accept-clients-in-backup-mode
Section: statserver
Default Value: yes
Valid Values: yes, no
Changes Take Effect: After restart
Modified: 8.5.1. New default value is yes
Specifies whether Stat Server accepts client connections when operating in backup mode.
With this option set to yes, Stat Server notifies the clients about its redundancy mode after a client's registration and after a change in mode. Moreover, when its redundancy mode is changed to backup, Stat Server does not close the communication port and accepts clients' connections and requests.
config-reload-delay-if-primary
Section: statserver
Default Value: false
Valid Values: true, false
Changes Take Effect: Immediately
Introduced: 8.5.112.07
This option controls whether Stat Server, in primary mode, delays configuration reloads. If this option is set to true, the primary Stat Server in the redundant pair delays the reload of the configuration when it cannot restore a session with Configuration Server. The option must be configured in both Stat Server applications of the primary-backup pair.
Protected and Normal Modes
In releases prior to 8.5.112.07, Stat Server reloads the entire configuration when it cannot restore the session with Configuration Server (normal mode). Both Stat Servers in a primary-backup pair can reload the configuration simultaneously and, therefore, the whole pair becomes unavailable, which adversely impacts Contact Center routing decisions.
Starting with release 8.5.112.07, in addition to normal mode Stat Server supports protected mode of configuration reloads for redundant pairs as a result of inability to restored the session with Configuration Server and after the HistoryLogExpired notification is received from Configuration Server. This functionality enables the Stat Server running as primary in the pair to delay configuration reloads and stay available until the backup Stat Server in the pair completes configuration reload. Backup or standalone instances of Stat Server behave as in normal mode, reloading the configuration unconditionally.
When the HistoryLogExpired notification is received from Configuration Server and the [statserver]/config-reload-delay-if-primary option is set to true, the primary Stat Server checks that the [statserver]/accept-clients-in-backup-mode option is set to yes in the backup Stat Server. If not, the primary instance reloads configuration immediately (as before 8.5.112.07 release). Otherwise, it delays configuration reload until the backup instance is up and running—it closes the connection to Configuration Server, switches to protected mode, and starts periodic checking for the backup instance readiness (by connecting to the backup instance's default client port). When the backup instance completes configuration reload and is ready to accept clients, the primary instance notifies Management Layer with the SERVICE_UNAVAILABLE status. In response, Management Layer initiates switchover and moves the current primary instance to backup mode. When the primary instance is switched to backup mode, it ends the protected mode, connects to Configuration Server, and reloads the configuration.
Stat Server generates log events when normal/protected mode starts and stops. Refer to Log Events (02-10084, 02-10085, 02-10086, and 02-10087) for more information.