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vllm.snapshot.server

Classes:

Functions:

SnapshotBarrierError

Bases: RuntimeError

The controller supplied an invalid snapshot release marker.

Source code in vllm/snapshot/server.py 
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class SnapshotBarrierError(RuntimeError):
    """The controller supplied an invalid snapshot release marker."""

SnapshotCanaryError

Bases: RuntimeError

The initialized engine did not produce a valid snapshot oracle.

Source code in vllm/snapshot/server.py 
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class SnapshotCanaryError(RuntimeError):
    """The initialized engine did not produce a valid snapshot oracle."""

_release_reloadable_state(engine) async

Discard model and KV state before the process image is captured.

Source code in vllm/snapshot/server.py 
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async def _release_reloadable_state(engine: Any) -> None:
    """Discard model and KV state before the process image is captured."""
    await engine.sleep(level=2)

_restore_reloadable_state(engine) async

Rebuild state discarded by _release_reloadable_state.

Source code in vllm/snapshot/server.py 
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async def _restore_reloadable_state(engine: Any) -> None:
    """Rebuild state discarded by ``_release_reloadable_state``."""
    await engine.wake_up(tags=["weights"])
    await engine.collective_rpc("reload_weights")
    await engine.wake_up(tags=["kv_cache"])

detach_snapshot_streams()

Remove launch-log descriptors from the reusable process image.

Source code in vllm/snapshot/server.py 
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def detach_snapshot_streams() -> None:
    """Remove launch-log descriptors from the reusable process image."""
    sys.stdout.flush()
    sys.stderr.flush()
    sink = os.open(os.devnull, os.O_WRONLY)
    try:
        os.dup2(sink, sys.stdout.fileno())
        os.dup2(sink, sys.stderr.fileno())
    finally:
        os.close(sink)