DX NetOps 25.4.9 Upgrade - Missing SNMP/Non-SNMP data in all views and mediation manager Failures

Products

• Network Observability

Issue/Introduction

Following an upgrade of DX NetOps from version 25.4.4 to 25.4.9, users may encounter the following critical symptoms:

• Mediation Manager (Non-SNMP Monitoring): Monitoring stops functioning, and no metrics are collected or displayed.
• SNMP Monitoring : The views fails to display the full inventory/data of monitored devices.

Environment

• Product: DX NetOps
• Version: 25.4.9

Cause

The issue is a scale-related side effect of a security hardening fix introduced in the 25.4.9 codebase. A JVM deserialization filter (jdk.serialFilter) implemented for security rejects messages if they contain arrays exceeding a hardcoded limit of 200,000 entries.

Large environments (e.g., those with large Discovery Profiles or high device counts) may trigger this limit, leading to a java.io.InvalidClassException: filter status: REJECTED error in the Data Collector (DC) logs, which interrupts polling and inventory synchronization.

Resolution

Workaround

To stabilize the system and restore visibility in the dashboards, perform a global polling reset:

1. Stop polling for all devices.
2. Start polling for all devices.

Refer to KB 264417 for the specific steps to stop and start polling across the board.

Alternatively, you can manually increase the maxarray limit in the DC configuration:

1. Navigate to /opt/IMDataCollector/scripts.
2. Backup the dcmd script.
3. Edit dcmd and locate the APP_OPTS section containing -Djdk.serialFilter.
4. Change maxarray=200000 to maxarray=1000000.
5. Restart the Data Collector service.

Additional Information

Resolution

This issue is formally tracked under defect DE209377. Engineering is increasing the default array maximum limit to 1 million entries.

Fixed Version: This fix is scheduled to be included in the DX NetOps 25.4.11 release.