Specifications

LifeKeeper GUI Software

The LifeKeeper GUI is a client / server application developed using Java technology that provides a

graphical administration interface to LifeKeeper and its configuration data. The LifeKeeper GUI client

is implemented as both a stand-alone Java application and as a Java applet invoked from a web

browser.

LifeKeeper Man Pages

The LifeKeeper Core reference manual pages for the LifeKeeper product.

Configuration Concepts

LifeKeeper works on the basis of resource hierarchies you define for groups of two or more servers.

The following topics introduce the LifeKeeper failover configuration concepts:

Common Hardware Components

All LifeKeeper configurations share these common components:

1. Server groups. The basis for the fault resilience provided by LifeKeeper is the grouping of two

or more servers into a cluster. The servers can be any supported platform running a supported

distribution of Linux. LifeKeeper gives you the flexibility to configure servers in multiple

overlapping groups, but, for any given recoverable resource, the critical factor is the linking of a

group of servers with defined roles or priorities for that resource. The priority of a server for a

given resource is used to determine which server will recover that resource should there be a

failure on the server where it is currently running. The highest possible priority value is one (1).

The server with the highest priority value (normally 1) for a given resource is typically referred

to as the primary server for that resource; any other servers are defined as backup servers for

that resource.

2. Communications paths. The LifeKeeper heartbeat, a periodic message between servers in a

LifeKeeper cluster, is a key fault detection facility. All servers within the cluster require

redundant heartbeat communications paths (or, comm paths) to avoid system panics due to

simple communications failures. Two separate LAN-based (TCP) comm paths using dual

independent subnets are recommended (at least one of these should be configured as a

private network); however, using a combination of TCP and TTY comm paths is supported. A

TCP comm path can also be used for other system communications.

Note: A TTY comm path is used by LifeKeeper only for detecting whether other servers in the

cluster are alive. The LifeKeeper GUI uses TCP/IP forcommunicating status information

about protected resources; if there are two TCP comm paths configured, LifeKeeper uses the

comm path on the public network for communicating resource status. Therefore if the network

used by the LifeKeeper GUI is down, the GUI will show hierarchies on other servers in an

UNKNOWN state, even if the TTY (or other TCP) comm path is operational.

3. Shared data resources. In shared storage configurations, servers in the LifeKeeper cluster

share access to the same set of disks. In the case of a failure of the primary server,

40SteelEye LifeKeeper for Linux