Start Parallel Runs

Learn how to start parallel runs in Kognitos.

Overview

In Kognitos, a process can call and run multiple subprocesses in parallel using the start a run syntax. Starting parallel runs enables the parent process to explicitly wait for the runs, retrieve the statuses, and fetch the outputs.

This is ideal when multiple subprocesses need to run simultaneously and you need to retrieve the statuses or outputs of multiple runs.

                       Parent Process
                             │
     ┌-----------------------┴------------------------┐
     │                       │                        │
     │                       │                        │
Parallel Subprocess    Parallel Subprocess    Parallel Subprocess

How To Start Parallel Runs

This section describes how to start parallel runs using the start a run syntax.

Syntax

process each item as follows:
    start a run where
        the procedure is {subprocess}
        {input}

Parameters

1. item: Object to loop over.

2. subprocess: The name of the subprocess.

3. input: Objects to pass to the subprocess, if necessary.

Use the Process Widget

When defining the procedure name, use the Process Run Widget:

1. Type a forward slash / after "the procedure is ".

2. Select Process from the menu.

3. Select the process you want to call from the Process drop-down menu.

4. Click Save.

Example

the items are "apples", "flour", "eggs", "milk"
process each item as follows
    start a run where
        the procedure is /to make apple pie
        the ingredient is the item

Click here to walk through an end-to-end example.

Remember to Publish Your Process

You need to promote your automation from the Playground to a Process in order to start parallel runs. This applies to both the main parent process and the subprocess. Otherwise, you will get an Assertion Error saying procedure not found.

Handling Subprocess Runs

A parent process can explicitly wait for the runs of a subprocess to complete. Once all runs have finished executing, the system notifies the parent process which runs will proceed further. This allows the parent to respond accordingly, such as collecting data and output from each subprocess, or taking further action based on the results.

Adding an Explicit Wait

To add an explicit wait, include the following line into your automation after starting parallel runs:

wait for the runs

Getting Output From Parallel Runs

To get results from subprocesses that are called with the start a run syntax, use the following syntax after adding an explicit wait:

Syntax

Below is a line-by-line overview of the automation syntax. Expand each line to learn more.

retrieve data from the run(s)

What does it do? Instructs the system to retrieve data from the parallel run(s).

Where does it go? This phrase should be written on a new line.

Does it require input data? ⛔ No — This phrase does not require input data.

the fact names are

What does it do? Specifies the name of the data elements to retrieve from the parallel runs.

Where does it go? This phrase should be indented below retrieve data from the run or retrieve data from the runs.

Does it require input data? ✅ Yes — Specify one or more text values containing the names of the data elements.

Example: The fact names are "status", "name", "age"

Examples

1. Singular Run

retrieve data from the run where
  the fact names are "output sum"
get the output sum from the data

2. Multiple Runs

retrieve data from the runs where
  the fact names are "status"
get the statuses from the data

Automatic Pluralization: If there are multiple runs, the system will automatically pluralize the output in the parent process (e.g., status -> statuses).

Walkthrough: Run Parallelization

This is an example walkthrough of invoking multiple instances of a subprocess in parallel runs.

Parent Process

the department's max retry wait count is 2
the names are "Eva", "Ivan", "Leo", "Nia", "Zoe"
process each name as follows
  start a run where
    the procedure is /to greet the user
    the user is the name 
wait for the runs
retrieve data from the runs
  the fact names are "greeting"
get the greetings from the data

Line #	Description
Line 1	The wait count is set to 10 seconds (2 intervals of 5 seconds).
Line 2	A data element is defined as a list of names.
Line 3	Initiates a loop across the list of names.
Line 4	Initiates subprocess invocation using start a run where syntax.
Line 5	Specifies the name of the published subprocess to call.
Line 6	Passes input to the subprocess: the name is passed as the user.
Line 7	Sets an explicit wait for the subprocess runs.
Line 8	Explicitly retrieves the greeting output from the subprocess runs.

Subprocess

Line #	Description
Line 1	Data is defined as a string that says "Hello "
Line 2	The user is added to the end of the greeting.
Line 3	The automation outputs a greeting with the user's name at the end.

Subprocess Output

In line 9, the greetings is referenced as output from the subprocess runs. The results are:

• Hello Eva

• Hello Ian

• Hello Leo

• Hello Nia

• Hello Zoe