Operation in Master Mode
A master is a FlowForce Server instance that continuously evaluates job-triggering conditions and provides the FlowForce service interface. The master is aware of worker machines in the same cluster and may be configured to assign job instances to them, in addition to or instead of processing job instances itself.
When you configure a FlowForce Server instance as the master, work will not yet be distributed, since there are no workers to take over the workload. To set up a cluster, install additional FlowForce Server instances and convert them to worker mode, as shown further in this documentation. A cluster ready for load balancing is assumed to be set up when at least one machine acts as a worker, in addition to the master machine.
Only one master machine can exist in a cluster; the number of workers is not limited.
There is no difference between operating a standalone FlowForce Server instance compared to a master instance. You configure jobs and view the processing log in exactly in the same way. The only difference is that the master communicates with workers from the same cluster. On the cluster-management page, you can view at all times the list of workers joined to the master, including those that attempted to join but did not confirm the security token. From this page, you can generate security tokens to confirm workers as such, and you can also remove workers completely. For further information, see Operation in Worker Mode.
The master machine is responsible for continuous provision of service, collecting the status of job instances assigned to workers, and reporting the outcome. For this reason, it is important that the master machine be balanced according to the demands of your processing environment. To achieve that, you can redirect some or all jobs into queues that will be processed by workers, while the master will mainly provide the service interface. The master may also be configured to take some processing workload itself, in the event that no workers are available (see Distributed Execution Configuration).
Enable master mode
To enable master mode, follow the instructions below:
1.To be able to work in master mode, you will need to enable it on the FlowForce Server Setup page. Depending on your operating system, the instructions on how to access the Setup page vary:
2.When you access the Setup page, click the Configure Parameters button in the block of the server instance for which you would like to enable master mode. This opens the page with the network settings.
3.Navigate to the section FlowForce Server | Master Instance Encrypted Connection.
4.Select the Enabled check box.
5.Specify the address and port where the master instance should listen. Note that this port must be different from the port numbers used by the FlowForce Server and FlowForce Web Server services.
You can then proceed to add workers to the cluster. To do this, install new FlowForce Server instances and convert them to worker mode. For details, see Operation in Worker Mode. Note that you will need to confirm manually the security token of each worker before it is joined to the master.