openapi: 3.2.0
info:
  version: '9.0'
  title: NGINX Plus REST HTTP Upstreams API
  description: NGINX Plus REST API provides access to NGINX Plus status information, on-the-fly configuration of upstream servers and key-value pairs management for http and stream.
servers:
- url: /api/9
tags:
- name: HTTP Upstreams
paths:
  /http/upstreams/:
    get:
      tags:
      - HTTP Upstreams
      summary: Return status of all HTTP upstream server groups
      description: Returns status of each HTTP upstream server group and its servers.
      operationId: getHttpUpstreams
      parameters:
      - name: fields
        in: query
        description: Limits which fields of upstream server groups will be output. If the “<literal>fields</literal>” value is empty, only names of upstreams will be output.
        schema:
          type: string
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxHTTPUpstreamMap'
        '404':
          description: Unknown version (*UnknownVersion*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
  /http/upstreams/{httpUpstreamName}/:
    parameters:
    - name: httpUpstreamName
      in: path
      description: The name of an HTTP upstream server group.
      required: true
      schema:
        type: string
    get:
      tags:
      - HTTP Upstreams
      summary: Return status of an HTTP upstream server group
      description: Returns status of a particular HTTP upstream server group and its servers.
      operationId: getHttpUpstreamName
      parameters:
      - name: fields
        in: query
        description: Limits which fields of the upstream server group will be output.
        schema:
          type: string
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxHTTPUpstream'
        '400':
          description: Upstream is static (*UpstreamStatic*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '404':
          description: 'Unknown version (*UnknownVersion*),

            upstream not found (*UpstreamNotFound*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
    delete:
      tags:
      - HTTP Upstreams
      summary: Reset statistics of an HTTP upstream server group
      description: Resets the statistics for each upstream server in an upstream server group and queue statistics.
      operationId: deleteHttpUpstreamStat
      responses:
        '204':
          description: Success
        '400':
          description: Upstream is static (*UpstreamStatic*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '404':
          description: 'Unknown version (*UnknownVersion*),

            upstream not found (*UpstreamNotFound*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '405':
          description: Method disabled (*MethodDisabled*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
  /http/upstreams/{httpUpstreamName}/servers/:
    parameters:
    - name: httpUpstreamName
      in: path
      description: The name of an upstream server group.
      required: true
      schema:
        type: string
    get:
      tags:
      - HTTP Upstreams
      summary: Return configuration of all servers in an HTTP upstream server group
      description: Returns configuration of each server in a particular HTTP upstream server group.
      operationId: getHttpUpstreamServers
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxHTTPUpstreamConfServerMap'
        '400':
          description: Upstream is static (*UpstreamStatic*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '404':
          description: 'Unknown version (*UnknownVersion*),

            upstream not found (*UpstreamNotFound*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
    post:
      tags:
      - HTTP Upstreams
      summary: Add a server to an HTTP upstream server group
      description: Adds a new server to an HTTP upstream server group. Server parameters are specified in the JSON format.
      operationId: postHttpUpstreamServer
      responses:
        '201':
          description: Created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxHTTPUpstreamConfServer'
        '400':
          description: 'Upstream is static (*UpstreamStatic*),

            invalid “**parameter**” value (*UpstreamConfFormatError*),

            missing “*server*” argument (*UpstreamConfFormatError*),

            unknown parameter “**name**” (*UpstreamConfFormatError*),

            nested object or list (*UpstreamConfFormatError*),

            “*error*” while parsing (*UpstreamBadAddress*),

            service upstream “*host*” may not have port (*UpstreamBadAddress*),

            service upstream “*host*” requires domain name (*UpstreamBadAddress*),

            invalid “*weight*” (*UpstreamBadWeight*),

            invalid “*max_conns*” (*UpstreamBadMaxConns*),

            invalid “*max_fails*” (*UpstreamBadMaxFails*),

            invalid “*fail_timeout*” (*UpstreamBadFailTimeout*),

            invalid “*slow_start*” (*UpstreamBadSlowStart*),

            reading request body failed *BodyReadError*),

            route is too long (*UpstreamBadRoute*),

            “*service*” is empty (*UpstreamBadService*),

            no resolver defined to resolve (*UpstreamConfNoResolver*),

            upstream “**name**” has no backup (*UpstreamNoBackup*),

            upstream “**name**” memory exhausted (*UpstreamOutOfMemory*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '404':
          description: 'Unknown version (*UnknownVersion*),

