Overview

Processes are the lifeforce of any business. Therefore, it's important to understand and carefully consider any changes you plan to make to those processes.

This page describes how to enable your process to use the new elastic process execution engine, and what impact that will have on your new or existing process.

We highly recommend you review this page in its entirety before enabling elastic scale, so that you fully understand the impacts and minimize development rework if a configuration or node you need to use is not available using the new engine.

What's supported and what's not?

It's important to know about which process model configurations are supported before you enable elastic scale. Save time developing and debugging processes with elastic scale enabled by understanding what you can do and what you can't when elastic scale is enabled for your process model.

If you're designing a new process model or flow, take a look at best practices for EPEx to familiarize yourself with recommended design implementations for specific use cases.

Configurations

This section describes which configurations are unsupported or ignored at both the process level and the node level. Refer to the next section to determine if the node or smart service you want to use is supported when elastic scale is enabled for your process model.

Unsupported vs. ignored

Unsupported configurations block you from saving and publishing the process model. Disable or remove all unsupported configurations to proceed.

Ignored configurations do not block you from saving and publishing the process model. However, each ignored case will appear as a warning describing the behavior of the ignored configuration. It is a best practice to eliminate all warnings before running your model to ensure expected behavior.

Process configurations

Location	Configuration	Unsupported or ignored?
General tab	Process Priority	Ignored
Variables tab	Process Variables > Hidden	Ignored
Process Start Form	Entire tab	Unsupported
Deadlines tab	Entire tab	Ignored
Alerts tab	Entire tab	Ignored
Data Management tab	Entire tab	Ignored
Swimlanes > Assignment tab	Assign all nodes in this lane to a person or group of people	Unsupported
Flow properties	Enable activity chaining	Ignored

Node execution limits

When elastic scale is enabled, the number of executions for each node is limited to 10,000, regardless of any node configurations. This limit is most likely to be encountered in process design using a looping flow.

Node configurations

The following configurations are unsupported or ignored on all relevant nodes in a process model where elastic scale is enabled.

Location	Configuration	Unsupported or ignored?
General tab	End condition	Unsupported
General tab	Default task priority	Unsupported
General tab	Default task priority > Allow child processes to inherit the parent process' priority	Unsupported
General tab	Quick task	Unsupported
Setup tab	Subprocess Setup > Security	Unsupported
Start Event > General tab	Activity Chaining	Ignored
Start Event > Triggers tab	Receive Message	Ignored
Start Event > Triggers tab	Timer	Unsupported
End Event > Results tab	Send Message	Unsupported
End Event > Results tab	Terminate Process	Unsupported
Escalations	Escalation Timer	Ignored
Scheduling Tab	Don't start this node until	Unsupported
Scheduling Tab	Repeat this node	Unsupported
Assignment tab	Assigned as a Task	Unsupported
Exceptions	Receive Message	Ignored
Exceptions	Timer	Ignored
Exceptions	Rule	Ignored
Other tab > Deadlines	Enable deadlines	Unsupported
Other tab > Multiple Instances	Automatically run multiple instances of this node	Unsupported
Other tab > Execution options	Refresh Default Values When Form Viewed	Ignored
Other tab > Execution options	Confirmation URL	Ignored
Other tab > Execution options	Allow users to step back to this node from the next chained activity	Ignored
Other tab > Execution options	Delete previously completed/cancelled instances	Ignored
Other tab > Execution options	Keep a record of the form as submitted for future reference	Ignored
Other tab > Execution options	Do not create if active instances exist	Unsupported
Other tab > Execution options	Delete previous instances that are still active	Unsupported

Workflow nodes

Subprocess node

The following configurations on the subprocess node are unsupported:

• Setup tab: Enable activity chaining into all initial nodes in the subprocess, Reporting, and Security.
• Scheduling, Assignment, Escalations, Exceptions, and Other tabs.

