# What’s New in OpenNMS Meridian 2022

## System Requirements

• Java 11: OpenNMS Meridian 2022 runs on JDK 11.

• PostgreSQL 10 or higher: Meridian 2022 requires any supported version of PostgreSQL from 10 up to (and including) 14.

## Breaking Changes

### Running as Non-Root

By default, OpenNMS now runs as the `opennms` user rather than `root`.

 If you are upgrading from a version of OpenNMS Meridian older than 2022, you will have to fix the ownership of your files.

#### Fixing Permissions and Ownership

Since many OpenNMS instances are very large with thousands or even millions of RRD and similar data files in `$OPENNMS_HOME/share`, we decided not to change ownership automatically upon package upgrade. The OpenNMS installer will detect if you need to fix the ownership of your files and warn you to run the script to fix permissions (`$OPENNMS_HOME/bin/fix-permissions`) in this case.

### Kafka RPC Single Topic

This release changes the Kafka RPC default configuration to publish on a single target. If you are using Minions, both the Minion and OpenNMS need to be updated.

Make sure that Kafka lag on Sink topics is minimal before upgrading, or there may be loss of those sink messages.

Also, the Twin API has replaced the OpenNMS REST API for synchronizing Trapd configuration updates. Additional settings are needed on both Minion and Meridian to enable Twin when not using the ActiveMQ message broker.

Refer to the deployment section in the documentation for details.

 In Meridian 2022, we consolidated IPC features on Minion. This groups all IPC (Sink/RPC/Twin) features of JMS into one feature as `openms-core-ipc-jms`. Similarly for Kafka and gRPC. When using Kafka or gRPC, you need to disable `opennms-core-ipc-jms` instead of disabling individual features such as `opennms-core-ipc-sink-camel`.

### Situation Feedback Persistence Configuration

The configuration file `etc/org.opennms.features.situation-feedback.persistence.elastic.cfg` has been renamed to `etc/org.opennms.features.situationfeedback.persistence.elastic.cfg` (i.e. the minus sign is removed from the filename). This fixes a race condition on startup when using ALEC.

### SQS Minion IPC Support Dropped

Support for Amazon SQS for Minion communication has been removed. We recommend to use Kafka instead for use cases that require horizontal scaling of Minion communication.

### Time Series Integration Layer Changes

The Time Series integration layer has gone through a number of big improvements to reduce the complexity and cardinality of metadata and tags.

• Time series plugins need to be compatible with OIA 0.6.x.

• Resource-level string attributes are now also stored via the plugin in the respective time series database. The `timeseries_meta` table which previously stored this metadata has been removed. There is no migration; string values are generally updated on the next poll.

## New Features and Improvements

### Flows and streaming analytics

Streaming analytics and flow processing have gone through a number of major enhancements.

• A huge number of perfomance improvements have been made since Meridian 2021.

• Flow aggregation now supports DSCP ToS/QoS fields.

• Flow metadata has been tuned and redundancy has been removed, resulting in less data being stored per update.

• Elasticsearch persistence has been improved to support batching updates.

• The flow classification engine has been almost entirely rewritten to be considerably more performant when processing large rulesets.

• Support has been added for persisting flows to Cortex.

### Minion

The Minion continues to receive improvements in performance and features, most notably the addition of a new API (the "Twin API"), which pushes configuration to Minion over RPC, reducing the amount of data that needs to be passed over the wire.

The first subsystem to adopt this new API is SNMPv3 auth data, so the Minion no longer needs to make a REST call to the OpenNMS core. Over time, all configuration information will be migrated to this new API.

• The Minion confd file has been updated with a bunch of documentation describing various options.

• Support has been added for exporting a number of JMX metrics through Prometheus for out-of-band monitoring of the Minion.

• The Minion now has support for querying its health through REST.

### Provisioning

You can use the GeoIP Provisioning Adapter to enrich a node’s asset data with location information. It uses the GeoIP2 Databases from MaxMind to look up longitude/latitude values for a given IP address.

### REST API

• Initial support for enumerating REST API endpoints has been added, using Swagger. A link is available in the "help" section of the web UI.

• Elastic flow queries return additional data for DSCP QoS/ToS data.

• RTC data now includes an additional boolean field for service up/down status.

### Documentation

• A ton of work has gone into cleaning up, rearranging, and standardizing terms in the documentation.

• A bunch of additional REST APIs are now documented through OpenAPI.

## Important Internal Changes

• Kafka components have been updated to version 2.8.0

• Our embedded Karaf has been updated to version 4.3.2

## Other Improvements

Since Meridian 2022 is based on Horizon 29, it contains all the fixes and updates that have occurred since Meridian 2021 was created from the Horizon 27.1 codebase.

For a more complete list of major changes included in this release, see the "What’s New" documentation: