- Red Hat Enterprise Linux (RHEL) with the High Availability Add-On
Useful References and Guides
This guide offers Red Hat's policies and requirements that apply to the management of applications, services, and resources by a RHEL High Availability cluster. RHEL High Availability is packaged with agents to manage applications and resource types, and users have the ability to deploy their own scripts or agents as well. Red Hat may have policies specific to individual resources or applications managed by a cluster - see the above Support Policies index for more specific coverage - whereas this guide offers policies that apply more generally to all resource types. Users of RHEL High Availability clusters should adhere to these policies in order to be eligible for support from Red Hat with the appropriate product support subscriptions.
Resource-agents that Red Hat ships: Red Hat distributes the
resource-agents software package via the RHEL High Availability Add-On, which provides agents to manage various applications and components that may need to be made available or shared in a High Availability cluster. Red Hat provides support for all of these agents - unless otherwise noted, and subject to all other general policies, requirements, and limitations covering RHEL and RHEL High Availability. The following conditions apply to Red Hat's support for these agents it ships:
Some Red Hat-provided agents manage an application or component that is not shipped or supported directly by Red Hat - examples include
SAPDatabase, among others. Red Hat's scope of support is specific to the resource-agent and the cluster's interaction with it, whereas concerns with the behavior of the underlying application or component may require assistance from the vendor of that component.
The applications or components managed by Red Hat's resource-agents may have their own support policies, limitations, or requirements, and Red Hat's support for the resource-agent itself does not change those existing policies. While Red Hat's resource-agents are meant to facilitate usage of the targeted components within a RHEL High Availability cluster, if some condition or policy specific to that component prevents that, it supersedes Red Hat's offer of support for the agent itself.
Some of Red Hat's resource-agents may be designed to work only in specific configurations, with specific versions of the target component, or under certain conditions. While Red Hat aims to make these conditions clear when they are known, some limitations or unhandled conditions may be unknown - especially in the case of agents dealing with components that Red Hat does not ship. Red Hat's support and development will use its own discretion in targeting improvements to these agents to cover gaps, corner cases, or unhandled conditions - and all such conditions may not be known up-front due to the frequently-changing nature of some components being managed. As such, it is important that organizations utilizing Red Hat's resource-agents thoroughly test behaviors under the specific conditions in which they are expected to function in order to identify if handling and functionality is adequate for the purposes of that deployment.
Cluster-managed services and scripts that Red Hat ships: Red Hat distributes various
lsb scripts, and SysVinit scripts as part of its products. RHEL High Availability may offer capabilities to manage such components within a cluster directly. The High Availability product's capabilities in this area are not a guarantee that every such script, unit, or component will behave as desired when integrated into the cluster. Red Hat will use its own discretion in targeting improvements or changes to either the High Availability product or individual services and scripts if they are found to not function ideally in a cluster context. Red Hat Support may offer assistance in a commercially reasonable basis to achieve a working cluster configuration that leverages such components or scripts, but no assurances can be offered that every such component will be manageable flawlessly. In some cases the organization deploying the cluster may need to develop its own mechanisms or practices for managing these components - mechanisms and practices which would fall outside the scope of Red Hat's support.
3rd-party or custom resource-agents, services, or scripts: Such cluster-managed agents, scripts, or components that Red Hat does not ship or provide support for are outside the scope of Red Hat's support for its cluster software. Red Hat may choose to offer assistance with such components in a commercially reasonable manner at its own discretion. However, concerns with such components may require the assistance of their vendor or developer.
- In clusters that manage a 3rd-party component, resource, or application - Red Hat would not consider the entire cluster to be entirely unsupported. Red Hat's scope of support would cover the components that it ships, according all relevant policies and requirements. If a support engagement is focused on a concern in which the behavior of a 3rd party component is suspected to be contributing, Red Hat may require that the behavior be reproduced or diagnosed without the involvement of the 3rd party component.
Management of applications that Red Hat does not ship: Organizations are free to use RHEL High Availability to manage their own applications or those of other vendors. Red Hat may even provide resource agents for some applications that are not products that it produces or ships directly. In such cases, Red Hat's scope of support may be limited to just the products that it ships directly or explicitly offers support for. The vendor of the managed product may need to offer their assistance to resolve concerns or problematic behaviors, and Red Hat's assistance may only be able to cover the behavior of its own software components such as the High Availability software and resource-agents it develops.