Describe the bug, including details regarding any error messages, version, and platform.
A FlightServerBase, even after shutdown(), wait() and dropping the last user reference, doesn't seem to be completely freed. It stays alive and leaks.
Applications that create a Flight server per unit of work (one per build, per request batch, per test) accumulate one zombie server per cycle.
$ uv run python
Python 3.14.2 (main, Jan 14 2026, 19:38:07) [Clang 21.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import gc
... import pyarrow.flight as fl
...
... class Server(fl.FlightServerBase):
... pass
...
... for _ in range(100):
... server = Server("grpc://127.0.0.1:0")
... server.payload = bytearray(8 * 1024 * 1024)
... server.shutdown()
... server.wait()
... del server
... gc.collect()
...
... print(sum(1 for o in gc.get_objects() if isinstance(o, Server)))
...
100
>>> import pyarrow
>>> pyarrow.__version__
'25.0.0'RSS grows ~8 MB per iteration, tracking the payload one for one. The same loop with a plain Python object instead of a Flight server keeps RSS flat and prints 0.
Without a payload the loop still leaks about 66 kB RSS and 12 to 16 MB of virtual address space per iteration. An equivalent C++ loop creating and shutting down a Flight server shows no growth, so this points at an issue in the Python bindings.
Component(s)
FlightRPC, Python
Describe the bug, including details regarding any error messages, version, and platform.
A
FlightServerBase, even aftershutdown(),wait()and dropping the last user reference, doesn't seem to be completely freed. It stays alive and leaks.Applications that create a Flight server per unit of work (one per build, per request batch, per test) accumulate one zombie server per cycle.
RSS grows ~8 MB per iteration, tracking the payload one for one. The same loop with a plain Python object instead of a Flight server keeps RSS flat and prints
0.Without a payload the loop still leaks about 66 kB RSS and 12 to 16 MB of virtual address space per iteration. An equivalent C++ loop creating and shutting down a Flight server shows no growth, so this points at an issue in the Python bindings.
Component(s)
FlightRPC, Python