DRAFT KB-XXXX Activity chain not working as expected

Symptoms

User does not see subsequent task even when the tasks are activity chained. The task is seen in the users tasks list instead.

Cause

The number of unattended nodes that exists between two (attended) activity-chained tasks surpasses the (default) maximum number of 50.

This can be confirmed by navigating to <APPIAN_HOME>/logs/db_PX** log and checking for entries of the following type:

[Activity Chaining] Could not chain to attended activity. Limit of 50 unattended nodes executed was reached.

Other reasons why an activity chain might break are described in this documentation.

Action

• Adding an attended activity with a simple form that says 'Click to continue' between the two chained tasks is one possible way to avoid hitting this limit.
• The chained execution node limit can be increased. See Configuring Process Execution Properties for more details". Please note that increasing this limit is not supported on Appian Cloud.
  • WARNING: Raising this limit is not recommended since it can contribute to performance degradation.

Affected Versions

This article applies to all versions of Appian.