            upstream not found (*UpstreamNotFound*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '405':
          description: Method disabled (*MethodDisabled*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '409':
          description: Entry exists (*EntryExists*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '415':
          description: JSON error (*JsonError*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/NginxHTTPUpstreamConfServer'
        description: Address of a new server and other optional parameters in the JSON format. The “*ID*”, “*backup*”, and “*service*” parameters cannot be changed.
        required: true
  /http/upstreams/{httpUpstreamName}/servers/{httpUpstreamServerId}:
    parameters:
    - name: httpUpstreamName
      in: path
      description: The name of the upstream server group.
      required: true
      schema:
        type: string
    - name: httpUpstreamServerId
      in: path
      description: The ID of the server.
      required: true
      schema:
        type: string
    get:
      tags:
      - HTTP Upstreams
      summary: Return configuration of a server in an HTTP upstream server group
      description: Returns configuration of a particular server in the HTTP upstream server group.
      operationId: getHttpUpstreamPeer
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxHTTPUpstreamConfServer'
        '400':
          description: 'Upstream is static (*UpstreamStatic*),

            invalid server ID (*UpstreamBadServerId*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '404':
          description: 'Server with ID “**id**” does not exist (*UpstreamServerNotFound*),

            unknown version (*UnknownVersion*),

            upstream not found (*UpstreamNotFound*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
    patch:
      tags:
      - HTTP Upstreams
      summary: Modify a server in an HTTP upstream server group
      description: Modifies settings of a particular server in an HTTP upstream server group. Server parameters are specified in the JSON format.
      operationId: patchHttpUpstreamPeer
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxHTTPUpstreamConfServer'
        '400':
          description: 'Upstream is static (*UpstreamStatic*),

            invalid “**parameter**” value (*UpstreamConfFormatError*),

            unknown parameter “**name**” (*UpstreamConfFormatError*),

            nested object or list (*UpstreamConfFormatError*),

            “*error*” while parsing (*UpstreamBadAddress*),

            invalid “*server*” argument (*UpstreamBadAddress*),

            invalid server ID (*UpstreamBadServerId*),

            invalid “*weight*” (*UpstreamBadWeight*),

            invalid “*max_conns*” (*UpstreamBadMaxConns*),

            invalid “*max_fails*” (*UpstreamBadMaxFails*),

            invalid “*fail_timeout*” (*UpstreamBadFailTimeout*),

            invalid “*slow_start*” (*UpstreamBadSlowStart*),

            reading request body failed *BodyReadError*),

            route is too long (*UpstreamBadRoute*),

            “*service*” is empty (*UpstreamBadService*),

            server “**ID**” address is immutable (*UpstreamServerImmutable*),

            server “*ID*” weight is immutable (*UpstreamServerWeightImmutable*),

            upstream “*name*” memory exhausted (*UpstreamOutOfMemory*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '404':
          description: 'Server with ID “**id**” does not exist (*UpstreamServerNotFound*),

            unknown version (*UnknownVersion*),

            upstream not found (*UpstreamNotFound*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '405':
          description: Method disabled (*MethodDisabled*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '415':
          description: JSON error (*JsonError*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/NginxHTTPUpstreamConfServer'
        description: Server parameters, specified in the JSON format. The “*ID*”, “*backup*”, and “*service*” parameters cannot be changed.
        required: true
    delete:
      tags:
      - HTTP Upstreams
      summary: Remove a server from an HTTP upstream server group
      description: Removes a server from an HTTP upstream server group.
      operationId: deleteHttpUpstreamServer
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxHTTPUpstreamConfServerMap'
        '400':
          description: 'Upstream is static (*UpstreamStatic*),

