/==============================================================================\
| The Wackamole Program.                                                       |
| Copyright (c) 2000-2001 The Johns Hopkins University                         |
| All rights reserved.                                                         |
|                                                                              |
| Wackamole is developed at the Center for Networking and Distributed Systems, |
| The Johns Hopkins University.                                                |
|                                                                              |
| The Wackamole package is licensed under the CNDS Open Source License         |
| You may only use this software in compliance with the License.               |
| A copy of the license can be found at                                        |
| http://www.backhand.org/wackamole/license                                    |
|                                                                              |
| Wackamole development was partially funded by a grant from the Defense       |
| Advanced Research Projects Agency (DARPA) to Johns Hopkins University. The   |
| U.S. Government retains certain rights in this software.                     |
|                                                                              |
| This product uses the Spread toolkit, developed by Spread Concepts LLC.      |
| For more information about Spread see http://www.spread.org                  |
|                                                                              |
| This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF        |
| ANY KIND, either express or implied.                                         |
|                                                                              |
| Creators:                                                                    |
|    Yair Amir             yairamir@cnds.jhu.edu                               |
|    Ryan Caudy            wyvern@cnds.jhu.edu                                 |
|    Aashima Munjal        munjal@jhu.edu                                      |
|    Theo Schlossnagle     jesus@cnds.jhu.edu                                  |
|                                                                              |
| For a full list of contributors, see Readme.txt in the distribution.         |
|                                                                              |
| WWW:     www.backhand.org     www.cnds.jhu.edu                               |
| Contact: wackamole@backhand.org                                              |
|                                                                              |
| Version 1.2.0 Built 05/Nov/2001                                              |
|                                                                              |
\==============================================================================/

OVERVIEW

Wackamole

Wackamole is an application that helps with making a cluster highly available. 
It uses the membership notifications provided by the Spread toolkit to generate
a consistent state that is agreed upon among all of the connected Wackamole 
instances. Wackamole uses this knowledge to ensure that all of the public IP 
addresses served by the cluster will be covered by exactly one Wackamole 
instance.

Wackamole works towards achieving a balanced distribution of the clusters IP 
space between its instances.  First, each instance immediately claims its 
preferred IP address. Then, if the number of virtual IP addresses acquired by 
any two machines does differ by more than one, Wackamole will work towards 
making the them differ by one or less. Wackamole has the ability to balance 
all the IP addresses at once or do it gradually.



SOURCE INSTALL

You will need The Spread Tookit to build wackamole

1) Download the Spread Toolkit from www.spread.org and install it.

2) Either add the spread header files (found in the include directory
   in the spread download) and libsp.a for your architecture to the 
   wackamole directory, or pass CPPFLAGS and LDFLAGS to configure:

     Assuming that your spread is installed somewhere odd like: /opt/spread

	./configure --with-cppflags=-I/opt/spread/include \
		--with-ldflags=-L/opt/spread/lib

     Assuming that your spread is installed is /usr/local

	./configure --with-cppflags=-I/usr/local/include \
		--with-ldflags=-L/usr/local/lib

3) Run ./configure with the appropriate parameters.

4) Type "make all" and you should have a wackamole binary

5) Type "make install" and it will install the distribution.

Configuration
 
You will need to have a valid configuration file for wackamole. Read 
the sample wackamole.conf and create your own, or just modify it for 
your cluster. You can use --sysconfdir=<path to wackamole.conf> as a
paramater for ./configure to specify the path to the configuration file.

To run wackamole, you will need to have a Spread deamon running. If the
Spread deamon is not at its default port 4803, you will need to say 
/path/to/wackamole -s <port number>


Wackamole WILL ONLY run at "root" or superuser because it needs to aquire
IP addresses.

Nuber of virtual IPs that wackamole manages can be less than number of
machines that wackamole manages if some machines have config vip 0.0.0.0