5.2.1 High Availability performance

PVSR is able to provide high availability because of its measurement server groups, and run as a HA system. Different strategies must be applied depending on the number of machines serving PVSR and its Oracle database. However, it is true for all cases that except the nonmeasuring server components, it is recommended to install all of them on the same machine with Oracle. At most, the report and threshold modules could be relocated to another machine if there is enough capacity.

·       Located on two machines: In this case, the measurement server groups should be created so that each of them contains a measuring server in both the computers, and the primary data collecting server should be set to the measuring server not running on the same machine than Oracle. The reason for this is not only the load distribution of tasks. The PVSR registers the failure of a module in the database. If there is no primary server set and the computer running Oracle stopped working, nothing would continue to measure a part of the equipments because the measurement server on the other machine would not be notified and it would not take over the configuration data of these pieces of equipments.

·       Located on more machines: In this case a measuring server should be installed on all machines that do not run Oracle, and the primary measurement server parameter should be left blank.