openapi: 3.2.0
info:
  version: '9.0'
  title: NGINX Plus REST Stream 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: Stream Upstreams
paths:
  /stream/upstreams/:
    get:
      tags:
      - Stream Upstreams
      summary: Return status of all stream upstream server groups
      description: Returns status of each stream upstream server group and its servers.
      operationId: getStreamUpstreams
      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/NginxStreamUpstreamMap'
        '404':
          description: Unknown version (*UnknownVersion*)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
  /stream/upstreams/{streamUpstreamName}/:
    parameters:
    - name: streamUpstreamName
      in: path
      description: The name of a stream upstream server group.
      required: true
      schema:
        type: string
    get:
      tags:
      - Stream Upstreams
      summary: Return status of a stream upstream server group
      description: Returns status of a particular stream upstream server group and its servers.
      operationId: getStreamUpstream
      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/NginxStreamUpstream'
        '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:
      - Stream Upstreams
      summary: Reset statistics of a stream upstream server group
      description: Resets the statistics for each upstream server in an upstream server group.
      operationId: deleteStreamUpstreamStat
      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'
  /stream/upstreams/{streamUpstreamName}/servers/:
    parameters:
    - name: streamUpstreamName
      in: path
      description: The name of an upstream server group.
      required: true
      schema:
        type: string
    get:
      tags:
      - Stream Upstreams
      summary: Return configuration of all servers in a stream upstream server group
      description: Returns configuration of each server in a particular stream upstream server group.
      operationId: getStreamUpstreamServers
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxStreamUpstreamConfServerMap'
        '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:
      - Stream Upstreams
      summary: Add a server to a stream upstream server group
      description: Adds a new server to a stream upstream server group. Server parameters are specified in the JSON format.
      operationId: postStreamUpstreamServer
      responses:
        '201':
          description: Created
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxStreamUpstreamConfServer'
        '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*),

            no port in server “*host*” (*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*),

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

            no resolver defined to resolve (*UpstreamConfNoResolver*),

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

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

            reading request body failed *BodyReadError*)

            '
          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/NginxStreamUpstreamConfServer'
        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
  /stream/upstreams/{streamUpstreamName}/servers/{streamUpstreamServerId}:
    parameters:
    - name: streamUpstreamName
      in: path
      description: The name of the upstream server group.
      required: true
      schema:
        type: string
    - name: streamUpstreamServerId
      in: path
      description: The ID of the server.
      required: true
      schema:
        type: string
    get:
      tags:
      - Stream Upstreams
      summary: Return configuration of a server in a stream upstream server group
      description: Returns configuration of a particular server in the stream upstream server group.
      operationId: getStreamUpstreamServer
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxStreamUpstreamConfServer'
        '400':
          description: 'Upstream is static (*UpstreamStatic*),

            invalid server ID (*UpstreamBadServerId*)

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

            upstream not found (*UpstreamNotFound*),

            server with ID “**id**” does not exist (*UpstreamServerNotFound*)

            '
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxError'
    patch:
      tags:
      - Stream Upstreams
      summary: Modify a server in a stream upstream server group
      description: Modifies settings of a particular server in a stream upstream server group. Server parameters are specified in the JSON format.
      operationId: patchStreamUpstreamServer
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxStreamUpstreamConfServer'
        '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*),

            no port in server “*host*” (*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*),

            “*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/NginxStreamUpstreamConfServer'
        description: Server parameters, specified in the JSON format. The “*ID*”, “*backup*”, and “*service*” parameters cannot be changed.
        required: true
    delete:
      tags:
      - Stream Upstreams
      summary: Remove a server from a stream upstream server group
      description: Removes a server from a stream server group.
      operationId: deleteStreamUpstreamServer
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/NginxStreamUpstreamConfServerMap'
        '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:
    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.
    NginxStreamUpstreamConfServer:
      title: Stream Upstream Server
      description: 'Dynamically configurable parameters of a stream upstream

