--- title: HealthcheckBuilder summary: A builder structure for generating healthchecks for a dynamic backend url: https://www.fastly.com/documentation/reference/compute/sdks/rust/fastly/experimental/dynamic_backend_healthchecks/struct.HealthcheckBuilder/ --- **Kind:** Struct **Module:** [dynamic_backend_healthchecks](https://www.fastly.com/documentation/reference/compute/sdks/rust/fastly/experimental/dynamic_backend_healthchecks/) **Package:** fastly 0.13.1 **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#21 ```rust pub struct HealthcheckBuilder { /* private fields */ } ``` A builder structure for generating healthchecks for a dynamic backend This structure can be constructed using either [`Backend::healthcheck_builder()`](https://www.fastly.com/documentation/reference/compute/sdks/rust/fastly/backend/struct.Backend/#method-healthcheck_builder) or its own [`new()`](https://www.fastly.com/documentation/reference/compute/sdks/rust/fastly/experimental/dynamic_backend_healthchecks/struct.HealthcheckBuilder/#method-new) method, and will generate a new healthcheck for use by the `DynamicBackendBuilder` after consuming the `BackendBuilder` with `finish()`. ## Methods ### expected_status **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#205 ```rust fn expected_status(self, value: u16) -> Self ``` Sets the HTTP status code that signifies a healthy state. Defaults to 200. **Parameters** - `self`: `Self` - `value`: `u16` **Returns** `Self` ### get_expected_status **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#148 ```rust fn get_expected_status(&self) -> u16 ``` Returns the expected_status from the HealthcheckBuilder **Parameters** - `self`: `&Self` **Returns** `u16` ### get_host **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#133 ```rust fn get_host(&self) -> &str ``` Returns the host from the HealthcheckBuilder **Parameters** - `self`: `&Self` **Returns** `&str` ### get_initial **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#163 ```rust fn get_initial(&self) -> u32 ``` Returns the initial from the HealthcheckBuilder **Parameters** - `self`: `&Self` **Returns** `u32` ### get_interval_ms **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#168 ```rust fn get_interval_ms(&self) -> Duration ``` Returns the interval_ms from the HealthcheckBuilder **Parameters** - `self`: `&Self` **Returns** `Duration` ### get_method **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#138 ```rust fn get_method(&self) -> &str ``` Returns the method from the HealthcheckBuilder **Parameters** - `self`: `&Self` **Returns** `&str` ### get_path **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#143 ```rust fn get_path(&self) -> &PathAndQuery ``` Returns the path from the HealthcheckBuilder **Parameters** - `self`: `&Self` **Returns** `&PathAndQuery` ### get_threshold **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#158 ```rust fn get_threshold(&self) -> u32 ``` Returns the threshold from the HealthcheckBuilder **Parameters** - `self`: `&Self` **Returns** `u32` ### get_timeout_ms **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#173 ```rust fn get_timeout_ms(&self) -> Duration ``` Returns the timeout_ms from the HealthcheckBuilder **Parameters** - `self`: `&Self` **Returns** `Duration` ### get_window **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#153 ```rust fn get_window(&self) -> u32 ``` Returns the window from the HealthcheckBuilder **Parameters** - `self`: `&Self` **Returns** `u32` ### host **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#180 ```rust fn host(self, name: impl ToString) -> Self ``` Set the Host header to set when making the request (e.g. example.com). A common mistake is setting the wrong host header, which causes the health check to fail. **Parameters** - `self`: `Self` - `name`: `impl ToString` **Returns** `Self` ### initial **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#232 ```rust fn initial(self, value: u32) -> Self ``` Set the number of successes to assume are successful when beginning a health check. Must not be greater than the current window. Defaults to 4. **Parameters** - `self`: `Self` - `value`: `u32` **Returns** `Self` ### interval_ms **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#242 ```rust fn interval_ms(self, value: Duration) -> Self ``` Set the interval in milliseconds where a health check should be performed. Times must be 1 second to 1 hour inclusive. Must be less than the current timeout_ms. Defaults to 15000ms. **Parameters** - `self`: `Self` - `value`: `Duration` **Returns** `Self` ### method **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#188 ```rust fn method(self, value: impl ToString) -> Self ``` Set an HTTP verb (i.e., HEAD, GET, or POST) to use when performing the health check. Defaults to "GET". **Parameters** - `self`: `Self` - `value`: `impl ToString` **Returns** `Self` ### new **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#50 ```rust fn new(host: impl ToString) -> Self ``` Create a new health check builder for a dynamic backend. The argument is a string describing the backend host on which to check health checks on. This can be of the form: * `""` * `""` * `":"` * `":"` The builder will start with default values for all other possible fields for the health check, which can be overridden using the other methods provided. Use `BackendBuilder::healthcheck` to add the health check to a specific Dynamic Backend and call `BackendBuilder::finish()` to complete the construction of the dynamic backend. Values for health checks have strict limits to prevent ill-use. If you create a health check with a value that breaks these limits, `finish()` will error with a `BackendCreationError:InvalidHealthcheckValues` **Parameters** - `host`: `impl ToString` **Returns** `Self` ### path **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#197 ```rust fn path(self, value: impl ToString) -> Self ``` Set a path to visit on your origins when performing the check. Use a unique path. For example, use /website-healthcheck.txt, not / or /healthcheck. Defaults to "/". **Parameters** - `self`: `Self` - `value`: `impl ToString` **Returns** `Self` ### threshold **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#223 ```rust fn threshold(self, value: u32) -> Self ``` Set the number of health checks that must be successful within the window to be considered healthy. Must not be greater than the current window. Defaults to 3. **Parameters** - `self`: `Self` - `value`: `u32` **Returns** `Self` ### timeout_ms **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#252 ```rust fn timeout_ms(self, value: Duration) -> Self ``` Set the time in milliseconds in which to perform the health check. Note that querying the health check renews the timer. Must not be less than the current interval_ms. Defaults to 5000ms. **Parameters** - `self`: `Self` - `value`: `Duration` **Returns** `Self` ### validate **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#66 ```rust fn validate(&self) -> Result<(), BackendCreationError> ``` Validate that the current health check has acceptable values **Parameters** - `self`: `&Self` **Returns** `Result<(), BackendCreationError>` ### window **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#214 ```rust fn window(self, value: u32) -> Self ``` Set the number of most recent health check queries to keep. Must not be greater than 15. Defaults to 5. **Parameters** - `self`: `Self` - `value`: `u32` **Returns** `Self` ## Trait implementations ### impl Clone for HealthcheckBuilder #### clone **Source:** https://docs.rs/crate/fastly/0.13.1/source/src/experimental/dynamic_backend_healthchecks.rs#20 ```rust fn clone(&self) -> Self ``` **Parameters** - `self`: `&Self` **Returns** `Self` ## Auto trait implementations - `Freeze` - `RefUnwindSafe` - `Send` - `Sync` - `Unpin` - `UnsafeUnpin` - `UnwindSafe` ## Blanket implementations - `Any` - `Borrow` - `BorrowMut` - `CloneToUninit` - `Downcast` - `DowncastSync` - `ErasedDestructor` - `From` - `Into` - `IntoEither` - `Same` - `ToOwned` - `TryFrom` - `TryInto`