            invalid server ID (*UpstreamBadServerId*),

            server “**id**” not removable (*UpstreamServerImmutable*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '404':
          description: 'Server with ID “**id**” does not exist (*UpstreamServerNotFound*),

            unknown version (*UnknownVersion*),

            upstream not found (*UpstreamNotFound*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
        '405':
          description: Method disabled (*MethodDisabled*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
components:
  schemas:
    NginxHTTPUpstreamConfServer:
      title: HTTP Upstream Server
      description: 'Dynamically configurable parameters of an HTTP upstream

        <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#server">server</a>:

        '
      type: object
      properties:
        id:
          type: integer
          description: The ID of the HTTP upstream server. The ID is assigned automatically and cannot be changed.
          readOnly: true
        server:
          type: string
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#server">address</a> parameter of the HTTP upstream server. When adding a server, it is possible to specify it as a domain name. In this case, changes of the IP addresses that correspond to a domain name will be monitored and automatically applied to the upstream configuration without the need of restarting nginx. This requires the <a href="https://nginx.org/en/docs/http/ngx_http_core_module.html#resolver">resolver</a> directive in the “<code>http</code>” block. See also the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#resolve">resolve</a> parameter of the HTTP upstream server.
        service:
          type: string
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#service">service</a> parameter of the HTTP upstream server. This parameter cannot be changed.
          readOnly: true
        weight:
          type: integer
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#weight">weight</a> parameter of the HTTP upstream server.
        max_conns:
          type: integer
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#max_conns">max_conns</a> parameter of the HTTP upstream server.
        max_fails:
          type: integer
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#max_fails">max_fails</a> parameter of the HTTP upstream server.
        fail_timeout:
          type: string
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#fail_timeout">fail_timeout</a> parameter of the HTTP upstream server.
        slow_start:
          type: string
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#slow_start">slow_start</a> parameter of the HTTP upstream server.
        route:
          type: string
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#route">route</a> parameter of the HTTP upstream server.
        backup:
          type: boolean
          description: When <code>true</code>, adds a <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#backup">backup</a> server. This parameter cannot be changed.
          readOnly: true
        down:
          type: boolean
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#down">down</a> parameter of the HTTP upstream server.
        drain:
          type: boolean
          description: Same as the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#drain">drain</a> parameter of the HTTP upstream server.
        parent:
          type: string
          description: Parent server ID of the resolved server. The ID is assigned automatically and cannot be changed.
          readOnly: true
        host:
          type: string
          description: Hostname of the resolved server. The hostname is assigned automatically and cannot be changed.
          readOnly: true
      example:
        id: 1
        server: 10.0.0.1:8089
        weight: 4
        max_conns: 0
        max_fails: 0
        fail_timeout: 10s
        slow_start: 10s
        route: ''
        backup: true
        down: true
    NginxHTTPUpstreamConfServerMap:
      title: HTTP Upstream Servers
      description: An array of HTTP upstream servers for dynamic configuration.
      type: array
      items:
        $ref: '#/components/schemas/NginxHTTPUpstreamConfServer'
      example:
      - id: 0
        server: 10.0.0.1:8088
        weight: 1
        max_conns: 0
        max_fails: 0
        fail_timeout: 10s
        slow_start: 10s
        route: ''
        backup: false
        down: false
      - id: 1
        server: 10.0.0.1:8089
        weight: 4
        max_conns: 0
        max_fails: 0
        fail_timeout: 10s
        slow_start: 10s
        route: ''
        backup: true
        down: true
    NginxHTTPUpstream:
      title: HTTP Upstream
      type: object
      properties:
        peers:
          $ref: '#/components/schemas/NginxHTTPUpstreamPeerMap'
        keepalive:
          type: integer
          description: The current number of idle <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive">keepalive</a> connections.
        zombies:
          type: integer
          description: The current number of servers removed from the group but still processing active client requests.
        zone:
          type: string
          description: The name of the shared memory <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#zone">zone</a> that keeps the group’s configuration and run-time state.
        queue:
          type: object
          description: 'For the requests <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#queue">queue</a>, the following data are provided:

