New VisualVM and CLI Releases Available

We’re thrilled to announce the release of the latest updates for the Coherence VisualVM Plugin and the Coherence command-line interface (CLI).

Both these tools now support the latest Coherence Community Edition (CE) version 24.03, as well as many new features to enhance the management and monitoring of clusters.

Whats new VisualVM Plugin 1.7.0

Dive deeper into your Coherence clusters with the new tracer probes feature. Integrated with the VisualVM Tracer framework, it allows you to monitor specific Coherence metrics with ease, offering insights never before accessible. Export these metrics as CSV files for comprehensive analysis, optimizing your cluster’s performance with data-driven decisions.

Key Probe Highlights

• Cluster Overview: Get a snapshot of your cluster’s health, including member status, memory usage, and more.
• Service Insights: Drill down into service and cache operations for detailed performance metrics.
• Proxy and Persistence Metrics: Monitor connection details, persistence data, and ensure smooth operation across your cluster.

Support has also been added for displaying information regarding View Caches when you select a cache in the Caches tab.

See the release notes for the VisualVM Plugin for more information.

Coherence CLI Version 1.6.0 Highlights

We’ve extended the features of the Coherence CLI. Some key changes are:

• View Cache Support: Navigate and manage your view caches more effectively with new commands, enhancing your operational capabilities.
• Enhanced Management Commands: Leverage additional commands like cohctl get cache-partitions and cohctl describe view-caches for a more granular control over your Coherence clusters. (**)

Note: (**) These commands are only initially supported in CE 24.03+, but will be available in future patches for other CE and commercial versions.

See the release notes for the CLI for more information.

Conclusion

The latest releases of the VisualVM Plugin and CLI mark a significant advancement in the management and monitoring capabilities available for Coherence clusters. For detailed information and to get started with these powerful tools, visit our open source repositories:

• Coherence VisualVM Plugin
• Coherence CLI

New Episode – “5 Minutes of Coherence” – Cache Store

We have just released a new episode of “5 Minutes of Coherence”, this time focussing on Cache stores.

Episode 2 – Coherence Cache Stores

Keep an eye out for the next episode coming soon. There are also plenty of resources on the Coherence YouTube channel to keep you busy in the meantime.

Enjoy

Using Coherence to manage HTTP sessions in Go

Happy new year, hope it was a safe and happy one!

We have just published an article explaining how your Go applications can now use Coherence as an HTTP session store via integration with the very popular “Express inspired web framework” Fiber. (https://github.com/gofiber/fiber)

The article and full code examples are available on our Medium Blog.

Enjoy

Coherence CLI 1.5.2 Released

We are pleased to announce that the latest patch of the Coherence Command Line Interface (CLI) has been released. This new release comes with a few bug fixes and some great new features to align with our latest Coherence CE and commercial releases.

New Features/ Changes

• Added cohctl get service-distributions to show scheduled partition distributions
• Added settings option to start jfr command to allow to change the settings file
• Added evictions to cohctl get caches and cohctl describe caches commands
• Update topics commands to display channel ownership
• Changed the default CE version to 22.06.6 and support CE 23.09

The following features are available with CE 23.09, 22.06.6 and the latest commercial patch 14.1.1.2206.6:

• Added cohctl get service-description to show service description and members
• Added cohctl get member-description to show member description
• Added cohctl get cluster-description to show the cluster description and members
• Added cohctl get cluster-config to display the operational config for a cluster. Only available with most recent versions of Coherence clusters

Bug Fixes/Enhancement

• Fixed an issue with connecting using VisualVM to a cluster created with the CLI. You must remove an existing cluster and re-create a cluster for this to take effect
• Fixed an issue where describe service would fail with only 1 node
• Bump golang.org/x/net from 0.8.0 to 0.17.0

Installing

See here for installations instructions.

Upgrading

If you already have the CLI installed, you can run cohctl version -u to see if you have the latest version.

More Information

For more information on the Coherence CLI see the repository on GitHub – https://github.com/oracle/coherence-cli

Enjoy!

Presenting on Coherence at AUSOUG Connect 2023 in Melbourne

Looking forward to presenting at AUSOUG Connect 2023 in Melbourne on Wednesday 15th November.

It should be a great conference with many presentations on various topics from Development, Database and Cloud Applications. See https://www.ausoug.org.au/connect-2023-melbourne/ for details and how to register.

My session is entitled “Managing state in Microservices using Oracle Coherence on Kubernetes“, abstract is below:

It can be “easy” to scale stateful microservices, but scaling their data stores can be a challenge and this is usually a bottleneck in many systems. In this presentation, Tim will explain how Coherence can provide a scalable, reliable, and performant data store for microservices written in Python, Go, NodeJS and Java.

