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--Import Circuit breaker factory.
local circuit_breaker_lib = require "lua-circuit-breaker.factory"

--Create a new instance of the circuit breaker factory. Always set version = 0. This is used for flushing the circuit breakers when the configuration is changed.
local circuit_breakers = circuit_breaker_lib:new()

-- Get a circuit breaker instance from factory. Returns a new instance only if not already created.
local settings = {
    version = 1,
    window_time = 10,
    min_calls_in_window= 20,
    failure_percent_threshold= 51,
    wait_duration_in_open_state= 15,
    wait_duration_in_half_open_state= 120,
    half_open_max_calls_in_window= 10,
    half_open_min_calls_in_window= 5,
    notify = function(name, state)
        print(string.format("Breaker [ %s ] state changed to [ %s ]", name, state))
    end,
}
local cb, err = circuit_breakers:get_circuit_breaker(
    "io_call_x", -- Name of circuit breaker. This should be unique.
    "io_calls", -- Used to group certain CB objects into one.
    settings,
)

-- Check state of cb. This function returns an error if the state is open or half_open_max_calls_in_window is breached.
local _, err_cb = cb:_before()
if err_cb then
    return false, "Circuit breaker open error"
end
local generation = cb._generation

-- Call IO method for which circuit breaking is required.
local res, err_http = makeIOCall()

-- Update the state of the cb based on successful / failure response.
local ok = res and res.status and res.status < 500
cb:_after(generation, ok) -- generation is used to update the counter in the correct time bucket.