When elastic scale is enabled, we recommend using the subprocess node to kick off processes from other processes in most cases. The subprocess node is optimized to the new architecture, and the Start Process Smart Service should only be used when you need specific functionality available in that smart service, like selecting a process model using the expression editor.

When elastic scale is enabled, no more than a depth of 1000 subprocesses in EPEx can be triggered. This limit is most likely to be encountered in a recursive process design. Processes still using the existing engine have a limit of 100. When going between EPEx and the existing engine, the limit is applied depending on whichever environment you are targeting. For example, if you are starting a process with elastic scale enabled, then the EPEx limit applies.

Logic gateways (OR/XOR/AND/Complex)

When a process encounters a logic gateway, any expressions within the gateway are run by initiator by default, or whichever assignment is configured in the swimlane the logic gate is in.

OR and XOR gateways are immediately reset when the output flow is triggered. You no longer need to put an empty script task before the gate when designing a looping flow to achieve this behavior.

Script tasks

Configurations on the Scheduling, Assignment, Exceptions, and Other tabs aren't supported.

Support for plug-ins and nodes

Deprecated smart services do not work in process models with elastic scale enabled. Earlier versions of evolved smart services also do not work in process models with elastic scale enabled; for example the Write Records Smart Service (23.2) is not supported, but the updated version (23.4+) of that smart service is supported.

Plug-ins

Plug-in and smart services	Supported for Beta	Supported at GA
Excel Tools Plug-in
Import Excel to Database Smart Service	No	TBD
Import CSV to Database Smart Service	Yes	Yes
Convert Excel to CSV Smart Service	Yes	Yes
Merge Excel Documents Smart Service	Yes	Yes
Get Excel Cell by Number function	Yes	Yes
Get Excel Cell by Name function	Yes	Yes
Appian Regular Expressions Functions - Entirely supported for beta
PDF Tools Plug-in - No smart services supported
People Functions Plug-in - Entirely supported for beta
Execute Stored Procedure - No smart services supported
Advanced Document Templating Plug-in - No smart services supported
Dynamic Document Generator Plug-in
PDF from single DOCX with Fonts smart service	Yes	TBD
PDF from HTML smart service	No	TBD
DOCX Merge smart service	No	TBD
Zip File Utilities Plug-in
Unzip Smart Service	No	TBD
Zip File Detection smart service	No	TBD

Process nodes and smart services

Node or smart service	Supported for Beta	Supported at GA
Activities - supported for beta and GA
Gateways - supported for beta and GA
Events
Start Event	Yes	Yes
End Event	Yes	Yes
End Node	Yes	Yes
Receive Message Event	No	No
Rule Event	No	No
Send Message Event	No	No
Timer Event	No	TBD
Human tasks - not supported for beta or GA
AI Skills - not supported for beta, GA support TBD
Analytics - not supported for beta or GA
Business Rules
Increment Constant Smart Service	Yes	TBD
Update Constant Smart Service	Yes	TBD
Communication
Send E-Mail Smart Service	No	TBD
Send Push Notification Smart Service	No	No
Data Services
Delete Records Smart Service	Yes	TBD
Write Records Smart Service	Yes	Yes
Delete from Data Store Entities Smart Service	Yes	TBD
Execute Stored Procedure Smart Service	Yes	Yes
Query Database Smart Service	No	No
Sync Records Smart Service	Yes	No
Write to Data Store Entity Smart Service	Yes	Yes
Write to Multiple Data Store Entities Smart Service	Yes	No
Document Generation
Export Data Store Entity to CSV Smart Service	Yes	No
Export Data Store Entity to Excel Smart Service	Yes	No
Export Process Report to CSV Smart Service	No	No
Export Process Report to Excel Smart Service	No	No
HTML Doc From Template Smart Service	No	No
MS Word 2007 Doc from Template Smart Service	No	No
Open Office Writer Doc From Template Smart Service	No	No
PDF Doc From Template Smart Service	No	No
Text Doc From Template Smart Service	No	No
Document Management
Create Folder Smart Service	Yes	No
Create Knowledge Center Smart Service	Yes	No
Delete Document Smart Service	Yes	No
Delete Folder Smart Service	Yes	No
Delete KC Smart Service	Yes	No
Edit Document Properties Smart Service	Yes	No
Edit KC Properties Smart Service	Yes	No
Lock Document Smart Service	Yes	No
Modify Folder Security Smart Service	Yes	No
Modify KC Security Smart Service	Yes	No
Move Document Smart Service	Yes	No
Move Folder Smart Service	Yes	No
Reconcile Doc Extraction Smart Service	No	TBD
Rename Folder Smart Service	Yes	No
Unlock Document Smart Service	Yes	No
Identity Management - all supported for beta, not supported for GA
Integrations and APIs
Call Integration Smart Service	Yes	Yes
Call Web Service Smart Service	No	No
Invoke SAP BAPI Smart Service	No	No
Process Management
Cancel Process Smart Service	No	Yes
Complete Task Smart Service	No	No
Modify Process Security Smart Service	No	No
Start Process Smart Service	Yes	Yes
Robotic Tasks - not supported for beta or GA
Social
Follow Records Smart Service	Yes	No
Follow Users Smart Service	Yes	No
Post Comment to Feed Entry Smart Service	Yes	No
Post Event to Feed Smart Service	Yes	No
Post Hazard to Feed Entry Smart Service	Yes	No
Post System Event to Feed Smart Service	Yes	No
Test Management
Start Rule Tests (All)	Yes	No
Start Rule Tests (Applications)	No	No

