Directory failover and load balancing ensure that multiple Directory servers work together to maintain continuous access to configuration data, distribute client load evenly, and recover reliably from server failures. These capabilities depend on how Directory components operate and on how all Directory servers start and participate in elections and load distribution.
- Directory role
- Manages system configuration and handles failover for all other roles.
- Directory database
- Stores system configuration. Configure this database in Server Admin. The default
name is
Directory.
Differences between secondary Directory servers and the main Directory server
- Secondary Directory servers
- Secondary servers are assigned to host the Directory role. The Directory role can
run on up to five servers simultaneously for load balancing. These servers share the
workload for credential authentication, software license enforcement, Directory
database report queries, and similar tasks.
Users can log on to Security Center through any Directory server. By default, the Directory Manager role redirects connection requests across all Directory servers in a round robin pattern, but you can bypass load balancing on specific workstations when needed.
- Main Directory server
- Also known as the main server (
), the main Directory
server is the primary server assigned to host the Directory role. Only the main
Directory server has read and write access to the Directory database. All other
Directory servers (
)
have read-only access to the database.
When a secondary Directory server fails, only the client applications connected through that server must reconnect. When the main Directory server fails, all clients on the system must reconnect, and the system assigns the main server responsibilities to the next Directory server in the failover list.
Required startup behavior for Directory servers
Because Directory failover and load balancing rely on all Directory servers working together, all Directory servers are expected to start together. Directory assignment, failover, and load balancing processes are handled automatically.
Delaying the startup of Directory servers provides no stability or reliability benefit and can temporarily increase load on Directory servers. All servers in the Directory failover list must have the Genetec Server Windows service started at the same time, or as close to the same time as possible.
Why simultaneous startup is required
When the Genetec Server service starts on a Directory server, it immediately does the following:
- Discovers all other configured Directory servers.
- Participates in the main Directory election and load distribution.
If Directory servers are started with long delays between them, the system temporarily operates with a reduced Directory pool. This results in the following conditions:
- Client applications are distributed across fewer Directory servers.
- Load distribution becomes uneven.
- Load increases on the servers that start early.
Correct startup procedure for Directory servers
When starting or restarting a system with multiple Directory servers:
- Start the Genetec Server Windows service on all Directory servers concurrently.
- If simultaneous startup is not possible, start the services within the shortest possible time window.
- Do not wait for a Directory server to fully initialize or assume the main server responsibilities before starting the next.
There is no required startup sequence between Directory servers. The following actions provide no benefit:
- Starting the primary Directory server first.
- Starting secondary Directory servers in a specific order.
- Waiting for a Directory server to become the main Directory.
- Manually “letting the system settle” before starting additional Directory servers.