Configuring HULFT with LifeKeeper

Configuring HULFT with LifeKeeper

This section outlines definitions and examples of typical HULFT Recovery Kit configurations and provides information you should consider before you begin configuring HULFT.

Configuration Definitions and Examples

HULFT allows you to install multiple HULFT environments on a single system. These are independent, and each HULFT environment is referred to as a HULFT instance here. Furthermore, the state where multiple HULFT instances are running on a single system is referred to as multi-instance. Each HULFT instance possesses its own unique “HULFT System Environment Configuration File” and “Virtual IP Address”.

The HULFT System Environment Configuration File defines the system operation settings for HULFT. Each HULFT setting described in this file determines the host name, port number, process multiplicity, and other parameters used by that instance.

The HULFT resource hierarchy in LifeKeeper corresponds to one HULFT instance.

Active/Standby Configuration and Active/Active Configuration

HULFT is referred to as an active/active application in LifeKeeper, which means that HULFT supports multiple instances. For example, consider a scenario where each of two servers runs one HULFT instance. If one server fails, the HULFT instance on that server is failed over to the other server and continues running. Applications that do not support multiple instances are referred to as active/standby applications. HULFT can be configured to operate in either mode. By launching HULFT instances on multiple servers, static load balancing can be achieved. In addition, load can be distributed after a failover by adjusting the server priority settings.

HULFT Configuration Considerations

Before creating the HULFT resource hierarchy, make sure that the following HULFT configurations have been completed.

1. The host name corresponding to the LifeKeeper protected virtual IP Address should be specified for the local host name (myhostname).
   However, if node switching is performed using an FQDN (Fully Qualified Domain Name) instead of a virtual IP address (Recovery Kit for Route 53 or AWS Network Load Balancer), specify the FQDN as the local host name (myhostname).

2. A separate HULPATH directory (HULFT System Environment Configuration File storage directory) needs to be created for each HULFT resource hierarchy. Each HULFT resource hierarchy uniquely corresponds to a HULFT instance, along with its associated HULPATH directory. Note that the HULPATH directory should be the same on all servers that are configured for the HULFT resource hierarchy.

3. HULPATH should be placed on a shared file system. On the other hand, the HULEXEP directory (execution modules storage directory) should be placed on the local file system.
   

4. Recovery Kit for HULFT controls and monitors of the following HULFT demon process:

• hulsndd
• hulrcvd
• hulobsd
  The following commands are used for control and monitoring:
• hulclustersnd
• hulclusterrcv
• hulclusterobs