Differences from the existing architecture

When you enable elastic scale, some process execution behavior is different from existing behavior. This table highlights those differences.

Summary	Current Behavior	Behavior in EPEx
Logic gates in swimlanes	Logic gates always run as the process initiator, even when in a swimlane configured to run as designer.	Logic gates in EPEx abide by swimlane configuration, but default to process initiator when the node is not in a swimlane.
Floating nodes (no incoming flow)	Any node that has no incoming flow will start when the process model is started.	Floating nodes are not supported in EPEx and will cause design time errors. Only nodes with incoming flows are executed.
Flow completion	If no flows or events are active after this node completes, the process will be paused by exception.	Flows complete when reaching a -None- state or a node with no output flow. This allows all other flows to continue and the process to complete.
Logic gate reset	Logic gates are not reset until all incoming flows have been executed. This means an OR gate with two incoming flows in a looping flow will not execute again until both flows have executed.	Execute the outgoing flows from a logic gate any time an outgoing flow is run, resetting the gate immediately.
Subprocess depth	Limited to 100.	Limited to 1000.
Node instance limit	Limited to 1000.	Limited to 10000.
loggedInUser()	When loggedInUser() is queried in a node, it is set to Administrator as opposed to the correct value (the currently logged in user)	When loggedInUser() is called in a node set to run as initiator, process initiator is returned (user or service account that kicked off the process). When a node is set to run as designer, the user that published the model is returned. At the process level (in expressions like the process name), the initiator should be returned.
Process variable size	Process variable size is unlimited.	Process variable size is restricted to 200 KB.
Process variables for subprocesses	The subprocess call does not check required process variable configurations, and will start no matter what is passed in. The Start Process smart service calls abide by required process variable configurations, and fail to start the target process if required process variables are not passed in.	Subprocess calls will not start the target process if required process variables are not passed.

Enable elastic scale

To enable elastic scale for a new or existing process:

1. In the Process Modeler, go to File > Properties.
2. On the General tab, select the Elastic Scale checkbox.
3. Continue designing your process. For a smooth experience, we recommend saving your process model periodically to review any validations related to enabling elastic scale.

Some configurations, nodes, and smart services aren't compatible with the elastic execution engine. When you validate a process model with elastic scale enabled, you'll see warnings, errors, and design guidance messages pertaining to your model's compatibility with elastic scale. These messages help you understand what you need to change or refactor before your process can execute successfully.