Description of AMS. More...
Description of AMS.
The OpenClovis Availability Management Framework (AMF) is built with the close association of two OpenClovis ASP components: Component Manager and Availability Management Service (AMS). These two components work together as defined by the Service Availability Forum. AMS is the primary decision making entity in the system with regard to the system model. It describes the various software and hardware components, attributes, inter-dependencies, service grouping rules and policies to apply in the event of failure. The CPM is the operational manager entity and is responsible for actually managing the various life cycles, based on configured policy and directions from the AMS.
AMS is a software entity that provides a framework for high availability of applications in a system. It is responsible for instantiating and managing all the application components in a system. AMS executes configured recovery actions on the failure of application components. It also escalates the faults to larger scope as per the pre-configured escalation rules.
AMS maintains the view of one logical cluster that comprises of several cluster nodes. The information model maintained by AMS is in accordance with the SAF specifications. AMS keeps track of various entities such as Node, Service Group, Service Unit, Service Instance, Component and Component Service Instance. Please refer to the SAF specifications to know more about the terms and definitions associated with AMS.
AMS stores information about attributes of the resources, their dependencies, rules for grouping them together for providing services, their current state, and the set of policies to be applied during failures. Using OpenClovis IDE, you can configure the desired availability policies with AMS on how to recover in case of failure of an application component.
The Availability Management Service administrative operations are applicable to the AMS entities. The administrative operation on an AMS entity will affect all the contained entities. For example, locking an SU would result in all the components belonging to that SU getting their work removed and switched over to the standby SUs.
The administrative operation on AMS managed entities can be performed by using ASP Console. They can also be done by using the AMS management APIs. Please refer to the API usage examples section demonstrating the usage of some of the admin APIs.
The Availability Management Service query operations are applicable to the AMS entities. The AMS management operations can be used to get the config, status of AMS managed entities. It could be also used to get the containment information of a particular entity. Examples include getting entity config and status information for an SG, getting the SU list for a given SG or Node, getting the assigned SU list for the SG, getting assigned SI list for the SG or SU, component CSI list. These operations are enabled if the application using the management service APIs are compiled with the CL_AMS_MGMT_FUNC macro. Please refer to the API usage examples section demonstrating the usage of some of the APIs.