            '
          properties:
            size:
              type: integer
              description: The current number of requests in the queue.
            max_size:
              type: integer
              description: The maximum number of requests that can be in the queue at the same time.
            overflows:
              type: integer
              description: The total number of requests rejected due to the queue overflow.
      example:
        upstream_backend:
          peers:
          - id: 0
            server: 10.0.0.1:8088
            name: 10.0.0.1:8088
            backup: false
            weight: 5
            state: up
            active: 0
            ssl:
              handshakes: 620311
              handshakes_failed: 3432
              session_reuses: 36442
              no_common_protocol: 4
              handshake_timeout: 0
              peer_rejected_cert: 0
              verify_failures:
                expired_cert: 2
                revoked_cert: 1
                hostname_mismatch: 2
                other: 1
            max_conns: 20
            requests: 667231
            header_time: 20
            response_time: 36
            response_time_hist:
              count: 9817
              sum: 57625
              buckets:
                5: 4428
                10: 4755
                25: 350
                50: 235
                75: 54
                100: 47
                250: 1
                500: 0
                750: 0
                1000: 0
                2500: 0
                5000: 0
                7500: 0
                10000: 0
                inf: 0
            responses:
              1xx: 0
              2xx: 666310
              3xx: 0
              4xx: 915
              5xx: 6
              codes:
                200: 666310
                404: 915
                503: 6
              total: 667231
            sent: 251946292
            received: 19222475454
            fails: 0
            unavail: 0
            health_checks:
              checks: 26214
              fails: 0
              unhealthy: 0
              last_passed: true
            downtime: 0
            downstart: 2022-06-28 11:09:21.602000+00:00
            selected: 2022-06-28 15:01:25+00:00
          - id: 1
            server: 10.0.0.1:8089
            name: 10.0.0.1:8089
            backup: true
            weight: 1
            state: unhealthy
            active: 0
            max_conns: 20
            requests: 0
            responses:
              1xx: 0
              2xx: 0
              3xx: 0
              4xx: 0
              5xx: 0
              codes: {}
              total: 0
            sent: 0
            received: 0
            fails: 0
            unavail: 0
            health_checks:
              checks: 26284
              fails: 26284
              unhealthy: 1
              last_passed: false
            downtime: 262925617
            downstart: 2022-06-28 11:09:21.602000+00:00
            selected: 2022-06-28 15:01:25+00:00
          keepalive: 0
          zombies: 0
          zone: upstream_backend
    NginxError:
      title: Error
      description: 'nginx error object.

        '
      type: object
      properties:
        error:
          type: object
          properties:
            status:
              type: integer
              description: HTTP error code.
            text:
              type: string
              description: Error description.
            code:
              type: string
              description: Internal nginx error code.
        request_id:
          type: string
          description: The ID of the request, equals the value of the <a href="https://nginx.org/en/docs/http/ngx_http_core_module.html#var_request_id">$request_id</a> variable.
        href:
          type: string
          description: Link to reference documentation.
    NginxHTTPUpstreamMap:
      title: HTTP Upstreams
      description: 'Status information of all HTTP

        <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#zone">dynamically configurable</a>

        <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#upstream">groups</a>.

