Redmine

Summary
When updating the due date of an issue that has deep and/or many issue relations, the execution time of the update increases significantly.
As the number or depth of related issues grows, the operation may take a very long time or eventually time out.
This appears to be a performance and scalability issue rather than a functional bug.

• Updating the due date of a root issue

• Issues are linked by multiple levels of relations (e.g. precedes / follows)
• The depth of the relation chain and/or the number of related issues is large

• Updating the due date triggers propagation logic to adjust related issues
• During this process, related issues are traversed recursively
• The recursive traversal of issue relations becomes the main performance bottleneck
• Execution time increases non-linearly as relation depth grows

• Updating the due date should complete within a reasonable time even when relations are deep Alternatively, the recursion depth or the number of processed related issues could be limited
• or the traversal logic could be optimized

• In projects that heavily rely on issue relations, due date updates become impractical
• The impact is more significant in large or long-running projects

• Redmine: 5.1.2
• Ruby: 3.2.3
• Database: PostgreSQL 16

• The issue may not be specific to a particular Redmine version
• The performance impact seems to originate from recursive traversal of issue relations during due date propagation
• Code paths related to IssueRelation and due date propagation logic appear to be involved,especially when relations form deep chains