Drain Marker Policy • AI Agent SDK

DrainMarkerPolicy

Defined in the protocols module.

AI Agent

Pure predicate deciding whether an external drain marker is actionable.

A drain marker is a small JSON object written by an operator / deploy step (via praisonai gateway drain) into a well-known path. A background watcher in the wrapper reads it and asks this policy whether the running gateway should react. The decision is intentionally side-effect free so it is provable in isolation without a live gateway or filesystem.

A marker is honoured only when it requests a drain for the current instantiation:

a missing marker (None) is never a drain request;

a marker carrying no epoch is treated as foreign and ignored, so a hand-rolled or legacy file cannot wedge a process;

a marker whose epoch differs from current_epoch is stale — it survived a reboot/restart on a durable volume — and is ignored;

a current-epoch marker is honoured (subject to an optional already-handled de-duplication via last_handled_epoch).

Example::

policy = DrainMarkerPolicy()
if policy.drain_requested(read_marker(), current_epoch(), monotonic()):
    await gateway.stop(drain_timeout=cfg.gateway.drain_timeout)

Return whether marker is a live drain request for this instance.

Guide

Reference

Drain Marker Policy • AI Agent SDK

DrainMarkerPolicy

Methods

drain_requested()

Source

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​DrainMarkerPolicy

​Methods

drain_requested()

​Source

View on GitHub

DrainMarkerPolicy

Methods

Source