Adding new group rule and clicking "Preview" removes existing group members in DX NetOps Performance Management

Products

• Network Observability

Issue/Introduction

When adding a new rule to a group that already contains members (e.g., 100 interfaces), clicking the Preview button causes the existing members to disappear from the preview list. Only the results of the new rule being configured are displayed, which may lead users to believe the original members have been deleted.

Cause

This is the intended functional design of the Preview button within the group rule configuration UI. The Preview feature is designed to validate the syntax and return the results of the individual rule currently being edited or created, rather than displaying the cumulative membership of the entire group.

Resolution

To ensure that new interfaces or items are added without replacing the existing membership, follow these guidelines:

1. Understand Preview Scope: Recognize that the Preview button only shows what the current rule will include. It does not reflect the final group state once all rules are combined.
2. Use Sub-rules: Instead of replacing a broad rule, add a sub-rule to the existing group configuration to include the new criteria alongside the original logic.
3. Save and Validate: After configuring the new rule, click Save. Navigate to the group's Members tab to verify that the cumulative count (original members + new members from the additional rule) is correct.
4. Avoid Rule Conflict: Ensure that the logic of the new rule does not explicitly exclude the original members (e.g., using "Exclude" logic that conflicts with "Include" logic).

Note on Performance: If you are using Regular Expressions (RegEx) in your group rules, be aware that these are slower to process than simple "is" or "contains" matches. For groups with a high volume of items, consider using specific attributes to maintain optimal performance.