parse_response error in ThreadPoolExecutor when setting single_connection_client = True

[zyp-rgb]

Version: redis-py 3.5.3, docker redislabs/rejson:1.0.4

Platform: Python 3.8.2 on mac

Description: parse_response error in threadpoolexecutor when setting single_connection_client = True

The following code reports random errors. When changing the setting single_connection_client to False, it runs okay.

import traceback
import concurrent.futures
from redis import StrictRedis

client = StrictRedis(host='redis', port=6379, db=0, decode_responses=True,
                     single_connection_client=True)

# Retrieve a single page and report the URL and contents
def redis_handler(value: int):
  a = client.zadd('test', {value: value * 2.2})
  b = client.zscore('test', value)
  c = client.set(f'test:{value}', value)
  d = client.get(f'test:{value}')
  return a, b, c, d


if __name__ == '__main__':
  # We can use a with statement to ensure threads are cleaned up promptly
  with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
      # Start the load operations and mark each future with its URL
      future_redis_handle = {executor.submit(redis_handler, i): idx for idx, i in
                       enumerate(range(100))}
      future_redis_handle.update(
          {executor.submit(redis_handler, i): idx + 100 for idx, i in
           enumerate(range(100))})

      for future in concurrent.futures.as_completed(future_redis_handle):
          idx = future_redis_handle[future]
          try:
              data = future.result()
          except Exception as exc:
            print(
              f'generated an exception: {(idx, exc, traceback.format_exc())}')
          else:
            print(f'page is bytes {(idx, data)}')

some error samples

 (45, ValueError("invalid literal for int() with base 10: '94.600000000000009'"), 'Traceback (most recent call last):\n  File "test_redis_problem.py", line 30, in <module>\n    data = future.result()\n  File "/usr/local/lib/python3.8/concurrent/futures/_base.py", line 432, in result\n    return self.__get_result()\n  File "/usr/local/lib/python3.8/concurrent/futures/_base.py", line 388, in __get_result\n    raise self._exception\n  File "/usr/local/lib/python3.8/concurrent/futures/thread.py", line 57, in run\n    result = self.fn(*self.args, **self.kwargs)\n  File "test_redis_problem.py", line 10, in redis_handler\n    a = client.zadd(\'test\', {value: value * 2.2})\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 2688, in zadd\n    return self.execute_command(\'ZADD\', name, *pieces, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 901, in execute_command\n    return self.parse_response(conn, command_name, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 921, in parse_response\n    return self.response_callbacks[command_name](response, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 380, in parse_zadd\n    return int(response)\nValueError: invalid literal for int() with base 10: \'94.600000000000009\'\n')

generated an exception: (51, ValueError("invalid literal for int() with base 10: 'OK'"), 'Traceback (most recent call last):\n  File "test_redis_problem.py", line 30, in <module>\n    data = future.result()\n  File "/usr/local/lib/python3.8/concurrent/futures/_base.py", line 432, in result\n    return self.__get_result()\n  File "/usr/local/lib/python3.8/concurrent/futures/_base.py", line 388, in __get_result\n    raise self._exception\n  File "/usr/local/lib/python3.8/concurrent/futures/thread.py", line 57, in run\n    result = self.fn(*self.args, **self.kwargs)\n  File "test_redis_problem.py", line 10, in redis_handler\n    a = client.zadd(\'test\', {value: value * 2.2})\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 2688, in zadd\n    return self.execute_command(\'ZADD\', name, *pieces, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 901, in execute_command\n    return self.parse_response(conn, command_name, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 921, in parse_response\n    return self.response_callbacks[command_name](response, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 380, in parse_zadd\n    return int(response)\nValueError: invalid literal for int() with base 10: \'OK\'\n')

generated an exception: (54, ValueError("invalid literal for int() with base 10: 'OK'"), 'Traceback (most recent call last):\n  File "test_redis_problem.py", line 30, in <module>\n    data = future.result()\n  File "/usr/local/lib/python3.8/concurrent/futures/_base.py", line 432, in result\n    return self.__get_result()\n  File "/usr/local/lib/python3.8/concurrent/futures/_base.py", line 388, in __get_result\n    raise self._exception\n  File "/usr/local/lib/python3.8/concurrent/futures/thread.py", line 57, in run\n    result = self.fn(*self.args, **self.kwargs)\n  File "test_redis_problem.py", line 10, in redis_handler\n    a = client.zadd(\'test\', {value: value * 2.2})\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 2688, in zadd\n    return self.execute_command(\'ZADD\', name, *pieces, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 901, in execute_command\n    return self.parse_response(conn, command_name, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 921, in parse_response\n    return self.response_callbacks[command_name](response, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 380, in parse_zadd\n    return int(response)\nValueError: invalid literal for int() with base 10: \'OK\'\n')
generated an exception: (55, AttributeError("'NoneType' object has no attribute 'readline'"), 'Traceback (most recent call last):\n  File "test_redis_problem.py", line 30, in <module>\n    data = future.result()\n  File "/usr/local/lib/python3.8/concurrent/futures/_base.py", line 432, in result\n    return self.__get_result()\n  File "/usr/local/lib/python3.8/concurrent/futures/_base.py", line 388, in __get_result\n    raise self._exception\n  File "/usr/local/lib/python3.8/concurrent/futures/thread.py", line 57, in run\n    result = self.fn(*self.args, **self.kwargs)\n  File "test_redis_problem.py", line 11, in redis_handler\n    b = client.zscore(\'test\', value)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 2958, in zscore\n    return self.execute_command(\'ZSCORE\', name, value)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 901, in execute_command\n    return self.parse_response(conn, command_name, **options)\n  File "/usr/local/lib/python3.8/site-packages/redis/client.py", line 915, in parse_response\n    response = connection.read_response()\n  File "/usr/local/lib/python3.8/site-packages/redis/connection.py", line 739, in read_response\n    response = self._parser.read_response()\n  File "/usr/local/lib/python3.8/site-packages/redis/connection.py", line 324, in read_response\n    raw = self._buffer.readline()\nAttributeError: \'NoneType\' object has no attribute \'readline\'\n')

[andymccurdy]

single_connection_client is not thread safe.

[zyp-rgb]

single_connection_client is not thread safe.

Okay thanks