GRPC memory leak from opening session using empty with block #239
Description
Description
A basic session open/close example in docs has broken as of upgrading from client 2.2.0 to 2.4.0. The breakage comes from GRPC, seemingly because a resource wasn't closed properly. It's very suspicious that this only breaks for an empty with block, so I have named the issue as such.
Environment
- OS (where TypeDB server runs): Factory (not reproducible locally on Mac OS 10)
- TypeDB version (and platform): TypeDB 2.5
- TypeDB client-python version: client-python 2.5
- Python version: 3.6
Reproducible Steps
Steps to create the smallest reproducible scenario:
Run the docs tests in Factory, and most of the time the Python tests fail in this way:
INFO: Found 1 target...
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[0 / 1] [Prepa] BazelWorkspaceStatusAction stable-status.txt
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Target //test/example/python:social-network up-to-date:
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bazel-bin/test/example/python/social_network_quickstart_query.py
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bazel-bin/test/example/python/social_network_python_client_a.py
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bazel-bin/test/example/python/social_network_python_client_b.py
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bazel-bin/test/example/python/social_network_python_client_c.py
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bazel-bin/test/example/python/social_network_python_client_d.py
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bazel-bin/test/example/python/social-network
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INFO: Elapsed time: 0.842s, Critical Path: 0.51s
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INFO: 5 processes: 1 remote cache hit, 4 internal.
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INFO: Build completed successfully, 5 total actions
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INFO: Running command line: external/bazel_tools/tools/test/test-setup.sh test/example/python/social-network
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INFO: Build completed successfully, 5 total actions
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exec ${PAGER:-/usr/bin/less} "$0" || exit 1
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Executing tests from //test/example/python:social-network
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-----------------------------------------------------------------------------
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test_social_network_python_client_a (__main__.SocialNetworkTest) ... ok
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test_social_network_python_client_b (__main__.SocialNetworkTest) ... E1026 09:05:48.592246686 4855 metadata.cc:253] WARNING: 1 metadata elements were leaked
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E1026 09:05:48.592321591 4855 metadata.cc:260] mdelem 'user-agent' = 'grpc-python/1.38.0 grpc-c/16.0.0 (linux; chttp2)'
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E1026 09:05:48.592333692 4855 metadata.cc:253] WARNING: 1 metadata elements were leaked
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E1026 09:05:48.592339292 4855 metadata.cc:260] mdelem ':authority' = 'localhost:1729'
Investigating, test_social_network_python_client_b seems to be giving a warning of a leak.I presume that although this says "WARNING", given the lack of subsequent output, this is our culprit. The user-agent is grpc-python and the error codes seem consistent with issues on grpc: grpc/grpc#7121
The snippet of the docs being tested, social_network_python_client_b, is trivial and is as follows:
from typedb.client import *
with TypeDB.core_client("localhost:1729") as client:
with client.session("social_network", SessionType.DATA) as session:
## session is open
pass
## session is closed
## client is closedIt looks like this has been broken since commit fb4fbfed0c97f35ccd7984e637f6f6b4c2fcf023, which upgraded the python client dependency from 2.2.0 to 2.4.0.
Note that this issue is non-deterministic, I just re-ran the tests on Factory and they passed. I was also not able to reproduce this locally.
Expected Output
Session should close with no effect!
Actual Output
Memory leak and error from GRPC.