Apache ZooKeeper Monitoring API

openapi: 3.1.0
info:
  title: Apache ZooKeeper Admin Server Cluster Monitoring API
  description: The ZooKeeper Admin Server provides an HTTP interface for monitoring and management commands. It exposes four-letter-word equivalent commands as REST endpoints for cluster monitoring, configuration, and diagnostics.
  version: 3.9.0
  contact:
    name: Apache ZooKeeper
    url: https://zookeeper.apache.org/
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0
servers:
- url: http://localhost:8080/commands
  description: Local ZooKeeper Admin Server
- url: http://{zk_host}:{port}/commands
  description: Custom ZooKeeper Admin Server
  variables:
    zk_host:
      default: localhost
    port:
      default: '8080'
tags:
- name: Monitoring
  description: Server statistics and metrics
paths:
  /cons:
    get:
      operationId: getConnections
      summary: Apache ZooKeeper List Client Connections
      description: Returns information about all client connections. Equivalent to the 'cons' four-letter-word command.
      tags:
      - Monitoring
      responses:
        '200':
          description: Client connections information
          content:
            application/json:
              schema:
                type: object
                properties:
                  connections:
                    type: array
                    items:
                      type: object
                      properties:
                        remote_address:
                          type: string
                        interest_ops:
                          type: integer
                        outstanding_requests:
                          type: integer
                        packets_received:
                          type: integer
                        packets_sent:
                          type: integer
                        session_id:
                          type: string
                        session_timeout:
                          type: integer
                        last_operation:
                          type: string
                        last_latency:
                          type: integer
                        min_latency:
                          type: integer
                        avg_latency:
                          type: number
                        max_latency:
                          type: integer
                        last_response_timestamp:
                          type: integer
                  command:
                    type: string
                  error:
                    type: string
                    nullable: true
              examples:
                GetConnections200Example:
                  summary: Default getConnections 200 response
                  x-microcks-default: true
                  value: {}
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /crst:
    get:
      operationId: resetConnectionStats
      summary: Apache ZooKeeper Reset Connection Statistics
      description: Resets all connection statistics. Equivalent to the 'crst' command.
      tags:
      - Monitoring
      responses:
        '200':
          description: Statistics reset
          content:
            application/json:
              schema:
                type: object
                properties:
                  command:
                    type: string
                  error:
                    type: string
                    nullable: true
              examples:
                ResetConnectionStats200Example:
                  summary: Default resetConnectionStats 200 response
                  x-microcks-default: true
                  value: {}
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /dump:
    get:
      operationId: getDump
      summary: Apache ZooKeeper List Sessions and Ephemeral Nodes
      description: Lists the outstanding sessions and ephemeral nodes. Equivalent to the 'dump' four-letter-word command.
      tags:
      - Monitoring
      responses:
        '200':
          description: Session and ephemeral node information
          content:
            application/json:
              schema:
                type: object
                properties:
                  sessions:
                    type: array
                    items:
                      type: object
                      properties:
                        session_id:
                          type: string
                        timeout:
                          type: integer
                        ephemeral_nodes:
                          type: array
                          items:
                            type: string
                  command:
                    type: string
                  error:
                    type: string
                    nullable: true
              examples:
                GetDump200Example:
                  summary: Default getDump 200 response
                  x-microcks-default: true
                  value: {}
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /stat:
    get:
      operationId: getServerStats
      summary: Apache ZooKeeper Get Server Statistics
      description: Lists brief details for the server and connected clients. Equivalent to the 'stat' four-letter-word command.
      tags:
      - Monitoring
      responses:
        '200':
          description: Server statistics
          content:
            application/json:
              schema:
                type: object
                properties:
                  version:
                    type: string
                  read_only:
                    type: boolean
                  server_state:
                    type: string
                    enum:
                    - leader
                    - follower
                    - standalone
                    - observer
                  znode_count:
                    type: integer
                  packet_sent_count:
                    type: integer
                  packet_received_count:
                    type: integer
                  min_latency:
                    type: integer
                  avg_latency:
                    type: number
                  max_latency:
                    type: integer
                  num_alive_connections:
                    type: integer
                  outstanding_requests:
                    type: integer
                  approximate_data_size:
                    type: integer
                  open_file_descriptor_count:
                    type: integer
                  max_file_descriptor_count:
                    type: integer
                  last_client_response_timestamp:
                    type: integer
                  connections:
                    type: array
                    items:
                      type: object
                  command:
                    type: string
                  error:
                    type: string
                    nullable: true
              examples:
                GetServerStats200Example:
                  summary: Default getServerStats 200 response
                  x-microcks-default: true
                  value: {}
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /srvr:
    get:
      operationId: getServerInfo
      summary: Apache ZooKeeper Get Full Server Details
      description: Lists full details for the server. Equivalent to the 'srvr' four-letter-word command.
