# # Backend

## Properties

Name | Type | Description | Notes
------------ | ------------- | ------------- | -------------
**address** | **string** | A hostname, IPv4, or IPv6 address for the backend. This is the preferred way to specify the location of your backend. | [optional] 
**auto_loadbalance** | **bool** | Whether or not this backend should be automatically load balanced. If true, all backends with this setting that don&#39;t have a `request_condition` will be selected based on their `weight`. | [optional] 
**between_bytes_timeout** | **int** | Maximum duration in milliseconds that Fastly will wait while receiving no data on a download from a backend. If exceeded, for Delivery services, the response received so far will be considered complete and the fetch will end. For Compute services, timeout expiration is treated as a failure of the backend connection, and an error is generated. May be set at runtime using `bereq.between_bytes_timeout`. | [optional] 
**client_cert** | **string** | Unused. | [optional] 
**comment** | **string** | A freeform descriptive note. | [optional] 
**connect_timeout** | **int** | Maximum duration in milliseconds to wait for a connection to this backend to be established. If exceeded, the connection is aborted and a synthetic `503` response will be presented instead. May be set at runtime using `bereq.connect_timeout`. | [optional] 
**first_byte_timeout** | **int** | Maximum duration in milliseconds to wait for the server response to begin after a TCP connection is established and the request has been sent. If exceeded, the connection is aborted and a synthetic `503` response will be presented instead. May be set at runtime using `bereq.first_byte_timeout`. | [optional] 
**fetch_timeout** | **int** | Maximum duration in milliseconds to wait for the entire response to be received after a TCP connection is established and the request has been sent. If exceeded, the connection is aborted and a synthetic `503` response will be presented instead. May be set at runtime using `bereq.fetch_timeout`. | [optional] 
**healthcheck** | **string** | The name of the healthcheck to use with this backend. | [optional] 
**hostname** | **string** | The hostname of the backend. May be used as an alternative to `address` to set the backend location. | [optional] 
**ipv4** | **string** | IPv4 address of the backend. May be used as an alternative to `address` to set the backend location. | [optional] 
**ipv6** | **string** | IPv6 address of the backend. May be used as an alternative to `address` to set the backend location. | [optional] 
**keepalive_time** | **int** | How long in seconds to keep a persistent connection to the backend between requests. By default, Varnish keeps connections open as long as it can. | [optional] 
**max_conn** | **int** | Maximum number of concurrent connections this backend will accept. | [optional] 
**max_tls_version** | **string** | Maximum allowed TLS version on SSL connections to this backend. If your backend server is not able to negotiate a connection meeting this constraint, a synthetic `503` error response will be generated. | [optional] 
**min_tls_version** | **string** | Minimum allowed TLS version on SSL connections to this backend. If your backend server is not able to negotiate a connection meeting this constraint, a synthetic `503` error response will be generated. | [optional] 
**name** | **string** | The name of the backend. | [optional] 
**override_host** | **string** | If set, will replace the client-supplied HTTP `Host` header on connections to this backend. Applied after VCL has been processed, so this setting will take precedence over changing `bereq.http.Host` in VCL. | [optional] 
**port** | **int** | Port on which the backend server is listening for connections from Fastly. Setting `port` to 80 or 443 will also set `use_ssl` automatically (to false and true respectively), unless explicitly overridden by setting `use_ssl` in the same request. | [optional] 
**prefer_ipv6** | **bool** | Prefer IPv6 connections to origins for hostname backends. Default is &#39;false&#39; for Delivery services and &#39;true&#39; for Compute services. | [optional] 
**request_condition** | **string** | Name of a Condition, which if satisfied, will select this backend during a request. If set, will override any `auto_loadbalance` setting. By default, the first backend added to a service is selected for all requests. | [optional] 
**share_key** | **string** | Value that when shared across backends will enable those backends to share the same health check. | [optional] 
**shield** | **string** | Identifier of the POP to use as a [shield](https://www.fastly.com/documentation/guides/getting-started/hosts/shielding/). | [optional] 
**ssl_ca_cert** | **string** | CA certificate attached to origin. | [optional] 
**ssl_cert_hostname** | **string** | Overrides `ssl_hostname`, but only for cert verification. Does not affect SNI at all. | [optional] 
**ssl_check_cert** | **bool** | Be strict on checking SSL certs. | [optional]  [defaults to true]
**ssl_ciphers** | **string** | List of [OpenSSL ciphers](https://www.openssl.org/docs/man1.1.1/man1/ciphers.html) to support for connections to this origin. If your backend server is not able to negotiate a connection meeting this constraint, a synthetic `503` error response will be generated. | [optional] 
**ssl_client_cert** | **string** | Client certificate attached to origin. | [optional] 
**ssl_client_key** | **string** | Client key attached to origin. | [optional] 
**ssl_hostname** | **string** | Use `ssl_cert_hostname` and `ssl_sni_hostname` to configure certificate validation. | [optional] 
**ssl_sni_hostname** | **string** | Overrides `ssl_hostname`, but only for SNI in the handshake. Does not affect cert validation at all. | [optional] 
**tcp_keepalive_enable** | **bool** | Whether to enable TCP keepalives for backend connections. Varnish defaults to using keepalives if this is unspecified. | [optional] 
**tcp_keepalive_interval** | **int** | Interval in seconds between subsequent keepalive probes. | [optional]  [defaults to 10]
**tcp_keepalive_probes** | **int** | Number of unacknowledged probes to send before considering the connection dead. | [optional]  [defaults to 3]
**tcp_keepalive_time** | **int** | Interval in seconds between the last data packet sent and the first keepalive probe. | [optional]  [defaults to 300]
**use_ssl** | **bool** | Whether or not to require TLS for connections to this backend. | [optional] 
**weight** | **int** | Weight used to load balance this backend against others. May be any positive integer. If `auto_loadbalance` is true, the chance of this backend being selected is equal to its own weight over the sum of all weights for backends that have `auto_loadbalance` set to true. | [optional] 


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