There is a program called arbitrator after TDengine install? but it is never used since I installed TDengine and set up a cluster with 3 servers. My question is what is TDengine arbitrator and how to use it or when to use it?
Arbitrator simulates a vnode or mnode working, but is simply responsible for networking, and does not handle any data insertion or access. As long as more than half of the vnodes or mnodes, including the Arbitrator, work, the vnode group or mnode group can normally provide data insertion or query services.
You can download the arbitrator installation package and run it manually.
The command line parameter -p of this application can specify the port number of its service, and the default is 6042.
Modify the configuration file of each taosd instance, and set parameter arbitrator to the End Point corresponding to the tarbitrator in taos.cfg. (If this parameter is configured, when the number of replicas is even, the system will automatically connect the configured Arbitrator. If the number of replicas is odd, even if the Arbitrator is configured, the system will not establish a connection.)
The Arbitrator configured in the configuration file will appear in the return result of instruction SHOW DNODES; the value of the corresponding role column will be "arb".