如何避免 selenium webdriver 的套接字超时？

Question

我有一个复杂的 python-selenium 测试套件来测试非公共网页。在该设置中，我需要获取如下所示的 webdriver：

self.driver = webdriver.Firefox(firefox_profile = profile, log_path = logfile)

带有一些配置文件和日志路径。在大多数情况下，这行代码工作正常，但有时（5％或这种情况）我收到套接字超时错误：

File "/root/tests/usecase_tests/tools/basicsuite.py", line 213, in set_driver_firefox
    self.driver = webdriver.Firefox(firefox_profile = profile, log_path = logfile)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/firefox/webdriver.py", line 158, in __init__
    keep_alive=True)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 154, in __init__
    self.start_session(desired_capabilities, browser_profile)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 243, in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py", line 309, in execute
    response = self.command_executor.execute(driver_command, params)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/remote_connection.py", line 460, in execute
    return self._request(command_info[0], url, body=data)
  File "/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/remote_connection.py", line 484, in _request
    resp = self._conn.getresponse()
  File "/usr/lib/python2.7/httplib.py", line 1136, in getresponse
    response.begin()
  File "/usr/lib/python2.7/httplib.py", line 453, in begin
    version, status, reason = self._read_status()
  File "/usr/lib/python2.7/httplib.py", line 409, in _read_status
    line = self.fp.readline(_MAXLINE + 1)
  File "/usr/lib/python2.7/socket.py", line 480, in readline
    data = self._sock.recv(self._rbufsize)
timeout: timed out

此错误的可能原因是什么？如何调试这个错误？如何解决？

Answer 1

该错误说明了一切：

  File "/usr/lib/python2.7/socket.py", line 480, in readline
    data = self._sock.recv(self._rbufsize)
timeout: timed out

事件顺序

以下是事件发生的顺序：

• 最初错误发生在basicsuite.py文件中的以下行：

  self.driver = webdriver.Firefox(firefox_profile = profile, log_path = logfile)
  

• 经过一系列检查后，最终调用了以下方法，但失败了：

  def readinto(self, b):
  """Read up to len(b) bytes into the writable buffer *b* and return
  the number of bytes read.  If the socket is non-blocking and no bytes
  are available, None is returned.
  
  If *b* is non-empty, a 0 return value indicates that the connection
  was shutdown at the other end.
  """
  self._checkClosed()
  self._checkReadable()
  if self._timeout_occurred:
      raise OSError("cannot read from timed out object")
  while True:
      try:
      return self._sock.recv_into(b)
      except timeout:
      self._timeout_occurred = True
      raise
      except error as e:
      if e.args[0] in _blocking_errnos:
          return None
      raise
  

• 程序错误出现在：

  self._sock.recv(b) # where If *b* is non-empty, a 0 return value indicates that the connection was shutdown at the other end.
  

结论

结论是，建立连接的尝试未成功，这意味着实例的初始化webdriver以及新Mozilla Firefox浏览器会话的进一步生成均未成功。

分析

不可能得出timeout: timed out发生的真正原因。但您可以遵循以下一些最佳实践：

• 提供日志文件的完整名称以及logical location日志文件的名称（来自项目级别），如下所示：

  self.driver = webdriver.Firefox(firefox_profile=profile, log_path='./Log/geckodriver.log')
  

• 始终quit()在tearDown()方法中使用，以便正确销毁webdriver和 两者。webclient

• 在启动之前Test Execution，请确保系统中Task Manager没有悬空的实例GeckoDriver或进程。Firefox

• 确保您使用的二进制版本JDK、Selenium、GeckoDriver、Mozilla Firefox Browser兼容。您可以在此 QA 中找到详细的讨论Selenium WebDriver 3.4.0 + geckodriver 0.18.0 + Firefox ?? - which combination works?

• 在执行.Project Workspace​Test Suite

• CCleaner定期使用工具来清除操作系统的杂务。

• 如果 的基本版本Firefox Browser太旧，请卸载Firefox Browser并Revo Uninstaller安装Moderate Scan最新GA-Released版本的Firefox Browser。