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sqlalchemy object caching issue

See original GitHub issue

Greetings! I ran into sqlalchemy object caching issues. From time to time I get errors like this:

"  File \"/home/boot/stellar/backend/./app/v1/security/auth.py\", line 127, in get_current_user\n    permissions_v2 = await service_permissions.get_permissions_by_role_cache(\n",
      "  File \"/home/boot/stellar/backend/.venv/lib/python3.10/site-packages/cashews/wrapper.py\", line 272, in _call\n    return await decorator(*args, **kwargs)\n",
      "  File \"/home/boot/stellar/backend/.venv/lib/python3.10/site-packages/cashews/decorators/cache/simple.py\", line 43, in _wrap\n    await backend.set(_cache_key, result, expire=ttl)\n",
      "  File \"/home/boot/stellar/backend/.venv/lib/python3.10/site-packages/cashews/validation.py\", line 62, in _invalidate_middleware\n    return await call(*args, key=key, **kwargs)\n",
      "  File \"/home/boot/stellar/backend/.venv/lib/python3.10/site-packages/cashews/wrapper.py\", line 34, in _auto_init\n    return await call(*args, **kwargs)\n",
      "  File \"/home/boot/stellar/backend/.venv/lib/python3.10/site-packages/cashews/disable_control.py\", line 12, in _is_disable_middleware\n    return await call(*args, **kwargs)\n",
      "  File \"/home/boot/stellar/backend/.venv/lib/python3.10/site-packages/cashews/backends/client_side.py\", line 132, in set\n    return await super().set(self._prefix + key, value, *args, **kwargs)\n",
      "  File \"/home/boot/stellar/backend/.venv/lib/python3.10/site-packages/cashews/serialize.py\", line 107, in set\n    value = pickle.dumps(value, protocol=pickle.HIGHEST_PROTOCOL, fix_imports=False)\n",
      "_pickle.PicklingError: Can't pickle <function __init__ at 0x7fc386fbb7f0>: it's not the same object as sqlalchemy.orm.instrumentation.__init__\n"

I found the answer that such objects should be serialized and deserialized differently: https://docs.sqlalchemy.org/en/14/core/serializer.html

Tell me how good / bad idea it is to cache alchemy objects, and not the endpoint itself.

If this is not bad, what can you say about adding functionality that could fix this error?

Issue Analytics

State:
Created a year ago
Comments:13 (8 by maintainers)

Top GitHub Comments

2reactions

Krukovcommented, Jul 26, 2022

Hello,

I think objects like sqlalchemy orm is a good use case for caching, if it possible to pickle somehow. So Yep, cashews should support it ( thanks for the link), I am going to fix this issue ASAP.

1reaction

Krukovcommented, Sep 30, 2022

released with 4.7.1

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