ConnectionError的终极解决办法就是重试，多重发几次就可以了。
具体见如下Python代码：

import requests
import json

url = "http://xxx.com/data.json"
# 重试最多5次
for i in range(5):
    try:
        with requests.get(url) as res:
            r = res.json()
            if len(r['data']) > 0:
                break
    except requests.exceptions.ConnectionError:
        print("ConnectionError")
        continue