Apache Kafka Review Cluster and Topic Capacity

arazzo: 1.0.1
info:
  title: Apache Kafka Review Cluster and Topic Capacity
  summary: Walk a cluster from brokers to topics to the partition and replica layout of one topic.
  description: >-
    A read-only audit that answers whether a topic's partitioning and
    replication actually match the cluster it runs on. It reads the cluster and
    its brokers to establish how many are available, inventories the topics,
    then drills into one topic and its partitions to see the leader and replica
    placement per partition. Reviewing replica placement against the broker list
    is how under-replicated partitions and leader skew get caught before a
    broker loss turns them into an outage. Every step spells out its request
    inline so the flow can be read and executed without opening the underlying
    OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: kafkaRestProxyApi
  url: ../openapi/kafka-rest-proxy.yml
  type: openapi
workflows:
- workflowId: review-topic-capacity
  summary: Audit a topic's partition and replica layout against the cluster's brokers.
  description: >-
    Reads cluster, brokers, topic inventory, and per-partition replica placement
    for a single topic so capacity and durability can be assessed together.
  inputs:
    type: object
    required:
    - clusterId
    - topicName
    properties:
      clusterId:
        type: string
        description: The Kafka cluster id to audit.
      topicName:
        type: string
        description: The topic to drill into for partition and replica detail.
  steps:
  - stepId: readCluster
    description: >-
      Read the cluster to confirm it exists and to capture the controller
      reference that anchors the rest of the audit.
    operationId: getCluster
    parameters:
    - name: cluster_id
      in: path
      value: $inputs.clusterId
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      clusterId: $response.body#/cluster_id
      controller: $response.body#/controller
  - stepId: listBrokers
    description: >-
      List the brokers in the cluster. The broker count is the hard ceiling on
      any topic's replication factor and the baseline for judging replica
      spread.
    operationId: listBrokers
    parameters:
    - name: cluster_id
      in: path
      value: $steps.readCluster.outputs.clusterId
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      brokers: $response.body#/data
  - stepId: listTopics
    description: >-
      Inventory the cluster's topics, giving the audit the full picture of what
      is deployed before narrowing to one topic.
    operationId: listTopics
    parameters:
    - name: cluster_id
      in: path
      value: $steps.readCluster.outputs.clusterId
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      topics: $response.body#/data
  - stepId: readTopic
    description: >-
      Read the target topic's declared partition count and replication factor,
      which is what the audit compares against the broker list.
    operationId: getTopic
    parameters:
    - name: cluster_id
      in: path
      value: $steps.readCluster.outputs.clusterId
    - name: topic_name
      in: path
      value: $inputs.topicName
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      partitionsCount: $response.body#/partitions_count
      replicationFactor: $response.body#/replication_factor
      isInternal: $response.body#/is_internal
  - stepId: readPartitions
    description: >-
      Read the per-partition detail, exposing the leader and replica set for
      each partition. This is where leader skew and under-replication become
      visible.
    operationId: listPartitions
    parameters:
    - name: cluster_id
      in: path
      value: $steps.readCluster.outputs.clusterId
    - name: topic_name
      in: path
      value: $inputs.topicName
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      partitions: $response.body#/data
  outputs:
    brokers: $steps.listBrokers.outputs.brokers
    topics: $steps.listTopics.outputs.topics
    partitionsCount: $steps.readTopic.outputs.partitionsCount
    replicationFactor: $steps.readTopic.outputs.replicationFactor
    partitions: $steps.readPartitions.outputs.partitions