        '
      type: object
      additionalProperties:
        $ref: '#/components/schemas/NginxHTTPUpstream'
      example:
        trac-backend:
          peers:
          - id: 0
            server: 10.0.0.1:8088
            name: 10.0.0.1:8088
            backup: false
            weight: 5
            state: up
            active: 0
            ssl:
              handshakes: 620311
              handshakes_failed: 3432
              session_reuses: 36442
              no_common_protocol: 4
              handshake_timeout: 0
              peer_rejected_cert: 0
              verify_failures:
                expired_cert: 2
                revoked_cert: 1
                hostname_mismatch: 2
                other: 1
            requests: 667231
            header_time: 20
            response_time: 36
            response_time_hist:
              count: 9817
              sum: 57625
              buckets:
                5: 4428
                10: 4755
                25: 350
                50: 235
                75: 54
                100: 47
                250: 1
                500: 0
                750: 0
                1000: 0
                2500: 0
                5000: 0
                7500: 0
                10000: 0
                inf: 0
            responses:
              1xx: 0
              2xx: 666310
              3xx: 0
              4xx: 915
              5xx: 6
              codes:
                200: 666310
                404: 915
                503: 6
              total: 667231
            sent: 251946292
            received: 19222475454
            fails: 0
            unavail: 0
            health_checks:
              checks: 26214
              fails: 0
              unhealthy: 0
              last_passed: true
            downtime: 0
            downstart: 2022-06-28 11:09:21.602000+00:00
            selected: 2022-06-28 15:01:25+00:00
          - id: 1
            server: 10.0.0.1:8089
            name: 10.0.0.1:8089
            backup: true
            weight: 1
            state: unhealthy
            active: 0
            requests: 0
            responses:
              1xx: 0
              2xx: 0
              3xx: 0
              4xx: 0
              5xx: 0
              codes: {}
              total: 0
            sent: 0
            received: 0
            fails: 0
            unavail: 0
            health_checks:
              checks: 26284
              fails: 26284
              unhealthy: 1
              last_passed: false
            downtime: 262925617
            downstart: 2022-06-28 11:09:21.602000+00:00
            selected: 2022-06-28 15:01:25+00:00
          keepalive: 0
          zombies: 0
          zone: trac-backend
        hg-backend:
          peers:
          - id: 0
            server: 10.0.0.1:8088
            name: 10.0.0.1:8088
            backup: false
            weight: 5
            state: up
            active: 0
            ssl:
              handshakes: 620311
              handshakes_failed: 3432
              session_reuses: 36442
              no_common_protocol: 4
              handshake_timeout: 0
              peer_rejected_cert: 0
              verify_failures:
                expired_cert: 2
                revoked_cert: 1
                hostname_mismatch: 2
                other: 1
            requests: 667231
            header_time: 20
            response_time: 36
            response_time_hist:
              count: 9817
              sum: 57625
              buckets:
                5: 4428
                10: 4755
                25: 350
                50: 235
                75: 54
                100: 47
                250: 1
                500: 0
                750: 0
                1000: 0
                2500: 0
                5000: 0
                7500: 0
                10000: 0
                inf: 0
            responses:
              1xx: 0
              2xx: 666310
              3xx: 0
              4xx: 915
              5xx: 6
              codes:
                200: 666310
                404: 915
                503: 6
              total: 667231
            sent: 251946292
            received: 19222475454
            fails: 0
            unavail: 0
            health_checks:
              checks: 26214
              fails: 0
              unhealthy: 0
              last_passed: true
            downtime: 0
            downstart: 2022-06-28 11:09:21.602000+00:00
            selected: 2022-06-28 15:01:25+00:00
          - id: 1
            server: 10.0.0.1:8089
            name: 10.0.0.1:8089
            backup: true
            weight: 1
            state: unhealthy
            active: 0
            requests: 0
            responses:
              1xx: 0
              2xx: 0
              3xx: 0
              4xx: 0
              5xx: 0
              codes: {}
              total: 0
            sent: 0
            received: 0
            fails: 0
            unavail: 0
            health_checks:
              checks: 26284
              fails: 26284
              unhealthy: 1
              last_passed: false
            downtime: 262925617
            downstart: 2022-06-28 11:09:21.602000+00:00
            selected: 2022-06-28 15:01:25+00:00
          keepalive: 0
          zombies: 0
          zone: hg-backend
    NginxHTTPUpstreamPeerMap:
      title: HTTP Upstream Servers
      description: 'An array of HTTP

        <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#upstream">upstream servers</a>.

