Policies

All of the various configurations can get quite tricky for end users to navigate. Rather than expose all of this variation to the end users and to provide a simple interface to end users, the archiver appliance uses policies. Policies are Python scripts that make these decisions on behalf of the users. Policies are site-specific and identical across all appliances in the cluster. When a user requests a new PV to be archived, the archiver appliance samples the PV to determine event rate, storage rate and other parameters. In addition, various fields of the PV like .NAME, .ADEL, .MDEL, .RTYP etc are also obtained. These are passed to the policies python script which then has some simple code to configure the detailed archival parameters. The archiver appliance executes the policies.py python script using an embedded jython interpreter. Policies allow system administrators to support a wide variety of configurations that are more appropriate to their infrastructure without exposing the details to their users.