Per-exchange circuit breakers using the :fuse Erlang library.
Prevents cascade failures when exchanges are down. Each exchange has isolated state — binance down does not affect bybit.
How It Works
- Each exchange gets its own fuse named
:ccxt_fuse_<exchange_id> - Fuses are installed lazily on first request
- After N failures within M milliseconds, the circuit opens
- Opened circuits reject requests immediately (fast fail)
- After reset timeout, circuit closes and allows requests again
What Triggers the Circuit
| Response | Melts? | Reason |
|---|---|---|
| HTTP 500+ | Yes | Server error |
| Timeouts | Yes | Server unresponsive |
| Connection refused | Yes | Server unavailable |
| HTTP 429 | No | Handled by rate limiter |
| HTTP 4xx | No | Client error, not server issue |
Configuration
config :ccxt_client, :circuit_breaker,
enabled: true,
max_failures: 5,
window_ms: 10_000,
reset_ms: 15_000Summary
Functions
Returns status of all installed circuit breakers.
Checks if requests are allowed for an exchange.
Returns circuit breaker configuration.
Records a failed request. Enough melts within the window opens the circuit.
Records the result of a request using should_melt?/1 logic.
Records a successful request. Success prevents further melts.
Resets a circuit breaker for an exchange.
Resets a circuit breaker, raising on error.
Determines if a response should trip the circuit breaker.
Returns the status of a circuit breaker for an exchange.
Functions
@spec all_statuses() :: %{required(String.t()) => :ok | :blown}
Returns status of all installed circuit breakers.
@spec check(String.t()) :: :ok | :blown
Checks if requests are allowed for an exchange.
Installs the fuse lazily if not already installed.
@spec config() :: %{ enabled: boolean(), max_failures: pos_integer(), window_ms: pos_integer(), reset_ms: pos_integer() }
Returns circuit breaker configuration.
@spec record_failure(String.t()) :: :ok
Records a failed request. Enough melts within the window opens the circuit.
Records the result of a request using should_melt?/1 logic.
Pass the raw result from Req ({:ok, %Req.Response{}} or {:error, reason}).
@spec record_success(String.t()) :: :ok
Records a successful request. Success prevents further melts.
@spec reset(String.t()) :: :ok | {:error, :not_found}
Resets a circuit breaker for an exchange.
@spec reset!(String.t()) :: :ok
Resets a circuit breaker, raising on error.
Determines if a response should trip the circuit breaker.
Melts on: HTTP 500+, transport errors. Does NOT melt on: HTTP 429, HTTP 4xx, successful responses.
@spec status(String.t()) :: :ok | :blown | :not_installed
Returns the status of a circuit breaker for an exchange.
:ok— circuit closed, requests allowed:blown— circuit open, requests rejected:not_installed— no fuse yet (no requests made)