a bug was finded when create query_id for clickhouse where I use multiprocessing Pool

[crystalxiaoou]

Describe the bug
when I execute query statement from clickhouse by six Process Simultaneously. I get this error message:
【Orig exception: Code: 216, e.displayText() = DB::Exception: Query with id = cefe5212-cc01-11ea-b502-6c92bfbaaded is already running. (version 19.16.10.44)】

Then I find the six process create the same query_id in this code frame above:

https://github.com/xzkostyan/clickhouse-sqlalchemy/blob/08eb01c6b308aa6ba6b7827116a6a93beeeec5cb/clickhouse_sqlalchemy/drivers/http/connector.py

def _begin_query(self):
       self._state = self._states.RUNNING
        self._query_id = uuid1()

To Reproduce
when use multiprocessing.Pool() to create multi Process, uuid1() print the same uuid string。

import multiprocessing
import uuid

def myPrint():
    print(uuid.uuid1())

def test():
   pool = multiprocessing.Pool(5)
   tasks =[]
   tasks.append(pool.apply_async(myPrint))
   tasks.append(pool.apply_async(myPrint))
   tasks.append(pool.apply_async(myPrint))
   tasks.append(pool.apply_async(myPrint))
   tasks.append(pool.apply_async(myPrint))

   pool.close()
   pool.join()

   for task in tasks:
       task.get()


if __name__ == "__main__":
    test()

Result:

25b5ff20-cc24-11ea-ac37-acde48001122
25b61064-cc24-11ea-bbb8-acde48001122
25b5f7dc-cc24-11ea-9a4c-acde48001122
25b61ef6-cc24-11ea-8e7b-acde48001122

Expected behavior
I think that diffrent query_id should be create when call _begin_query() in https://github.com/xzkostyan/clickhouse-sqlalchemy/blob/08eb01c6b308aa6ba6b7827116a6a93beeeec5cb/clickhouse_sqlalchemy/drivers/http/connector.py

otherwise, clickhouse will return a error about "Query with id = cefe5212-cc01-11ea-b502-6c92bfbaaded is already running. (version 19.16.10.44)
"

Versions

• clickhouse-sqlalchemy : 0.1.2
• clickhouse : 19.16.10.44

Version of package with the problem

• Python version: 3.7

[xzkostyan]

Fixed in latest master. UUID1 replaced with UUID4.