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Restart

RestartSpec dataclass

Specification for how a Service should handle restarts and budget exhaustion.

Attach to a :class:Service subclass as a class attribute::

class MyService(Service):
    restart_spec = RestartSpec(restart_type=RestartType.PERMANENT)
Source code in src/hassette/resources/restart.py 
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@dataclass(frozen=True)
class RestartSpec:
    """Specification for how a Service should handle restarts and budget exhaustion.

    Attach to a :class:`Service` subclass as a class attribute::

        class MyService(Service):
            restart_spec = RestartSpec(restart_type=RestartType.PERMANENT)
    """

    restart_type: RestartType = RestartType.TRANSIENT
    """Strategy governing restart and budget-exhaustion behavior."""

    non_retryable_error_names: tuple[str, ...] = ()
    """Exception type names that skip restart and follow the budget-exhaustion path directly."""

    fatal_error_names: tuple[str, ...] = ()
    """Exception type names that always trigger immediate shutdown regardless of restart_type."""

    backoff_base_seconds: float = 2.0
    """Base seconds for exponential backoff between restart attempts."""

    backoff_multiplier: float = 2.0
    """Multiplier applied to backoff on each successive restart attempt."""

    backoff_max_seconds: float = 60.0
    """Maximum backoff delay in seconds."""

    budget_intensity: int = 5
    """Maximum number of restarts allowed within the budget window."""

    budget_period_seconds: float = 300.0
    """Sliding window size in seconds for the restart budget."""

    startup_timeout_seconds: float = 30.0
    """How long to wait for mark_ready() after a restart before considering it failed."""

    cooldown_seconds: float = 300.0
    """Duration in seconds for the long-cooldown phase (TRANSIENT services only)."""

    max_cooldown_cycles: int = 0
    """Maximum cooldown cycles before transitioning to EXHAUSTED_DEAD. 0 = infinite."""

restart_type: RestartType = RestartType.TRANSIENT class-attribute instance-attribute

Strategy governing restart and budget-exhaustion behavior.

non_retryable_error_names: tuple[str, ...] = () class-attribute instance-attribute

Exception type names that skip restart and follow the budget-exhaustion path directly.

fatal_error_names: tuple[str, ...] = () class-attribute instance-attribute

Exception type names that always trigger immediate shutdown regardless of restart_type.

backoff_base_seconds: float = 2.0 class-attribute instance-attribute

Base seconds for exponential backoff between restart attempts.

backoff_multiplier: float = 2.0 class-attribute instance-attribute

Multiplier applied to backoff on each successive restart attempt.

backoff_max_seconds: float = 60.0 class-attribute instance-attribute

Maximum backoff delay in seconds.

budget_intensity: int = 5 class-attribute instance-attribute

Maximum number of restarts allowed within the budget window.

budget_period_seconds: float = 300.0 class-attribute instance-attribute

Sliding window size in seconds for the restart budget.

startup_timeout_seconds: float = 30.0 class-attribute instance-attribute

How long to wait for mark_ready() after a restart before considering it failed.

cooldown_seconds: float = 300.0 class-attribute instance-attribute

Duration in seconds for the long-cooldown phase (TRANSIENT services only).

max_cooldown_cycles: int = 0 class-attribute instance-attribute

Maximum cooldown cycles before transitioning to EXHAUSTED_DEAD. 0 = infinite.