Every instance of Compere in a project group can be either online or offline. If online, each will be acting as a client or as a server. Network information is shown in the main panel Status Bar, whose colour indicates the online/offline status:
grey = offline. Since it is disconnected from any group, any information may be residual from the last online state.
blue = online and in a project group that has a server.
red = this device should be online but there is a problem. You can mouse-over the warning triangle in the Status Bar or Network Discovery window to find out what the problem is (e.g.: ‘Project group has no server’, or not receiving peer data from one or more peers – the tooltip will show expected versus actual).
In the event of loss of server connection, clients continue to run with the project but no project file changes are exchanged until a server is re-elected.
Server Election
Server failover is an automatic process for reassigning the project group server role in case of server failure. If a server failure is detected and persists, Compere holds an election for a replacement, i.e. a client automatically becomes the server. Election is on the basis of preassigned scores, where each device in a project group is assigned a relative score, with highest numbers given highest priority to take over.
Failover for a project group is configured from the Network Discovery dialog, by assigning relative preference scores. Highest score wins, in the event of a tie-breaker, the MAC address sequence is used.
Some of these controls are available in the Status Bar for the local instance:
•Elections are held whenever something upsets the status quo of the system.
•There is a grace period at start-up of a system, to allow things to get up and running and scores to be compared.
•When there are no viable candidates (all score 0), an election does not run.
•The election score property is available to JSON external control. This means an election can be deliberately triggered, and even rigged if required.
The Status Bar shows you a list of counts of Compere instances (updated even when you are offline). Use this to detect missing instances in your Project Group and/or potential other GUI instances configuring your system.
Manual Server Assignment
If you do not want automatic failover, just configure a single device with a non-zero score and the rest as ‘Client only’ (0). If that device fails, adjust the score of another device to be non-zero to trigger a manual failover (reassignment).
Page edited [d/m/y]: 18/12/2023