Overview
In the configuration, our applications behave as consumers that communicate with each other to complete processes. They use a JSON format to send and receive messages. Consumer groups are used to scale our applications and share the same identifier. For example, when two model controllers coexist, each one is a consumer and they both belong to the same consumer group.
A topic is the data structure Kafka uses to store and distribute messages. Topics organize messages in partitions. Consumers are attached to different topics. When a topic receives a message, it sends it to a consumer group. Just one of the group’s consumers receives the message. The consumer array contains all connections receiving messages from a topic. Learn more about topic configuration here.
The groups object
{
"teamState": "",
"teamId": "",
"consumer": []
}
Parameter | Type | Description |
---|---|---|
teamState | string | The team’s status. Values can be |
teamId | string | The team’s identifier. |
consumer | array | An array of consumers. |
The consumers object
{
"topicPartitions": [],
"consumerId": "",
"clientId": ""
}
Parameter | Type | Description |
---|---|---|
topicPartitions | array | An array of topic partition objects. |
consumerId | string | The consumer’s identifier. Applications may have a different consumers for each instance. |
clientId | string | The client application’s identifier. |
The topics object
{
"consumerApplication": "",
"producedBy": "",
"topic": "",
"description": "",
"data": {}
}
Parameter | Type | Description |
---|---|---|
consumerApplication | string | The application that consumes the topic’s messages. |
producedBy | string | The application that produces the topic’s messages. |
topic | string | The topic’s name. |
description | string | The consumer’s action after it receives the message. |
data | object | The team’s object. |
The topics partition object
{
"topic": "",
"partition": 0,
"byteSize": -1,
"offset": {}
}
Parameter | Type | Description |
---|---|---|
topic | string | The topic’s identifier. |
partition | number | The partition’s index number. |
byteSize | number | The disk space used by the partition in bytes. Its value is -1 if the partition has never used its disk space. |
offset | object | The offset object. |
The offset object
{
"currentOfConsumer": 44562,
"lastOfTopic": 44562,
"lag": 0
}
Parameter | Type | Description |
---|---|---|
currentOfConsumer | number | The last consumed message’s index. |
lastOfTopic | number | The last message index available in the partition. |
lag | number | The difference between the last consumed message’s index and the newest message’s index for a consumer in the topic. |