App BPM Configuration

Overview

The App BPM Configuration provides settings that control the behavior of the BPM execution engine, particularly the infinite loop prevention mechanism during task evaluation.

Accessing the Configuration

The configuration is accessed through the App Management system:

  1. Go to Administration > Apps management

  2. Find the BPM application card or row

  3. Click Configure (available only when the BPM app is installed)

App BPM Configuration form
The configuration form cannot be deleted, duplicated, or created manually — only one configuration record exists per application instance.

Configuration Settings

Task Evaluation Panel

The configuration form provides two settings that control infinite loop prevention during BPM task evaluation:

Field Type Default Description

Max duration (in seconds)

Integer

10

Maximum time allowed for a single task evaluation chain. When exceeded (in combination with the depth limit), the engine suspects an infinite loop and stops execution.

Max depth of recursive task execution

Integer

100

Maximum number of recursive task evaluations allowed in a single chain. When exceeded (in combination with the duration limit), the engine suspects an infinite loop and stops execution.

A suspicion of infinite loop occurs when both of these limits are exceeded simultaneously. The engine does not stop execution when only one limit is reached — both conditions must be met.

Understanding the Dual-Threshold Mechanism

The infinite loop prevention uses a dual-threshold approach to avoid false positives:

  • A long-running but shallow evaluation chain (high duration, low depth) is allowed to continue — it may simply be processing a complex task

  • A deep but fast evaluation chain (low duration, high depth) is allowed to continue — it may be evaluating many lightweight tasks

  • Only when evaluation is both long-running AND deeply nested does the engine suspect an infinite loop

This design ensures that legitimate complex process chains are not interrupted while still catching actual infinite loops.

Disabling Limits

Setting a negative value for either limit disables that specific constraint:

Configuration Effect

Duration limit = -1

No time limit is applied. Only the depth limit is checked.

Depth limit = -1

No depth limit is applied. Only the duration limit is checked.

Both = -1

Infinite loop prevention is completely disabled.
Disabling both limits removes all protection against infinite loops. Only do this in development or testing environments where you can manually stop runaway processes.

Technical Details

The configuration is stored in the AppBpm entity (com.axelor.studio.db.AppBpm), which has a one-to-one relationship with the base App entity:

Field Type Description

app

OneToOne: App

Link to the base App record

taskExecutionRecursivityDurationLimit

Integer (default: 10)

Duration threshold in seconds

taskExecutionRecursivityDepthLimit

Integer (default: 100)

Depth threshold in recursive calls

These values are read by the task evaluation engine (WkfTaskServiceImpl) during BPM process execution.

See also: Task Evaluation for details on how these limits are enforced during process execution.