a new database
    mysql -u root -p mysql_remap < schema/import.sql     # import the provided schema

insert some interesting values in mysql_remap.hostname &
mysql_remap.map

Traffic Server plugin configuration is done inside a global
configuration file: ``/etc/trafficserver/plugin.config``::

    mysql_remap.so /etc/trafficserver/mysql_remap.ini

The INI file should contain the following values::

    [mysql_remap]
    mysql_host     = localhost   #default
    mysql_port     = 3306        #default
    mysql_username = remap_user
    mysql_password = 
    mysql_database = mysql_remap #default

To debug errors, start trafficserver manually using::

    traffic_server -T "mysql_remap"

And resolve any errors or warnings displayed.
