Tahu

Since Camel 4.8

Both producer and consumer are supported

The Tahu components adapt the Eclipse Tahu library for Camel. These components support creating Sparkplug Edge Nodes, Devices, and Host Applications as described by Eclipse Sparkplug using Sparkplug B payload encoding.

For more information regarding Sparkplug concepts and required behavior, consult the Sparkplug 3.0.0 Specification

Neither the use of the Eclipse Tahu library nor the Camel Tahu Components implies Sparkplug 3.0.0 specification compliance. While it should be possible to create Sparkplug 3.0.0-compliant applications using the Camel Tahu Components, no claims or guarantees are expressed or implied.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>{artifactid}</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

Tahu components

See the following for usage of each component:

Tahu Edge Node / Device

Sparkplug B Edge Node and Device support over MQTT using Eclipse Tahu

Tahu Host Application

Sparkplug B Host Application support over MQTT using Eclipse Tahu

URI format

Edge Nodes and Devices (Producers)

Edge Node and Device endpoints, where groupId, edgeNodeId, and deviceId are the Sparkplug Group, Edge Node, and Device IDs describing the Edge Node or Device.
tahu-edge://groupId/edgeNodeId[/deviceId]?options
Example: Edge Node Producer for Group 'Basic' and Edge Node 'EdgeNode' using MQTT Client ID 'EdgeClient1' connecting to Host Application 'BasicHostApp'
tahu-edge://Basic/EdgeNode?clientId=EdgeClient1&primaryHostId=BasicHostApp&deviceIds=D2,D3,D4
Example: Device Producers for Devices 'D2', 'D3', and 'D4' connected to Edge Node 'EdgeNode' in Group 'Basic', i.e. the Devices of the Edge Node in the example above
tahu-device://Basic/EdgeNode/D2
tahu-device://Basic/EdgeNode/D3
tahu-device://Basic/EdgeNode/D4

Host Applications (Consumers)

Host Application endpoints, where hostId is the Sparkplug Host Application ID
tahu-host://hostId?options
Example: Host Application Consumer for Host App 'BasicHostApp' using MQTT Client ID 'HostClient1'
tahu-host:BasicHostApp?clientId=HostClient1

Endpoints

Tahu component endpoints describe a Sparkplug Edge Node, Device, or Host Application. All Sparkplug specification requirements must be observed when defining the endpoint URIs, including allowed characters in names, uniqueness in IDs, etc. Device IDs can include additional hierarchy with '/' characters as allowed by the specification.

Tahu Edge Node and Device endpoints only allow Producers to be created. Tahu Host Application endpoints only allow Consumers to be created.

Usage

The Sparkplug 3.0.0 specification requires Sparkplug B MQTT message payloads to follow a Google Protobuf format with an specific structure and message order. Many of these requirements necessitate careful Tahu Component and Endpoint configurations.

Component Configuration

Tahu Component configuration is primarily composed of MQTT Server connection information. These properties may be configured on Endpoint URIs or the Tahu Component to cover all Endpoints created using that Component instance.

The servers property is a comma-separated list with the following syntax:

MqttServerName:[MqttClientId:](tcp|ssl)://hostname[:port],...

This gives a unique server name to each MQTT Server as well as its connection scheme (tcp or ssl), hostname, and optionally the port number. A connection-specific MQTT Client ID may also be assigned when connecting to this particular server. MQTT Client ID uniqueness requirements apply.

A common MQTT Client ID may also be configured through the clientId property and will apply to all MQTT Server connections NOT specifying a connection-specific MqttClientId in the servers list. Should neither the clientId nor the MqttClientId be set, a random MQTT Client ID will be generated prefaced by "Camel".

MQTT Client IDs are limited to 23 characters in MQTT v3.1. However, MQTT v3.1.1 increased that limit to 256 characters. When connecting to MQTT Servers only supporting v3.1, setting the checkClientIdLength flag to true will add a 23-character length check to ensure proper Client ID lengths. This is a configuration-time check and is not required to connect to MQTT v3.1 Servers.

MQTT Server authentication can be configured using the username and password properties. TLS configuration can also be configured by providing an SSLContextParameters instance or through the useGlobalSslContextParameters flag.

An MQTT connection keep alive timeout can be configured using keepAliveTimeout.

A delay can be added between Edge Node Rebirth publishing through the rebirthDebounceDelay property.

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