      tags:
      - Monitoring
      responses:
        '200':
          description: Full server details
          content:
            application/json:
              schema:
                type: object
                properties:
                  version:
                    type: string
                  read_only:
                    type: boolean
                  server_state:
                    type: string
                  znode_count:
                    type: integer
                  approximate_data_size:
                    type: integer
                  max_latency:
                    type: integer
                  min_latency:
                    type: integer
                  avg_latency:
                    type: number
                  packet_sent_count:
                    type: integer
                  packet_received_count:
                    type: integer
                  num_alive_connections:
                    type: integer
                  outstanding_requests:
                    type: integer
                  server_id:
                    type: integer
                  proposal_sizes:
                    type: string
                  command:
                    type: string
                  error:
                    type: string
                    nullable: true
              examples:
                GetServerInfo200Example:
                  summary: Default getServerInfo 200 response
                  x-microcks-default: true
                  value: {}
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /srst:
    get:
      operationId: resetStats
      summary: Apache ZooKeeper Reset Server Statistics
      description: Resets server statistics. Equivalent to the 'srst' command.
      tags:
      - Monitoring
      responses:
        '200':
          description: Statistics reset
          content:
            application/json:
              schema:
                type: object
                properties:
                  command:
                    type: string
                  error:
                    type: string
                    nullable: true
              examples:
                ResetStats200Example:
                  summary: Default resetStats 200 response
                  x-microcks-default: true
                  value: {}
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /mntr:
    get:
      operationId: getMonitorMetrics
      summary: Apache ZooKeeper Get Monitoring Metrics
      description: Returns a list of variables for monitoring the health of the cluster. Equivalent to the 'mntr' four-letter-word command.
      tags:
      - Monitoring
      responses:
        '200':
          description: Monitoring metrics
          content:
            application/json:
              schema:
                type: object
                properties:
                  zk_version:
                    type: string
                  zk_avg_latency:
                    type: number
                  zk_max_latency:
                    type: integer
                  zk_min_latency:
                    type: integer
                  zk_packets_received:
                    type: integer
                  zk_packets_sent:
                    type: integer
                  zk_num_alive_connections:
                    type: integer
                  zk_outstanding_requests:
                    type: integer
                  zk_server_state:
                    type: string
                  zk_znode_count:
                    type: integer
                  zk_watch_count:
                    type: integer
                  zk_ephemerals_count:
                    type: integer
                  zk_approximate_data_size:
                    type: integer
                  zk_open_file_descriptor_count:
                    type: integer
                  zk_max_file_descriptor_count:
                    type: integer
                  zk_followers:
                    type: integer
                    description: Leader only
                  zk_synced_followers:
                    type: integer
                    description: Leader only
                  zk_pending_syncs:
                    type: integer
                    description: Leader only
                  zk_last_proposal_size:
                    type: integer
                  zk_max_proposal_size:
                    type: integer
                  zk_min_proposal_size:
                    type: integer
                  command:
                    type: string
                  error:
                    type: string
                    nullable: true
              examples:
                GetMonitorMetrics200Example:
                  summary: Default getMonitorMetrics 200 response
                  x-microcks-default: true
                  value: {}
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /hash:
    get:
      operationId: getHash
      summary: Apache ZooKeeper Get Data Tree Digest
      description: Returns the digest of the data tree.
      tags:
      - Monitoring
      responses:
        '200':
          description: Data tree digest
          content:
            application/json:
              schema:
                type: object
                properties:
                  digests:
                    type: object
                  command:
                    type: string
                  error:
                    type: string
                    nullable: true
              examples:
                GetHash200Example:
                  summary: Default getHash 200 response
                  x-microcks-default: true
                  value: {}
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /last_snapshot:
    get:
      operationId: getLastSnapshot
      summary: Apache ZooKeeper Get Last Snapshot Info
      description: Returns information about the last snapshot taken.
      tags:
      - Monitoring
      responses:
        '200':
          description: Last snapshot information
          content:
            application/json:
              schema:
                type: object
                properties:
                  last_snapshot_zxid:
                    type: string
                  last_snapshot_size:
                    type: integer
                  command:
                    type: string
                  error:
                    type: string
                    nullable: true
              examples:
                GetLastSnapshot200Example:
                  summary: Default getLastSnapshot 200 response
                  x-microcks-default: true
                  value: {}
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK