Keepalived for Linux

Keepalived for Linux is a robust, free and open source command-line software implemented in C and designed from the offset to implement a powerful and complete keepalive daemon into the Linux Virtual Server (LVS) project.

Features at a glance

Key features include multilayer TCP/IP stack checks, support for implementing a framework based on the Layer3, Layer4 and Layer5 checks, as well as to check the pool states of a LVS (Linux Virtual Server) server.

In addition, Keepalived implements a standalone VRRP (Virtual Router Redundancy Protocol) v2 stack, which can handle director failover. The project has been specifically designed to work only with Linux kernel-based operating systems.

Among its command-line options, we can mention the ability to use a custom configuration file, run only with VRRP or Health-checker subsystems, use a specific PID file for parent process, checkers child process or VRRP child process, as well as to set the syslog functionality to LOG_LOCAL and redirect log messages to local console.

Additionally, user will be able to add options for preventing the removal of VRRP VROUTEs and VIPs, as well as IPVS topology when the daemon is stopped. It is also possible to add and option for preventing respawn of child processes or an option for preventing forking of the daemon process.

Getting started with Keepalived for Linux

To install and use the Keepalived program on your GNU/Linux distribution, you must download the latest version from Softoware or via its official website (see link at the end of the review), save the archive on a location of your choice and unpack it.

Open a Terminal app, go to the location of the extracted archive files (e.g. cd /home/softoware/keepalived-1.2.13), run the ‘./configure && make’ command to configure and compile the program, followed by the ‘sudo make install’ command to install it system wide.

What is new in this release:

• Bug fixes brought by last merge.

What is new in version 1.2.14:

• VRRP bugfixes and extensions.
• IPVS bugfixes and code code cleanup.

What is new in version 1.2.12:

• This release fixes memory reallocation.

What is new in version 1.2.11:

• This version fixes some minor memory leaks, adds better libnl support and selection, and adds some cosmetics.

What is new in version 1.2.10:

• VRRP unicast TTL fix.
• Support to newer libnl.
• More IPv6 support.
• Fixes/extends VRRP gratuitous ARP handling.
• Supports xmit VRRP packets from the base VMAC interface.
• VRRP multicast group tweaking.
• Fixes VRRP socket sync while leaving FAULT state.
• Code cleanup and cosmetics.

What is new in version 1.2.8:

• This version adds support for VRRP unicast.
• It adds support for VRRP IPv6 routes.
• It adds support for LVS One-Packet Scheduling.
• It adds a CLI core framework.
• There are miscellaneous bugfixes, typo corrections, and cosmetic changes.

What is new in version 1.2.7:

• This version fixes an issue while using vrrp_script.
• It extends SNMP to support routerId.

What is new in version 1.2.6:

• This version fixes shadow declarations.
• It fixes VRRP macvlan interface handling while reloading.
• It fixes VRRP shutdown to notify other routers before it does any action affecting traffic flow.
• It will stop VRRP timers before shutting down instances.
• It fixes VRRP socket freeing.
• It extends the VRRP script framework to support separate timeout.
• There are some cosmetic changes.

What is new in version 1.2.3:

• Pending patches have been merged.

Requirements:

• Linux Virtual Server