Managing the Store & DAG: EXCERPT from Microsoft® Exchange Server 2013 Inside Out

Managed Availability and the Managed Store

All access to a mailbox is gained by the protocol stack running on a Mailbox server. If a protocol such as Outlook Web App is down, all active databases on a server cannot be accessed through that protocol. The introduction of the Managed Availability system to Exchange 2013 is of huge importance to the Store because it provides a framework to measure the health of components and then takes action to restore service for problematic components.

The Managed Availability worker process (MSExchangeHWWorker) is responsible for three major functions that are designed to detect and address protocol failure. Probes operate at regular intervals to assess the health of components by reference to performance counters ...