Ubuntu

NiFi Version Upgrade on Bridge Client from 1.28.x to 2.6.x on Ubuntu

This article provides a step-by-step procedure to upgrade Apache NiFi from versions 1.28.x or 1.25.0 to 2.6 for both:

• Apache NiFi Server

• OvalEdge Bridge Client on Linux

The document also includes the Java upgrade procedure from JDK 17 to JDK 21, along with:

• prerequisite validation

• backup requirements

• configuration updates

• rollback considerations

• validation procedures

• post-upgrade verification steps

This guide is intended for administrators, DevOps engineers, implementation teams, and support engineers responsible for maintaining the OvalEdge Bridge environment.

Upgrade Overview

Perform the upgrade in the following sequence:

1. Verify prerequisites and current environment status.

2. Validate Bridge connectivity from the OvalEdge application.

3. Back up the existing NiFi configuration and Bridge artifacts.

4. Stop existing NiFi services.

5. Upgrade the Apache NiFi Server from 1.28.x to 2.6.

6. Update ECS task definitions and EFS mount configurations.

7. Upgrade Java from JDK 17 to JDK 21 on the Bridge Client.

8. Upgrade the Apache NiFi Bridge Client from 1.28.x to 2.6.

9. Update NiFi configuration files.

10. Restart NiFi services.

11. Validate Bridge connectivity and connector execution.

12. Verify logs, metadata extraction, and processor communication.

Supported Upgrade Paths

Component	Existing Version	Target Version
Apache NiFi Server	1.25.0 / 1.28.x	2.6
Apache NiFi Client	1.25.0 / 1.28.x	2.6
Java	JDK 17	JDK 21

Prerequisites

System Requirements

Ensure the following prerequisites are met before starting the upgrade.

Component	Supported Version
Ubuntu Server	22.04 / 24.04
Java	JDK 21
Apache NiFi	2.6

Minimum Hardware Requirements

Resource	Minimum
CPU	4 vCPUs
Memory	8 GB RAM
Disk Space	20 GB Free

Recommended Hardware Requirements

Resource	Minimum
CPU	8 vCPUs
Memory	16 GB RAM
Disk Space	50 GB Free

Network Requirements

Ensure connectivity to:

• OvalEdge Application URL

• Data Sources

• Cloud Services (if applicable)

If a proxy server is used:

• Configure proxy settings before installation.

• Verify outbound HTTPS communication.

• Validate access to OvalEdge endpoints.

Mandatory

• Root or sudo access

• Access to the OvalEdge Application UI

• Access to ECS Task Definitions

• Access to EFS mount configurations

• Sufficient disk space for backups

• Existing Bridge artifact ZIP package

• Internet access or offline installation binaries

Recommended

• Perform the upgrade during a maintenance window.

• Notify users about temporary connector interruptions.

• Export screenshots of existing NiFi flows before the upgrade.

Pre-Upgrade Validation

Validate Bridge Status from the OvalEdge UI

1. Log in to the OvalEdge application.

2. Navigate to the Bridge Monitoring page.

3. Verify the Bridge status displays:

4. Connected

5. Running

Expected Result

The Bridge status appears healthy before the upgrade begins.

Failure Impact

If the Bridge is disconnected before the upgrade, troubleshooting becomes more difficult after the migration.

Apache NiFi Server Upgrade (1.28.x → 2.6)

Stop the Existing NiFi ECS Service

Procedure

1. Open AWS Console.

2. Navigate to Amazon ECS → Cluster → Service → Tasks.

3. Stop the currently running NiFi ECS service.

   

Validation

Verify the ECS task status changes to:

Stopped

Warning

Do not continue while the existing NiFi service remains active.

Update the ECS Task Definition

Procedure

1. Open the ECS Task Definition used by the NiFi service.

2. Replace the existing NiFi Docker image with the approved NiFi 2.6 image.

3. Register a new task definition revision. Example:

   Existing Image:
   apache/nifi:1.28.1
   Updated Image:
   apache/nifi:2.6

Validation

Verify that a new ECS task revision is successfully created.

Validate EFS Mount Paths

Procedure

1. Open the ECS Task Definition.

2. Verify EFS container mount mappings.

3. Confirm all required NiFi directories are accessible.

Validate the Following Mounts

1. nificonf

2. nifilib

3. certificates directory

4. flow configuration directory

Failure Impact

Incorrect EFS mappings may cause:

• missing flows

• missing certificates

• startup failures

Back Up the Existing nificonf Directory

Mandatory

Take a complete backup of the existing nificonf directory before modifying any configuration files.

Sample Reference Screenshot:

Example Backup Command

cp -r nificonf nificonf_backup_$(date +%Y%m%d)

Expected Result

A complete backup of the NiFi configuration is available for rollback.

