Fix EPNM 5.1.3.1 Upgrade Failure Due to "Downgrade:log4j-core-2.16.0.jar"

Introduction

This document describes the solution to Evolved Programmable Network Manager (EPNM) upgrade failures.

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

• EPNM
• How to connect to the EPNM Application Server GUI and CLI with shell access

Components Used

The information in this document is based on EPNM software versions 5.0.2.1 and 5.1.3.1.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Background Information

A failure occurs when you try to upgrade to EPNM version 5.1.3.1 from EPNM version 5.0.2.1.

Problem

The error message "Unexpected library downgrade:log4j-core-2.16.0.jar" appears when EPNM upgrades to version 5.1.3.1  from version 5.0.2.1 and hinders the upgrade process. Refer to the error message as shown in this image:

Solution

Step 1. Take a backup of the log4j core files from EPNM Application Server CLI . The  commands are shown below.

#mkdir /localdisk/sftp/backup_log4j
#mv /opt/CSCOlumos/compliance/lib/log4j-core-2.17.0.jar /localdisk/sftp/backup_log4j/log4j-core-2.17.0.jar_lib
#mv /opt/CSCOlumos/lib/xmp-third-party/log4j-core-2.17.0.jar /localdisk/sftp/backup_log4j/log4j-core-2.17.0.jar_xmpthirdParty

Step 2. Once the files are backed up, install the EPNM 5.1.3.1 Security patch file (cepnm5.1-dpp3-pp1-build874.ubf) from EPNM GUI (Administration > Licenses and Software Updates > Software Update) and that installs EPNM 5.1.3.1 successfully.

Step 3. Verify the log4j-core files show log4j-core-2.16.jar under the folders /opt/CSCOlumos/compliance/lib and under /opt/CSCOlumos/lib/xmp-third-party/.

Refer to this image: