Oh, and you don't mention the versions you are using but there's a hotfix for the nas_api_service
It's release notes are:
Package: nas-api-service 8.51
Release Date: 01-25-2017
Issues resolved:
- improved performance retrieving alarms to display in USM
- resolves an issue where alarm status in USM reverts to "all green" every few minutes
- improved performance displaying large amounts of historic alarms
This should be deployed to the primary hub. It will not appear as an installed probe, but runs
as a service within the Trellis probe.
This package applies to UIM 8.4 or higher only. These issues are resolved in UIM 8.51.
Perhaps that will help.
CA Unified Infrastructure Management Hotfix Index - CA Technologies