Retain Required Files in nificonf

Retain only the following files:

keystore.jks
nifi-cert.pem
nifi.properties
truststore.jks
users.xml

Do not remove certificate or truststore files required for secure communication.

Update the nifi.properties File

1. Open:

   nificonf/nifi.properties

2. Locate:

   nifi.flow.configuration.file=./conf/flow.xml.gz

3. Update to:

   nifi.flow.configuration.file=./conf/flow.json.gz

   Sample Reference Screenshot:

   
4. Save the file.

Purpose

NiFi 2.6 uses flow.json.gz instead of flow.xml.gz.

Validation

Verify the updated property is saved correctly.

Clean the nifilib Directory

Procedure

1. Navigate to the nifilib directory.

2. Remove all .nar and .jar files except:

   sapjco3.jar

Warning

Do not delete the SAP JCo library required for SAP connectors. Before removing any files from the nifilib directory, create a backup of the existing directory to support rollback if required.

Start the Updated NiFi ECS Service

Procedure

1. Deploy the updated ECS task revision.

2. Start the ECS service.

Validate the Following

• NiFi UI is accessible.

• Existing flows are visible.

• No certificate errors appear.

• No startup failures appear in logs.

Validation Commands

docker logs <container_name>

or

aws ecs describe-services

Expected Result

The ECS service reaches a Healthy state, all tasks start successfully, and the NiFi UI is accessible.

Update the InvokeHTTP Processor

1. Log in to the NiFi UI.

2. Open the existing InvokeHTTP processor.

3. Update:

   1. Remote URL

   2. SSL Context Service (if configured)

   3. Authentication configuration

   4. HTTP Method

   5. Request timeout settings

Example:

https://ovaledge.company.com/api

Validate the Following

• URL connectivity

• processor execution status

• successful HTTP communication

• processor scheduling state

Expected Result

Processor status displays:

• Running

• No communication errors

Apache NiFi Bridge Client Upgrade (Linux)

Environment Information

Parameter	Value
Operating System	Ubuntu 22.04 / 24.04
Existing Java Version	JDK 17
Target Java Version	JDK 21
Existing NiFi Version	1.25.0 / 1.28.1
Target NiFi Version	2.6

Verify Existing NiFi and Java Versions

Before starting the upgrade, verify the currently installed versions of NiFi and Java.

Procedure

1. Connect to the Bridge Client server using SSH.

2. Verify the NiFi service status.

   sudo systemctl status nifi

3. Verify the running NiFi process.

   ps -ef | grep nifi

4. Verify the installed Java version.

   java -version

5. Record the current NiFi installation path. Example:

   ls -ld /home/ubuntu/nifi_client/nifi-*

Validation

Verify the following:

• NiFi service exists and is currently running.

• The installed NiFi version is 1.25.x or 1.28.x.

• Java version is JDK 17.

• The existing NiFi installation directory is accessible.

Expected Result

Example output:

Apache NiFi Version: 1.28.1

openjdk version "17.x"

The existing NiFi installation and Java runtime are successfully identified before the upgrade begins.

Stop the Existing NiFi Service

Stop the currently running NiFi service before upgrading Java and installing the new Bridge Client version.

Procedure

1. Verify the current service status.

   sudo systemctl status nifi

2. Stop the NiFi service.

   sudo systemctl stop nifi

3. Verify that the service has stopped successfully.

   sudo systemctl status nifi

4. Confirm that no NiFi Java processes remain active.

   ps -ef | grep nifi

   Sample Reference Screenshot:

   

Validation

Verify:

• The NiFi service status is inactive.

• No active NiFi Java processes remain.

• No startup or shutdown errors appear in the service logs.

Optional log verification:

sudo journalctl -u nifi -n 50

Expected Result

Service status displays:

inactive (dead)

No active NiFi process is visible in the process list.

Failure Impact

Upgrading while NiFi is still running may result in:

• configuration corruption

• incomplete file updates

• Service startup failures after migration

Back Up Existing Bridge Files

Mandatory Backup Activities

Back up:

1. Existing NiFi installation directory

2. BridgeRegistration.properties

3. Existing Bridge ZIP artifacts

4. Java cacerts file

Sample backup commands

cp -r nifi-1.28.1 nifi-1.28.1_backup
cp conf/BridgeRegistration.properties \
BridgeRegistration.properties_backup

Important Files

<NiFi Installation>/conf/BridgeRegistration.properties

Important

If the original Bridge ZIP artifact is unavailable, retrieve it from the existing Bridge server temporary directory. Sample Reference Screenshot:

Install OpenJDK 21

Install JDK 21 before installing the NiFi 2.6 Bridge Client.

