Co Authored with Nicolas Frankel (Hazelcast Developer Advocate), this article is also available as a PDF.

The Hazelcast In-Memory Data Grid (IMDG) is an efficient method of storing data in a distributed way within the memory of the different processes of the cluster. Because it is distributed, searching the data locally requires 'moving' the data to your instance so it can be accessed, which is not overly efficient.  Hazelcast SQL allows distributed queries which perform the search where the data is, and then transfers only the results to your process. Since the Payara products already use Hazelcast IMDG, using the Hazelcast SQL capabilities is straightforward: just add the additional JAR library to start using it.

Introduction

The Apache Maven Cargo Plugin allows you to deploy your application to a Payara Server, running locally or remotely. Using Maven as a build tool is an easy way to immediately deploy the application during the build to a test or production server.

We have created a custom version of the Cargo Plugin which also supports the Deployment Group feature of the Payara Server.

One of the cornerstones of any modern Payara Platform architecture is the use of the Domain Data Grid. The Domain Data Grid allows multiple Payara Server or Payara Micro instances to join and form a robust cluster of interchangeable nodes that can share data between each other and grant High Availability and Failover capabilities to any applications deployed in the cluster. 

What happens when an application designed for a small user base needs to be scaled up and moved to the cloud?

It needs to live in a distributed environment: responding to an appropriate number of concurrent user requests per second and ensuring users find the application reliable. 

Though Jakarta EE and Eclipse MicroProfile can help with reliable clustering, there is no standard API in Jakarta EE that defines how clustering should work currently. This might change in the future, but in the meantime, this gap must be filled by DevOps engineers.

In this blog, we will cover 10 technical strategies to deal with clustering challenges when developing Jakarta EE and MicroProfile for cloud environments.

Hazelcast in the Payara Platform offers several ways to configure how instances cluster. One new way is by using DNS records.

Note: This blog post is an update to Creating a Simple Cluster, which was written for Payara Server 4.

Introduction

Continuing our introductory blog series, this blog will demonstrate how to set up a simple Hazelcast deployment group containing two instances. Deployment groups were introduced with Payara 5 to replace clusters. They provide a looser way of managing servers, allowing instances to cluster by sharing the same configuration whilst providing a single deployment target for all of them. See here to read more about Deployment Groups.

When it comes to clustering and distributed computing performance, some of the challenges you have to overcome involve cache invalidation and coordination. Fortunately, both Payara Server and Payara Micro come with EclipseLink, which supports cache coordination and invalidation out of the box. This blog will explain how to configure this feature for your Payara Data Grid.  We would also like to thank Sven Diedrichsen who is the community member that created the Hazelcast cache coordination.

Avanzando más nuestra serie de blogs de introducción, esta entrada mostrará como puedes escalar de forma dinámica tu cluster, y como Payara Server maneja la conmutación por fallas entre miembros del cluster.

See here for the original version in English language.

La conmutación por fallas es la habilidad de continuar proporcionando acceso a nuestro sitio web o aplicación en el caso de que un servidor falle. Es una parte importante de un servicio que goza de alta disponibilidad, cuyo objetivo es minimizar los tiempos de inactividad a lo largo de tu infraestructura de servicios.

In Payara Server 5 we will be introducing some major changes to the way clustering is working by creating the Domain Data Grid (see documentation for more info). The Domain Data Grid will be easier to use, more scalable, more flexible and ideally suited for cloud environments and cloud-native architectures. All Payara Server instances will join a single domain-wide data grid for sharing of in-memory data like web sessions, JCache, SSO and Stateful EJBs. 

Payara Micro supports Hazelcast out of the box, and can be used for clustering. This allows members in the cluster to distribute data between themselves, amongst other things. By default, Hazelcast comes with multiple ways to discover other members in the same network. A multicast discovery strategy is commonly used for this purpose; a multicast request is sent to all members in a network and the members respond with their IP addresses. Another strategy must be employed if a member cannot or does not wish to provide their IP address.