1. Product Training Program
Unit 3 – Routing and Chaining

2. Forking

3. What is Forking?
Forking splits up a transaction into smaller, sub-transactions.
The division is handled by splitting the data in its payload, based on a logical delimiter. Examples include an XPath expression, or the files within a zip archive.
The forked transactions also introduce parallelization into the workflow. This allows large data sets to be processed concurrently.

4. Routing

5. What is Routing?
Routing controls which target systems the data gets sent to, when there are more than one to choose from in a Route.
By default, Routing sends the data to all available targets. However, this can be changed using Routing Rules.
Routing Rules define conditions using different types of expressions, and then indicate which transport to go to if that expression evaluates as true.

6. Synchronous Responses

7. What is a Synchronous Response?
Some PilotFish modules have the option of being “Synchronous”. This means that component will wait for other modules to finish before it finishes its operation.
A good example is PilotFish HTTP Listeners. When set to “Synchronous”, they won’t send an HTTP response back to the caller until they receive a Synchronous Response.
A Synchronous Response simply tells the waiting module that the operation is was waiting on is now complete.
The response conveys the state of the Transaction Data as it is when it reaches the module sending the response. This allows the data to have additional transformations done to it while the starting module waits for the response.

8. Chaining Routes

9. What is Chaining Routes?
PilotFish Routes are designed to be chained together in larger Interfaces, to allow for more complex integrations.
Special Listeners and Transports exist for the purpose of passing data from one Route to another.
Listeners are referenced by their names, so assigning unique names to listeners that will be referenced from other routes is important.
Data is passed between Routes from a Transport in Route A to a Listener in Route B. Since Route A and Route B can have an unlimited number of Listeners and Transports, there are an unlimited number of these kind of combinations.

10. Listener Triggering

11. What is Listener Triggering?
Listener Triggering is a special, advanced form of Route Chaining behavior.
Regular PilotFish listeners run on specific, programmed polling intervals. Listener Triggering overrides those intervals, forcing the listener to run immediately.
This is useful when a listener shouldn’t be running on a regular interval, but should only be executed at specific times, with those times determined dynamically by another process.
Listeners can be set to execute on trigger only, so that only operate when triggered like this.

12. Transaction Monitoring

13. What is Transaction Monitoring?
Transaction Monitoring is the PilotFish error handling mechanism.
Transaction Monitors are assigned to each Route individually, so each Route can have its own error handling mechanism.
Any errors that occur anywhere during the execution of a Route get sent to the Transaction Monitor.
The Transaction Monitor specifies how the error will be handled. In most cases, it passes the error itself along to another Route that handles the errors.