Installing and Using EMS
The Role of EMS HA Monitors in a High Availability Environment
The Role of EMS HA Monitors in a
High Availability Environment
The weakest link in a high availability system is the single point of failure. EMS HA Monitors can be used to report information that helps you detect loss of redundant resources, thus exposing single points of failure, a threat to data and application availability.
Because EMS is a monitoring system, and does not do anything to modify the system, it is best used with additional software that can take action based on the events sent by EMS. Some examples are:
•EMS HA Monitors and MC/ServiceGuard
MC/ServiceGuard uses the EMS monitors to determine the health of resources, such as disks, and may fail over packages based on that information. Configuration of EMS monitoring requests for use with MC/ServiceGuard packages is done from the Cluster area for Package Configuration in SAM, or by editing the ASCII package configuration file.
However, if you also want to be alerted to what caused a package to fail over, or you want to monitor events that affect high availability you need to create requests from the SAM interface in the Resource Management area as described in “Using EMS HA Monitors” on page 17, and in subsequent chapters.
MC/ServiceGuard may already be configured to monitor the health of nodes, services, and subnets, and to make failover decisions based on resources status. Configuring EMS monitors provides additional MC/ServiceGuard failover criteria for certain network links and other resources.
•EMS HA Monitors with IT/Operations or Network Node Manager
EM HA Monitors S can be configured to send events to IT/Operations and Network Node Manager.
•EMS HA Monitors with your choice of system management software
Because EMS can send events in a number of protocols, it can be used with any system management software that supports either SNMP traps, or TCP, or UDP messages.
14 | Chapter 1 |