He will also demonstrate a Microservice application deployed on Oracle’s Container Engine for Kubernetes (OKE) where the state is shared across multiple languages using Coherence.

Look forward to attending and seeing some familiar Melbourne faces!

New Short Video Series on Coherence

We have just released the first video in a new series “Five Minutes of Coherence”.

These videos are short videos quickly explaining or overviewing a specific Coherence feature or characteristic. Episode 1 explains at a high-level the different Coherence cache types and their usage and can be viewed on our YouTube Channel.

We will be releasing these regularly on various Coherence topics, so if you have a topic your would like us to cover, leave a comment.

Enjoy!

Coherence Go Client (v1.0.0) now GA

We are pleased to announce that the Coherence Go Client (v1.0.0) is now GA!

What is the Coherence-Go Client?

• The Coherence Go Client allows Go applications to act as cache clients to a Coherence Cluster using gRPC for the network transport.
• Supported on Coherence CE 22.06.4+ or Coherence 14.1.1.2206.4+ Commercial edition with a configured gRPCProxy. (Can get started using the latest coherence docker image)
• Go 1.19+ required – API fully supports generics.

Features
Familiar Map-like interface for manipulating cache entries including but not limited to:

• Put, PutWithExpiry, PutIfAbsent, PutAll, Get, GetAll, Remove, Clear, GetOrDefault, Replace, ReplaceMapping, Size, IsEmpty, ContainsKey, ContainsValue, ContainsEntry
• Cluster-side querying, aggregation and filtering of map entries
• Cluster-side manipulation of map entries using EntryProcessors
• Registration of listeners to be notified of: mutations such as insert, update and delete on Maps, map lifecycle events such as truncated, released or destroyed and session lifecycle events such as connected, disconnected, reconnected and closed
• Support for storing Go structs as JSON as well as the ability to serialize to Java objects on the server for access from other Coherence language API’s

More Information

• Visit and ⭐ the Coherence Go Client repo on GitHub
• Explore/ Run the comprehensive examples
• Visit the GoDoc page on pkg.go.dev
• Read the FAQ

Coherence Go Client – Release Candidate out now!

We are excited to announce that Coherence Go Client 1.0.0-RC1 is available now on GitHub!

The Coherence Go Client allows Go applications to act as cache clients to a Coherence Cluster using gRPC for the network transport and is available to run against Coherence Community Edition (CE) 22.06.4+ and commercial editions 14.1.1.2206.4+.

If you would like to know more please see the following:

• Medium article introducing the Go client
• YouTube video explaining the client in more detail including a demo
• GoDoc on pkg.go.dev

Keep an eye for more resources on the Go client as well as upcoming releases of other language clients very soon!

Enjoy!

Updated VisualVM and Coherence CLI Tools

We are happy to announce we have just released updated versions of both the Coherence CLI and Coherence VisualVM Plugin.

Both tools now have full support for Coherence CE versions 23.03, 22.06.4 plus commercial versions 14.1.1.2206.4 as well as the ability to manage and monitor Coherence Topics, Subscribers and Subscriber Groups.

Release Highlights

Coherence VisualVM 1.6.0

• Added the ability to discover Coherence Clusters with Management over REST enabled via adding a host by right-clicking on the host and selecting Discover Coherence Clusters
• Added new Topics tab with support for new Topics MBeans in 14.1.1.2206.4+,22.06.4+, and 23.03+
• Added the ability to right-click on a proxy server and display the connections
• Added the ability to pause the refreshing of the Cluster Snapshot tab and copy the HTML contents to the clipboard
• Added the ability for an immediate refresh of data when a selection is made for a master-detail table

Coherence CLI 1.5.0

• Added commands to display topics, subscribers and subscriber groups. See here for more information
• Added cohctl get network-stats to show all member network statistic for a cluster
• Added cohctl get p2p-stats to show point-to-point network statistics for a specific member
• Added cohctl get service-storage to show partition storage for all services
• Added cohctl get cache-stores to show cache store information for a cache

For more information, please see the following:

• Coherence VisualVM 1.6.0 Release Notes
• Coherence CLI 1.5.0 Release Notes
• Medium Article on CLI Release
• Coherence Topics Documentation

Medium Article – Deep Dive: Aggregators

Happy new year to all, and with that, one of my favourite things about the Australian Summer, T20 Cricket, is over. At least we finished on a high with the “Perth Scorchers” winning the final at their home stadium! (shown below)

From a Coherence perspective, we start off this year with Gunnar Hillert, from the Coherence development team having just published a great article providing a deep dive into the world of Coherence Aggregators.

This article builds upon my previous article on Queries and shows the awesome power of running aggregators with Coherence. Gunnar explains how they work and includes examples of out of the box aggregators as well as how to create custom aggregators.

See the Coherence Blog on Medium for the full article.

Enjoy!