rest server centos 7 and python 3 doesnt seem work well - linux

Question

I have a rest server that i use it in the my main program ; rest server is running on centos 7 vps when i run the main on my laptop which is windows 7 it works as well; but when i run the main as a service on the same vps server it doesn't work well i've checked every single possible problems even changing unicode but i wouldn't find a solution yet.
here is my rest server code:
from bottle import route, run, redirect
import sqlite3
db = sqlite3.connect("checkLink.db")
db.execute("DROP TABLE IF EXISTS checkLink")
db.execute("CREATE TABLE checkLink(user_id INT, link TEXT, join_link TEXT,
check_id INT)")
db.execute("CREATE UNIQUE INDEX user_id ON checkLink(user_id, link,
join_link, check_id)")
db.commit()
def database(user_id, link):
db2 = sqlite3.connect("checkLink.db")
db2.row_factory = sqlite3.Row
cursor = db2.execute("SELECT * FROM checkLink WHERE user_id=? AND link=?",
(user_id, link))
db2.commit()
for row in cursor:
check_id = row["check_id"]
if check_id == 1:
return 1
else:
return 0
def database_insert(user_id, link):
db2 = sqlite3.connect("checkLink.db")
db2.execute("INSERT INTO checkLink(user_id, link, join_link, check_id)
VALUES (?,?,?,?)", (user_id, link,
"http://my link", 1))
db2.commit()
#route('/<link>/<chat_id>')
def index(link, chat_id):
check = database(chat_id, link)
if check != 1:
database_insert(chat_id, link)
redirect("https://my link")
#route('/redirect')
def index():
redirect("https://my link")
#route('/check/<link>/<chat_id>')
def index(link, chat_id):
check = database(chat_id, link)
if check == 1:
return {"id": chat_id, "permission": "True"}
else:
return {"id": chat_id, "permission": "False"}
run(host='my ip', port=my port)