UCARP is a programme of high-availability for operating system Unix and derived which allows the division by several hosts of the same address IP in order to ensure the continuity of the service in the event of failure of a host. This program implements in space user the protocol CARP available under OpenBSD and is opposed to the protocol owner VRRP.

Principles

Ucarp allows the division of an address IP known as virtual by various hosts also provided with a real address IP on the network. A host is declared Master and answers the traffic emitted on virtual address IP. The other hosts are the slaves and wait to take the hand. Each host has a priority which enables him to take the hand in a given order if the main host proves to be failing.

To summarize the needs are the following:

• a single virtual address IP.
• a real address IP by host.
• a priority by host (whole from 1 to 255).
• a time of description (by defect one second) to the end of which the host sends signs of life on the network.
• a password common to all the hosts.

When the host takes the hand, it carries out a script which enables him to be organized (indeed it henceforth will receive the traffic of virtual address IP and can not be still ready with this situation). A script is also launched when a host loses the hand.

Ucarp was tested successfully on GNU/Linux 2.4, GNU/Linux 2.6, MacOS X, OpenBSD, MirBSD, Solaris and NetBSD.

Authors

Ucarp is written by Frank Denis. The " mode; neutre" was written by Russell Mosemann and Richard Bellamy helped for the portability towards Solaris.

Reference

• Files of information of the package of the sources of Ucarp v.1.2
• Official site of Ucarp

External bonds

• Official site of Ucarp

Random links:

Actinistiens | Dasyproctinae | Virgin memory | Jonas Hiller | Charles de Noyelle