Installation Procedure

1. Refresh the package repository.

   sudo apt update

2. Install OpenJDK 21.

   sudo apt install openjdk-21-jdk -y

3. Verify the installation directory.

   update-java-alternatives --list

4. Configure JDK 21 as the active Java version if multiple Java versions exist.

   sudo update-alternatives --config java

5. Select the OpenJDK 21 installation path.

Validation

1. Verify the installed Java version.

   java -version

2. Verify the Java compiler version.

   javac -version

3. Verify the Java installation path.

   which java

Expected Result

Example output:

openjdk version "21"

javac 21

The system uses JDK 21 as the active Java runtime.

Failure Impact

If Java 21 is not configured as the active version:

• NiFi 2.6 may fail to start.

• Unsupported JVM errors may appear in startup logs.

Uninstall Java 17 Version

Before uninstalling JDK 17, back up the existing Java certificate store (cacerts) if any connector certificates were previously imported into the Java truststore.

Back Up the Java Certificate Store

Run the following command to create a backup of the existing cacerts file:

cp /usr/lib/jvm/java-17-openjdk-amd64/jre/lib/security/cacerts \
/home/ubuntu/cacertsbackup

Purpose

Preserve custom certificates required by connectors and secure connections after the Java upgrade.

Validation

Verify that the backup file exists:

ls -l /home/ubuntu/cacertsbackup

Configure the Active Java Version

1. After installing JDK 21, update the active Java version using the alternatives configuration.

   sudo update-alternatives --config java

   Sample Reference Screenshot:

   
2. Select the JDK 21 installation path from the available options.

Validation

Verify the active Java version:

java -version

Expected Result

openjdk version "21"

Optional Cleanup

After validating that NiFi 2.6 starts successfully and all connector validations pass, remove JDK 17 from the server if it is no longer required.

Failure Impact

If the cacerts file is not backed up, custom connector certificates may need to be re-imported after the Java upgrade.

NiFi Upgrade Procedure (1.28.1 → 2.6)

Create a New NiFi Client Directory

Create a separate installation directory for the upgraded Bridge Client.

Purpose

Maintains the existing NiFi installation for rollback and prevents accidental modifications to the current environment.

Procedure

1. Navigate to the Bridge Client installation location.

   cd /home/ubuntu/nifi_client

2. Create a new directory for NiFi 2.6.

   mkdir nifi_2.6_client

3. Verify that the directory has been created.

   ls -ld nifi_2.6_client

4. Confirm that sufficient disk space is available.

   df -h

Validation

Verify:

• The directory exists.

• The directory owner and permissions are correct.

• Sufficient free disk space is available for installation.

Expected Result

Example output:

drwxr-xr-x ubuntu ubuntu nifi_2.6_client

The new installation directory is available and ready for the Bridge Client installation.

Rollback

The original NiFi installation remains unchanged and can be restored quickly if validation fails after the upgrade.

Download NiFi 2.6 Installer JAR

1. Download the latest Bridge Client installer JAR file on the Bridge Client VM using the wget command or copy the installer package to the server.

2. Before running the installer, collect the required values from the existing:

   <NiFi Installation>/conf/BridgeRegistration.properties

3. Run the installer.

   java -jar path_to_jar.jar

   Sample Reference Screenshot:

   
4. When prompted, press 1 and then press Enter to confirm the installation. Sample Reference Screenshot:

   

   Follow this step for any similar confirmation prompts displayed during the installation process.

5. When prompted to select the installation path, provide the path of the directory created earlier for the new Bridge Client installation. Example:

   /home/ubuntu/nifi_2.6_client

   Sample Reference Screenshot:

   
6. The default installation path is:

   /usr/local/ovaledge_bridge

7. Press 1 and then press Enter to confirm the installation path. Sample Reference Screenshot:

   
8. Enter the Security Code from the existing BridgeRegistration.properties file. Sample Reference Screenshot:

   

   Important: Use the same Security Code configured in the existing Bridge Client.

9. Enter the same IP Address from the existing BridgeRegistration.properties file. Sample Reference Screenshot:

   
10. Enter the Bridge Name exactly as configured in the existing BridgeRegistration.properties file. Sample Reference Screenshot:

    
11. Enter the Cloud Server URL provided by the OvalEdge team. Sample Reference Screenshot:

    
12. For the Certificates Path, enter the location of the Bridge Secure Connectivity Pack (ZIP file) copied to the Bridge Client VM. Sample Reference Screenshot:

    
13. For the Bridge Temp Path, enter the existing temporary directory path configured on the server. Sample Reference Screenshot:

    
14. Enter the User Name and Email Address from the existing BridgeRegistration.properties file. Sample Reference Screenshot:

    
15. When prompted for Is askEdgi, enter one of the following values:

    1. Enable askEdgi.

       true

       or

    2. Do not enable askEdgi.

       false

       Sample Reference Screenshot:

       
16. Press 1 and then press Enter to continue. Sample Reference Screenshot:

    
17. Press 1 and then press Enter again to proceed with the installation. Sample Reference Screenshot:

    
18. When prompted for confirmation, enter:

    Y

    and press Enter.