        '
      type: array
      items:
        $ref: '#/components/schemas/NginxHTTPUpstreamPeer'
    NginxHTTPUpstreamPeer:
      title: HTTP Upstream Server
      type: object
      properties:
        id:
          type: integer
          description: The ID of the server.
          readOnly: true
        server:
          type: string
          description: An  <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#server">address</a> of the server.
        service:
          type: string
          description: The <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#service">service</a> parameter value of the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#server">server</a> directive.
        name:
          type: string
          description: The name of the server specified in the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#server">server</a> directive.
          readOnly: true
        backup:
          type: boolean
          description: A boolean value indicating whether the server is a <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#backup">backup</a> server.
        weight:
          type: integer
          description: <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#weight">Weight</a> of the server.
        state:
          type: string
          enum:
          - up
          - draining
          - down
          - unavail
          - checking
          - unhealthy
          description: Current state, which may be one of “<code>up</code>”, “<code>draining</code>”, “<code>down</code>”, “<code>unavail</code>”, “<code>checking</code>”, and “<code>unhealthy</code>”.
        active:
          type: integer
          description: The current number of active connections.
          readOnly: true
        ssl:
          type: object
          readOnly: true
          properties:
            handshakes:
              type: integer
              description: The total number of successful SSL handshakes.
              readOnly: true
            handshakes_failed:
              type: integer
              description: The total number of failed SSL handshakes.
              readOnly: true
            session_reuses:
              type: integer
              description: The total number of session reuses during SSL handshake.
              readOnly: true
            no_common_protocol:
              type: integer
              description: The number of SSL handshakes failed because of no common protocol.
            handshake_timeout:
              type: integer
              description: The number of SSL handshakes failed because of a timeout.
            peer_rejected_cert:
              type: integer
              description: The number of failed SSL handshakes when nginx presented the certificate to the upstream server but it was rejected with a corresponding alert message.
            verify_failures:
              type: object
              description: SSL certificate verification errors
              properties:
                expired_cert:
                  type: integer
                  description: An expired or not yet valid certificate was presented by an upstream server.
                revoked_cert:
                  type: integer
                  description: A revoked certificate was presented by an upstream server.
                hostname_mismatch:
                  type: integer
                  description: Server's certificate doesn't match the hostname.
                other:
                  type: integer
                  description: Other SSL certificate verification errors.
        max_conns:
          type: integer
          description: The <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#max_conns">max_conns</a> limit for the server.
        requests:
          type: integer
          description: The total number of client requests forwarded to this server.
          readOnly: true
        responses:
          type: object
          readOnly: true
          properties:
            1xx:
              type: integer
              description: The number of responses with “<code>1xx</code>” status codes.
              readOnly: true
            2xx:
              type: integer
              description: The number of responses with “<code>2xx</code>” status codes.
              readOnly: true
            3xx:
              type: integer
              description: The number of responses with “<code>3xx</code>” status codes.
              readOnly: true
            4xx:
              type: integer
              description: The number of responses with “<code>4xx</code>” status codes.
              readOnly: true
            5xx:
              type: integer
              description: The number of responses with “<code>5xx</code>” status codes.
              readOnly: true
            codes:
              type: object
              description: The number of responses per each status code.
              readOnly: true
              properties:
                codeNumber:
                  type: integer
                  description: The number of responses with this particular status code.
                  readOnly: true
            total:
              type: integer
              description: The total number of responses obtained from this server.
              readOnly: true
        sent:
          type: integer
          description: The total number of bytes sent to this server.
          readOnly: true
        received:
          type: integer
          description: The total number of bytes received from this server.
          readOnly: true
        fails:
          type: integer
          description: The total number of unsuccessful attempts to communicate with the server.
          readOnly: true
        unavail:
          type: integer
          description: How many times the server became unavailable for client requests (state “<code>unavail</code>”) due to the number of unsuccessful attempts reaching the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#max_fails">max_fails</a> threshold.
          readOnly: true
        health_checks:
          type: object
          readOnly: true
          properties:
            checks:
              type: integer
              description: The total number of <a href="https://nginx.org/en/docs/http/ngx_http_upstream_hc_module.html#health_check">health check</a> requests made.
            fails:
              type: integer
              description: The number of failed health checks.
            unhealthy:
              type: integer
              description: How many times the server became unhealthy (state “<code>unhealthy</code>”).
            last_passed:
              type: boolean
              description: Boolean indicating if the last health check request was successful and passed <a href="https://nginx.org/en/docs/http/ngx_http_upstream_hc_module.html#match">tests</a>.
        downtime:
          type: integer
          readOnly: true
          description: Total time the server was in the “<code>unavail</code>”, “<code>checking</code>”, and “<code>unhealthy</code>” states.
        downstart:
          type: string
          format: date-time
          readOnly: true
          description: The time when the server became “<code>unavail</code>”, “<code>checking</code>”, or “<code>unhealthy</code>”, in the ISO 8601 format with millisecond resolution.
        selected:
          type: string
          format: date-time
          readOnly: true
          description: The time when the server was last selected to process a request, in the ISO 8601 format with millisecond resolution.
        header_time:
          type: integer
          readOnly: true
          description: The average time to get the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#var_upstream_header_time">response header</a> from the server.
        response_time:
          type: integer
          readOnly: true
          description: The average time to get the <a href="https://nginx.org/en/docs/http/ngx_http_upstream_module.html#var_upstream_response_time">full response</a> from the server.
        response_time_hist:
          type: object
          description: Histogram of upstream response times collected per upstream server.
          readOnly: true
          properties:
            count:
              type: integer
              description: Total number of recorded responses.
              readOnly: true
            sum:
              type: integer
              description: Sum of all recorded upstream response times, in milliseconds.
              readOnly: true
            buckets:
              title: Histogram bucket counters
              description: 'Histogram bucket counters for upstream response times, in milliseconds.

