Error - Access to impala data with impyla

Question

I am trying to connect impala with impyla and the following code.

from impala.dbapi import connect

# Set the connection parameters
host_name = "xxx.com"
port = 21050
database = "default"
user = "xxx"
password = "xxx"

connection_url = f"jdbc:impala://{host_name}:{port}/{database}"

# Connect to Impala
conn = connect(host=host_name,
               port=port,
               database=database,
               user=user,
               password=password,
              )

conn looks to be connected successfuly, but next code

cursor = conn.cursor()

returned

HiveServer2Error: Failed after retrying 3 times

If you know the problem, I hope to take advise what is the causation of this error and the method to check if truly conn is connected successfully.