Goals

• Understanding the concepts of AMQ Online.
• Learning how to use AMQ Online.

1. AMQ Online Components

AMQ Online is a solution (Operator) to manage multiple components to provide the overall functionality of running self-service (Messaging as a Service) messaging platform on OpenShift.

• AMQ Broker:
• AMQ Broker is a full-featured, message-oriented middleware broker. It offers advanced addressing and queueing, fast message persistence, and high availability. AMQ Broker supports multiple protocols and operating environments, enabling you to use your existing assets.
• This is where all your brokers hosted, and it is responsible for persisting messages.
• AMQ Interconnect:
• AMQ Interconnect provides flexible routing of messages between AMQP-enabled endpoints, including clients, brokers, and standalone services. With a single connection into a network of AMQ Interconnect routers, a client can exchange messages with any other endpoint connected to the network.
• This is where all your routes are hosted (this will come later when explaining address).

• Keycloak:
• Open Source Identity and Access Management, which is used to host access control information for queues, topic, etc.

2. Understanding AMQ Online Custom Types

The installed AMQ Online defines new types (CRDs), which will be briefly explained.

2.1. AuthenticationService

AuthenticationService describes an authentication service instance used to authenticate massaging clients. This is simply your way to configure the Keycloak server itself.

2.2. AddressSpacePlan

Address SpacePlan describes the messaging resources available for address spaces (which will be explained later) using this plan (as an aggregate of AddressPlan), such as the available address plans and the amount of router and broker resources that can be used. Think of it as the main quota control. It knows how much hardware can be used by referring to infrastructure configuration. [IMPORTANT] It defines the infrastructure to be deployed, and as its name depicts "plan," it defines quota restrictions (in other words,, the maximum number of addresses).

2.3. AddressPlan

The Address Plan describes the messaging resources consumed by a particular address using this plan, such as what fraction of routers and brokers an address will use and other properties that should be set for multiple addresses.

2.4. Infrastructure Configuration

As the name suggests, it configures the hardware resource allocated to the components, such as CPU, memory, storage of console, broker, router, and some other specific config, too, of mainly two types:

2.4.1. StandardInfraConfig

This allow hosting the AMQ Brokers and AMQ Interconnect routes.

2.4.2. BrokeredInfraConfig

This allows hosting AMQ Brokers only.

2.4.3. Address Space

This is a group of addresses accessible through single connection.

2.4.4. Address

Defines semantics of address and has a set of properties:

• Available address types determined by the address space type
• Available plans determined by the address type

• Address Space — Refers back to AddressSpacePlan, which creates the AMQ Broker Pod and the AMQ Interconnect Pod based on the type (standard or brokered), and like them with Keycloak (AuthenticationService) as an authentication/authorization source and does the needed configuration.
• Address — The destinations that use the spinned pods from AddressSpace to configure broker or routers.
• Message User — Defines the authentication/authorization attributes (meaning which user can do what) for a specific destination (such as a queue or topic). It mainly writes the rules to Keycloak.

3. Understanding AMQ Online from Roles and Responsibilities Points of View

There are two main roles in AMQ Online:

3.1. Admins

Admin does the installation of the platform foundation on OpenShift. The admin installs all the basic elements that control the necessary brokers, routers, user console, monitoring tools and also takes care of setting up the authentication and authorization of who has access to the platform. We don’t always have unlimited computing resources for all users. Admin also has control over the resource limitation and creates different plans that can apply to accompany different users’ needs.

3.2. Developers / Application Owners / Tenants

Developers are the users of the platform, they will be creating "Address Space," and they will creating destinations by applying the plans on top of it. After the queue and topics are created, the tenants can create credentials maps (MessagingUser) to different access roles. They can also decide which account has access to the admin console and which account has consume/produce rights to any addresses (queues/ topics) in the Address Space. Please note:, Tenants will have no visibility to the queue or topics of other Address Space, unless specially specified. Once the address are created and config correctly, application will be able to use the credential to read/write to the messaging address.

