Description of problem:
test_established_tcp_session_after_re_attachinging_sg failed

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/neutron_tempest_plugin/scenario/test_security_groups.py", line 300, in test_established_tcp_session_after_re_attachinging_sg
    con.test_connection()
  File "/usr/lib/python3.6/site-packages/neutron_tempest_plugin/common/utils.py", line 205, in __exit__
    self.server_ssh.exec_command('sudo killall tail || killall tail')
  File "/usr/lib/python3.6/site-packages/tenacity/__init__.py", line 292, in wrapped_f
    return self.call(f, *args, **kw)
  File "/usr/lib/python3.6/site-packages/tenacity/__init__.py", line 358, in call
    do = self.iter(retry_state=retry_state)
  File "/usr/lib/python3.6/site-packages/tenacity/__init__.py", line 319, in iter
    return fut.result()
  File "/usr/lib64/python3.6/concurrent/futures/_base.py", line 425, in result
    return self.__get_result()
  File "/usr/lib64/python3.6/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "/usr/lib/python3.6/site-packages/tenacity/__init__.py", line 361, in call
    result = fn(*args, **kwargs)
  File "/usr/lib/python3.6/site-packages/neutron_tempest_plugin/common/ssh.py", line 178, in exec_command
    return super(Client, self).exec_command(cmd=cmd, encoding=encoding)
  File "/usr/lib/python3.6/site-packages/tempest/lib/common/ssh.py", line 211, in exec_command
    stderr=err_data, stdout=out_data)
neutron_tempest_plugin.common.utils.SSHExecCommandFailed: Command 'sudo killall tail || killall tail' failed, exit status: 1, stderr:
tail: no process found
tail: no process found

stdout:


Version-Release number of selected component (if applicable):


How reproducible:


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Actual results:


Expected results:


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