Default implementation of the options to Hardhat.Middleware.DeadlinePropagation that is included in the default middleware stack.

These defaults include:

• :header - "deadline" is the name of the header added to the request

Default implementation of the options to the Tesla.Middleware.Fuse that is included in the default middleware stack.

Takes the client module name as an argument.

These defaults include:

• :opts - The fuse will blow after 50 errors with 1 second, and reset after 2 seconds
• :keep_original_error - The original error will be returned when a fuse first blows
• :should_melt - The should_melt/1 function defined in the client module is used (by default this is Hardhat.Defaults.should_melt/1)
• :mode - The fuse uses :async_dirty mode to check the failure rate, which may result in some delay in blowing the fuse under high concurrency, but it will not serialize checks to the fuse state through a single process

See Tesla.Middleware.Fuse for more information on how to configure the middleware.

The default options for the connection pool that will be created when your client is added to the supervision tree.

This creates a connection pool of size 10.

Default options for the Regulator middleware, which can be used as an alternative circuit-breaking strategy to :fuse.

The defaults include:

• :min_limit - The minimum concurrency limit (defaults to 5)
• :initial_limit - The initial concurrency limit when the regulator is installed (deafults to 20)
• :max_limit - The maximum concurrency limit (defaults to 200)
• :step_increase - The number of tokens to add when regulator is increasing the concurrency limit (defaults to 10).
• :backoff_ratio - Floating point value for how quickly to reduce the concurrency limit (defaults to 0.9)
• :target_avg_latency - This is the average latency in milliseconds for the system regulator is protecting. If the average latency drifts above this value Regulator considers it an error and backs off. Defaults to 5.
• :should_regulate - Whether to consider the result of the request as failed, defaults to should_regulate/1.

Default implementation of the options to Tesla.Middleware.Retry that is included in the default middleware stack.

These defaults include:

• :delay - The base delay in milliseconds (positive integer, defaults to 50)
• :max_retries - maximum number of retries (non-negative integer, defaults to 3)
• :max_delay - maximum delay in milliseconds (positive integer, defaults to 300)
• :should_retry - function to determine if request should be retried, defaults to should_retry/1
• :jitter_factor - additive noise proportionality constant (float between 0 and 1, defaults to 0.2)

Default implementation of the "melt test" for circuit breaking. This function will cause the circuit breaker to record an error when the result of a request is:

• A TCP-level error, e.g. {:error, :econnrefused}
• An HTTP status that indicates a server error or proxy-level error (>= 500)
• An 429 Too Many Requests HTTP status

Default implementation of the "failure test" for dynamic regulation. This function will cause the Regulator to record an error when the result of a request is:

• A TCP-level error, e.g. {:error, :econnrefused}
• An HTTP status that indicates a server error or proxy-level error (>= 500)
• An 429 Too Many Requests HTTP status

Default implementation of the "retry test" for retries. This function will cause requests to be retried when the result of the request is:

• A TCP-level error, e.g. {:error, :econnrefused}
• An HTTP status that indicates a server error or proxy-level error (>= 500)
• An 429 Too Many Requests HTTP status

In the case where the circuit breaker has been triggered, requests will not be retried.