[NIFI-4298] NiFi allows users to remove critical Attributes that are needed by processors.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.0
• Fix Version/s: 2.0.0-M3
• Component/s: Core Framework
• Assignee: Unassigned
• Reporter: Matthew Clarke
• Created: 14/Aug/17 19:57
• Updated: 09/May/24 23:21
• Resolved: 09/May/24 23:21

Description

The UpdateAttribute processor provides users with the ability to provide a "Delete Attributes Expression".

While FlowFile properties entryDate, lineageDate, fileSize, and uuid are protected and can not be removed, FlowFile attributes path and filename can be removed.

Removal of these attributes has adverse affects on many other processors. Any processor that will write a FlowFile out requires the filename attribute.

In addition, I have found that the MergeContent processor (configured to use FlowFileStreams as the merge strategy). also, for whatever reason, requires that the path attribute exists on the FlowFile.

If this attribute is missing, a NPE is thrown and the session is rolled back.

2017-08-14 19:27:00,156 ERROR [Timer-Driven Process Thread-7] o.a.n.processors.standard.MergeContent MergeContent[id=d7213e1f-0c03-1715-93cc-b1be9228ec36] Failed to process bundle of 1 files due to java.lang.NullPointerException; rolling back sessions: {}

A stack trace is not produced even if DEBUG is enabled for this processor.

NiFi needs to prevent users from being able to remove attributes which may be "required" by other processors.

Issue Links

• is fixed by: NIFI-13200 Framework should not allow removal of 'filename' or 'path' attributes
• is related to: NIFI-8971 Remove Legacy FlowFile Attributes from Content and ListenHTTP Processors