重启 Monitor 实例答案

【问题标题】：Restarting a Monitor instance重启 Monitor 实例
【发布时间】：2016-03-01 09:42:27
【问题描述】：

我有一个带有 Monitor 实例的cherrypy 应用，如下所示：

        mail_checker = Monitor(cherrypy.engine, self.mail_processor.poll_history_feed, frequency=10)

简单地说，它会检查 gmail 收件箱中的新电子邮件并进行处理。有时 poll_history_feed() 会抛出异常，我现在猜测这是因为我们的互联网不稳定，它会停止运行，直到我重新启动整个应用程序。（下面的回溯示例）

    [01/Mar/2016:17:08:29] ENGINE Error in background task thread function <bound method MailProcessor.poll_history_feed of <mailservices.mailprocessor.MailProcessor object at 0x10a2f0250>>.
Traceback (most recent call last):
  File "/Users/hashtaginteractive/Projects/.venvs/emaild/lib/python2.7/site-packages/cherrypy/process/plugins.py", line 500, in run
    self.function(*self.args, **self.kwargs)
  File "/Users/hashtaginteractive/Projects/emaild/emaild-source/mailservices/mailprocessor.py", line 12, in poll_history_feed
    labelIds=["INBOX", "UNREAD"]
  File "/Users/hashtaginteractive/Projects/.venvs/emaild/lib/python2.7/site-packages/oauth2client/util.py", line 142, in positional_wrapper
    return wrapped(*args, **kwargs)
  File "/Users/hashtaginteractive/Projects/.venvs/emaild/lib/python2.7/site-packages/googleapiclient/http.py", line 730, in execute
    return self.postproc(resp, content)
  File "/Users/hashtaginteractive/Projects/.venvs/emaild/lib/python2.7/site-packages/googleapiclient/model.py", line 207, in response
    return self.deserialize(content)
  File "/Users/hashtaginteractive/Projects/.venvs/emaild/lib/python2.7/site-packages/googleapiclient/model.py", line 262, in deserialize
    content = content.decode('utf-8')
  File "/Users/hashtaginteractive/Projects/.venvs/emaild/lib/python2.7/encodings/utf_8.py", line 16, in decode
    return codecs.utf_8_decode(input, errors, True)
UnicodeDecodeError: 'utf8' codec can't decode byte 0x8b in position 23: invalid start byte

有没有办法设置它，以便在发生异常时自动重新启动服务器或这个特定的 Monitor 实例？

【问题讨论】：

标签： python-2.7 cherrypy

【解决方案1】：

为了方便起见，您必须将对 self.mail_processor.poll_history_feed 的调用包装在 try/except 块中并记录错误。

def safe_poll_history_feed(self):
    try:
        self.mail_processor.poll_history_feed()
    except Exception:
        cherrypy.engine.log("Exception in mailprocessor monitor", traceback=True)

然后使用safe_poll_history_feed方法

【讨论】：