So a typical workflow will be:

1. Admins install AMQ Online from Operator Hub or install it manually.
2. Admins will create needed objects in amq-online namespace
1. Define AuthenticationService(s)
2. Define StandardInfraConfig(s) Or BrokeredInfraConfig(s)
3. Define AddressSpacePlan
4. Define AddressPlan
3. Each Tenant will create needed objects in his own namespace.
1. Define AddressSpace
2. Define Address
3. Define MessageUser

4. Understanding the Difference between Standard and Brokered InfraConfig

Table 1. Supported Features Reference Table

Installing AMQ Online on OpenShift 4.x server

There are two ways for installing AMQ online.

1. Using the source files for RedHat portal.
2. Using the AMQ online operator from OperatorHub.
• For ease of use i created a oc cli script which effectively use OperatorHub for installation install-amq-online.sh.

JMS clients and libraries

There are multiple JMS Clients depending on the underlying Messaging Protocol (as shown in above table) each one has a set features and may also have some limitations.

• Messaging Protocol

1. AMQP: AMQP JMS client provides full AMQP 1.0 support and works with any AMQ server.
   AMQ AMQP JMS is a Java Message Service (JMS) 2.0 client for use in messaging applications that send and receive AMQP messages.

• Key features

1. JMS 1.1 and 2.0 compatible
2. SSL/TLS for secure communication
3. Flexible SASL authentication
4. Automatic reconnect and failover
5. Distributed tracing based on the OpenTracing standard
6. Ready for use with OSGi containers
7. Pure-Java implementation

• Procedure

1. Add the Red Hat repository to your Maven settings or POM file. For example configuration files, see Section B.1, “Using the online repository”.

<repository>
  <id>red-hat-ga</id>
  <url>https://maven.repository.redhat.com/ga</url>
</repository>

• Add the client dependency to your POM file.
  

• • • • The client library is now available in your Maven project.

• • • • for more info refer to https://access.redhat.com/documentation/en-us/red_hat_amq/7.5/html-single/using_the_amq_jms_client/index

1. OPENWIRE: OPENWIRE JMS CLIENT
   AMQ OpenWire JMS is a Java Message Service (JMS) 1.1 client for use in messaging applications that send and receive OpenWire messages. To support existing applications based on A-MQ 6

• Key features

1. JMS 1.1 compatible
2. SSL/TLS for secure communication
3. Automatic reconnect and failover
4. Distributed transactions (XA)
5. Pure-Java implementation

• Procedure

1. Add the Red Hat repository to your Maven settings or POM file. For example configuration files, see Section B.1, “Using the online repository”.
   
   

<repository>
  <id>red-hat-ga</id>
  <url>https://maven.repository.redhat.com/ga</url>
</repository>

1. Add the library dependency to your POM file.
   
   

<dependency>
  <groupId>org.apache.activemq</groupId>
  <artifactId>activemq-client</artifactId>
  <version>5.11.0.redhat-630329</version>
</dependency>

The client is now available in your Maven project.
for more info refer to https://access.redhat.com/documentation/en-us/red_hat_amq/7.5/html-single/using_the_amq_openwire_jms_client/index

1. CORE: AMQ Core Protocol JMS is a Java Message Service (JMS) 2.0 client for use in messaging applications that send and receive Artemis Core Protocol messages. Artemis core is a messaging system with its own API.

• Key features

1. JMS 1.1 and 2.0 compatible
2. SSL/TLS for secure communication
3. Automatic reconnect and failover
4. Distributed transactions (XA)
5. Pure-Java implementation

• Procedure

• Add the Red Hat repository to your Maven settings or POM file.

<repository>
  <id>red-hat-ga</id>
  <url>https://maven.repository.redhat.com/ga</url>
</repository>

• Add the library dependency to your POM file.

<dependency>
  <groupId>org.apache.activemq</groupId>
  <artifactId>artemis-jms-client</artifactId>
  <version>2.9.0.redhat-00002</version>
</dependency>

The client is now available in your Maven project.
for more info refer to https://access.redhat.com/documentation/en-us/red_hat_amq/7.5/html-single/using_the_amq_core_protocol_jms_client/index