To conserve license consumption by agents when the system cannot detect its vCPU information because of asynchronous nature of reported vCPU information, AppDynamics enables the delayed fallback mode by default. This mode allows all the agents associated with the license rule to temporarily register with zero license units instead of rejecting them for a few minutes before they start consuming fallback units. This approach prevents the license usage spikes and loss of data. If the vCPU count is still unknown after 10 minutes, the agents start consuming the fallback license units.

On the Create APM License Rule page, the delayed fallback mode is represented by the the ALLOW AGENTS TO TEMPORARILY REGISTER WITH 0 UNITS ON HOSTS LACKING vCPU INFORMATION toggle. This toggle is always ON.