Specify the Execution Queue Limit of a Python Program

The Python Program tab on the configuration form of a Python Program includes an Execution Queue Limit field.

Geo SCADA Expert can run several Python programs simultaneously, however it can only run one instance of a specific Python program at a time. If you want Geo SCADA Expert to execute further 'Run' requests that occur for the same Python program while that program is running, you can get Geo SCADA Expert to queue those further 'Run' requests. Several 'Run' requests might occur, for example, if users on two different machines trigger a 'Run' of the same Python program. With any 'Run' requests that are queued, Geo SCADA Expert will execute those requests in the order in which they appear in the queue, once the current run has finished.

Use the Execution Queue Limit property to define the maximum number of 'Run' requests that Geo SCADA Expert is to store in the execution queue for this particular Python program. Typically, the default Execution Queue Limit of 20 is appropriate. If this limit is reached, Geo SCADA Expert will discard any further 'Run' requests that it receives for this particular Python program. Once the number of queued requests has dropped below this limit, Geo SCADA Expert will accept any new 'Run' requests that it receives for this program, up to and including the limit configured in this field.

Be aware that the Geo SCADA Expert server has its own overall Execution Queue Limit. The value of that property takes precedence over the sum of the execution queue limits that exist for individual Python programs (see Define the Program Limits on the Server).