19. When prompted, provide the configuration file path enclosed in square brackets ([]).

20. Wait for the installation process to complete.

    Sample Reference Screenshot:

    

Validation

Verify that the following messages are displayed:

Installation was successful

Bridge software installed successfully

Expected Result

The NiFi 2.6 Bridge Client has been successfully installed in the specified installation directory and is ready for post-installation configuration.

Download and Run the Bridge Installer

1. Place the latest Bridge installer JAR in the bridge_artifacts directory.

2. Run:

   java -jar <bridge_installer>.jar

Configure the Bridge Installation

1. Run the Bridge installer.

   java -jar <bridge_installer>.jar

2. When prompted, provide the Bridge registration details from the existing BridgeRegistration.properties file.

3. Specify the newly created installation directory. Example:

   /home/ubuntu/nifi_2.6_client

4. Complete the installation wizard.

Validation

Verify the installer completes without errors.

Expected Result

The installer displays:

Bridge software installed successfully

Update Bridge Configuration Files

Copy Required Files

1. Copy the existing Bridge NAR file to the NiFi 2.6 lib directory.

   bridge-oe-<version>.nar

2. Copy the SAP library file to the NiFi 2.6 lib directory.

   sapjco3.jar

Verify bootstrap.conf

1. Open:

   conf/bootstrap.conf

2. Verify that the existing Bridge registration values are preserved.

3. Verify that the JVM arguments and heap settings match those of the previous Bridge installation.

Validation

Verify:

• Required NAR files exist.

• SAP JCo library exists.

• Bridge registration values are correct.

• JVM settings match the existing environment.

Update nifi.properties

1. Open:

   conf/nifi.properties

2. Locate the following properties:

   nifi.flow.configuration.file=./conf/flow.xml.gz
   nifi.flow.configuration.json.file=./conf/flow.json.gz

3. Update the properties as shown below:

   nifi.flow.configuration.file=./conf/flow.json.gz
   #nifi.flow.configuration.json.file=./conf/flow.json.gz

   Sample Reference Screenshot:

   
4. Save the file.

Validation

Verify the updated values are saved successfully.

Expected Result

NiFi is configured to use the flow.json.gz file required by NiFi 2.6.

Restart NiFi

1. Navigate to the NiFi installation directory. Example:

   cd /home/ubuntu/nifi_2.6_client

2. Start the NiFi service.

   ./bin/nifi.sh start

3. Start the NiFi service.

   ./bin/nifi.sh status

   or

   sudo systemctl status nifi

Validation

Verify:

• NiFi starts successfully.

• No startup exceptions appear in the logs.

• NiFi UI is accessible.

Expected Result

The NiFi service status displays as running, and the NiFi UI opens successfully.

Validate Bridge Status in the OvalEdge UI

1. Verify:

   1. Connected

   2. Running

Expected Result

Bridge status displays:

Connected
Running

Validate Connector Connectivity

Validate:

• Connector connection status

• Metadata crawling

• Lineage extraction

• Scheduler execution

• Profiling execution

• SAP connector communication

• Bridge response time

Expected Result

All connectors execute successfully without Bridge communication failures.

Rollback Procedure

Perform rollback if:

• NiFi fails to start

• Connectors fail consistently

• Bridge communication fails

• ECS task deployment fails

• Processor validation fails

• Metadata crawling stops unexpectedly

Rollback Steps

1. Stop the upgraded NiFi service.

2. Restore the backed-up nificonf directory.

3. Restore the previous ECS task definition or Bridge installation.

4. Restore the previous Java configuration if required.

5. Restart the original NiFi version.

Validation

Verify:

• Original flows are visible.

• Bridge status is healthy.

• Connectors execute successfully.

Post-Upgrade Verification Checklist

Validation Item	Expected Result
NiFi UI Accessibility	Accessible
Bridge Status	Connected
InvokeHTTP Processor	Running
Connector Validation	Successful
Metadata Crawling	Successful
Lineage Generation	Successful
Scheduler Execution	Successful
SAP Communication	Successful
Application Logs	No Critical Errors

Known Limitations

• Validate existing custom processors for compatibility with NiFi 2.6 before deployment.

• Verify third-party connector library compatibility with NiFi 2.6 before upgrading.

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