APM Agents - There is currently no failover for the APM Agent (Java and .NET agents) and currently no failover for the ASM Agent.
APM Command Center (ACC) - Currently not supported.
ASM On Premise Monitoring Stations - Currently high availability for OPMS is not available. However, you can configure your monitor to run on several OPMS instances, providing that you have them installed.
AXA - If installing AXA 16.4 on premise, only single node installations are supported. Multi node installs (and HA) will be supported in a future AXA release.
Postgres/Oracle - Nothing is supported out of the box. However, Postgres/Oracle and third-party software has solutions that will work with APM