                Each bucket name ("5","10","25","50", etc.) is a time limit in milliseconds.

                Each bucket value is the number of responses within that time bucket.

                The "inf" bucket counts responses greater than 10000 ms.

                '
              type: object
              readOnly: true
              properties:
                '5':
                  type: integer
                  description: The total number of responses with response time less than or equal to 5 ms.
                '10':
                  type: integer
                  description: The total number of responses with response time greater than 5 ms and less than or equal to 10 ms.
                '25':
                  type: integer
                  description: The total number of responses with response time greater than 10 ms and less than or equal to 25 ms.
                '50':
                  type: integer
                  description: The total number of responses with response time greater than 25 ms and less than or equal to 50 ms.
                '75':
                  type: integer
                  description: The total number of responses with response time greater than 50 ms and less than or equal to 75 ms.
                '100':
                  type: integer
                  description: The total number of responses with response time greater than 75 ms and less than or equal to 100 ms.
                '250':
                  type: integer
                  description: The total number of responses with response time greater than 100 ms and less than or equal to 250 ms.
                '500':
                  type: integer
                  description: The total number of responses with response time greater than 250 ms and less than or equal to 500 ms.
                '750':
                  type: integer
                  description: The total number of responses with response time greater than 500 ms and less than or equal to 750 ms.
                '1000':
                  type: integer
                  description: The total number of responses with response time greater than 750 ms and less than or equal to 1000 ms.
                '2500':
                  type: integer
                  description: The total number of responses with response time greater than 1000 ms and less than or equal to 2500 ms.
                '5000':
                  type: integer
                  description: The total number of responses with response time greater than 2500 ms and less than or equal to 5000 ms.
                '7500':
                  type: integer
                  description: The total number of responses with response time greater than 5000 ms and less than or equal to 7500 ms.
                '10000':
                  type: integer
                  description: The total number of responses with response time greater than 7500 ms and less than or equal to 10000 ms.
                inf:
                  type: integer
                  description: The total number of observations with response time greater than 10000 ms.