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

        '
      type: object
      properties:
        id:
          type: integer
          description: The ID of the stream 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/stream/ngx_stream_upstream_module.html#server">address</a> parameter of the stream 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/stream/ngx_stream_core_module.html#resolver">resolver</a> directive in the “<code>stream</code>” block. See also the <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#resolve">resolve</a> parameter of the stream upstream server.
        service:
          type: string
          description: Same as the <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#service">service</a> parameter of the stream upstream server. This parameter cannot be changed.
          readOnly: true
        weight:
          type: integer
          description: Same as the <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#weight">weight</a> parameter of the stream upstream server.
        max_conns:
          type: integer
          description: Same as the <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#max_conns">max_conns</a> parameter of the stream upstream server.
        max_fails:
          type: integer
          description: Same as the <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#max_fails">max_fails</a> parameter of the stream upstream server.
        fail_timeout:
          type: string
          description: Same as the <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#fail_timeout">fail_timeout</a> parameter of the stream upstream server.
        slow_start:
          type: string
          description: Same as the <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#slow_start">slow_start</a> parameter of the stream upstream server.
        backup:
          type: boolean
          description: When <code>true</code>, adds a <a href="https://nginx.org/en/docs/stream/ngx_stream_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/stream/ngx_stream_upstream_module.html#down">down</a> parameter of the stream 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: 0
        server: 10.0.0.1:12348
        weight: 1
        max_conns: 0
        max_fails: 1
        fail_timeout: 10s
        slow_start: 0
        backup: false
        down: false
    NginxStreamUpstream:
      title: Stream Upstream
      type: object
      properties:
        peers:
          $ref: '#/components/schemas/NginxStreamUpstreamPeerMap'
        zombies:
          type: integer
          description: The current number of servers removed from the group but still processing active client connections.
        zone:
          type: string
          description: The name of the shared memory <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#zone">zone</a> that keeps the group’s configuration and run-time state.
      example:
        dns:
          peers:
          - id: 0
            server: 10.0.0.1:12347
            name: 10.0.0.1:12347
            backup: false
            weight: 5
            state: up
            active: 0
            ssl:
              handshakes: 200
              handshakes_failed: 4
              session_reuses: 189
              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: 50
            connections: 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: 10.0.0.1:12348
            name: 10.0.0.1:12348
            backup: true
            weight: 1
            state: unhealthy
            active: 0
            max_conns: 50
            connections: 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
          zombies: 0
          zone: dns
    NginxStreamUpstreamPeerMap:
      title: Stream Upstream Servers
      description: Array of stream upstream servers.
      type: array
      items:
        $ref: '#/components/schemas/NginxStreamUpstreamPeer'
    NginxStreamUpstreamMap:
      title: Stream Upstreams
      description: Status information of stream upstream server groups.
      type: object
      additionalProperties:
        $ref: '#/components/schemas/NginxStreamUpstream'
      example:
        mysql_backends:
          peers:
          - id: 0
            server: 10.0.0.1:12345
            name: 10.0.0.1:12345
            backup: false
            weight: 5
            state: up
            active: 0
            ssl:
              handshakes: 1045
              handshakes_failed: 89
              session_reuses: 321
              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: 30
            connecions: 1231
            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: 10.0.0.1:12346
            name: 10.0.0.1:12346
            backup: true
            weight: 1
            state: unhealthy
            active: 0
            max_conns: 30
            connections: 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
          zombies: 0
          zone: mysql_backends
        dns:
          peers:
          - id: 0
            server: 10.0.0.1:12347
            name: 10.0.0.1:12347
            backup: false
            weight: 5
            state: up
            active: 0
            ssl:
              handshakes: 5268
              handshakes_failed: 121
              session_reuses: 854
              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: 30
            connections: 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: 10.0.0.1:12348
            name: 10.0.0.1:12348
            backup: true
            weight: 1
            state: unhealthy
            active: 0
            connections: 0
            max_conns: 30
            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
          zombies: 0
          zone: dns
    NginxStreamUpstreamConfServerMap:
      title: Stream Upstream Servers
      description: 'An array of stream upstream servers for dynamic configuration.

        '
      type: array
      items:
        $ref: '#/components/schemas/NginxStreamUpstreamConfServer'
      example:
      - id: 0
        server: 10.0.0.1:12348
        weight: 1
        max_conns: 0
        max_fails: 1
        fail_timeout: 10s
        slow_start: 0
        backup: false
        down: false
      - id: 1
        server: 10.0.0.1:12349
        weight: 1
        max_conns: 0
        max_fails: 1
        fail_timeout: 10s
        slow_start: 0
        backup: false
        down: false
    NginxStreamUpstreamPeer:
      title: Stream 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/stream/ngx_stream_upstream_module.html#server">address</a> of the server.
        service:
          type: string
          description: The <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#service">service</a> parameter value of the <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#server">server</a> directive.
        name:
          type: string
          format: hostname
          description: The name of the server specified in the <a href="https://nginx.org/en/docs/stream/ngx_stream_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/stream/ngx_stream_upstream_module.html#backup">backup</a> server.
        weight:
          type: integer
          description: <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_module.html#weight">Weight</a> of the server.
        state:
          type: string
          readOnly: true
          enum:
          - up
          - down
          - unavail
          - checking
          - unhealthy
          description: Current state, which may be one of “<code>up</code>”, “<code>down</code>”, “<code>unavail</code>”, “<code>checking</code>”, or “<code>unhealthy</code>”.
        active:
          type: integer
          description: The current number of 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/stream/ngx_stream_upstream_module.html#max_conns">max_conns</a> limit for the server.
        connections:
          type: integer
          description: The total number of client connections forwarded to this server.
          readOnly: true
        connect_time:
          type: integer
          description: The average time to connect to the upstream server.
          readOnly: true
        first_byte_time:
          type: integer
          description: The average time to receive the first byte of data.
          readOnly: true
        response_time:
          type: integer
          description: The average time to receive the last byte of data.
          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 connections (state “<code>unavail</code>”) due to the number of unsuccessful attempts reaching the <a href="https://nginx.org/en/docs/stream/ngx_stream_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/stream/ngx_stream_upstream_hc_module.html#health_check">health check</a> requests made.
              readOnly: true
            fails:
              type: integer
              description: The number of failed health checks.
              readOnly: true
            unhealthy:
              type: integer
              description: How many times the server became unhealthy (state “<code>unhealthy</code>”).
              readOnly: true
            last_passed:
              type: boolean
              description: Boolean indicating whether the last health check request was successful and passed <a href="https://nginx.org/en/docs/stream/ngx_stream_upstream_hc_module.html#match">tests</a>.
              readOnly: true
        downtime:
          type: integer
          description: Total time the server was in the “<code>unavail</code>”, “<code>checking</code>”, and “<code>unhealthy</code>” states.
          readOnly: true
        downstart:
          type: string
          format: date-time
          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.
          readOnly: true
        selected:
          type: string
          format: date-time
          description: The time when the server was last selected to process a connection, in the ISO 8601 format with millisecond resolution.
          readOnly: true