Handles account lockouts, gets new passwords ahead of other domain controllers, and in the forest root domain serves as the authoritative clock. It is one of the domain operations master roles.
Also called primary domain controller emulator.
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Terms in this definition
- Domain
A way of grouping workspaces by area of the business, in support of a data mesh approach. Items take on their workspace's domain, letting you filter the OneLake catalog by it, and certain tenant settings can be passed to domain admins; domains have no effect on access permissions.
- Forest
The highest-level AD container and security boundary. Its domain trees, one or more, all use one schema, configuration and global catalog.
- Apex domain
The bare domain without any subdomain (example.com), also known as the zone apex or root domain. Since a CNAME is not allowed there, routing it to a service like Front Door relies on CNAME flattening or Azure DNS alias records.
- FSMO
Five operations master roles, each owned by just one DC: per forest, the schema master and domain naming master; per domain, the RID master, PDC emulator and infrastructure master.
Related terms
- AdminSDHolder
An Active Directory container whose permissions the SDProp process on the PDC emulator stamps onto protected group members every 60 minutes, undoing any changes made to them.
- NTP
The Network Time Protocol, on UDP port 123, which the Windows Time service relies on. Domain members take time from the domain hierarchy, which leads up to the PDC emulator in the forest root, and that server should sync with an outside source.
- SDProp
Security Descriptor Propagator, which runs on the PDC emulator, by default once an hour, and overwrites the permissions on protected users and groups with those of AdminSDHolder.
- Windows Time service
The Windows service that keeps clocks in sync using NTP. Domain members take time from the AD DS hierarchy, and the PDC emulator in the forest root domain gets it from an outside source.