资源编排：SDK常见问题

使用SDK时遇到报错ErrCode:SDK.ServerUnreachable怎么办？

当您使用SDK时，遇到以下报错信息（请求超时或服务器不可达）：

ErrCode:ServerUnreachable
ErrMsg:SocketTimeoutException has occurred on a socket read or accept.

1. 在请求中设置ClientToken参数避免多次重试带来重复操作的问题。

   Python示例代码如下：

   #!/usr/bin/env python
   # coding=utf-8
   import time
   import uuid
   
   from aliyunsdkcore.client import AcsClient
   from aliyunsdkcore.acs_exception.exceptions import ClientException, ServerException
   from aliyunsdkros.request.v20190910.CreateStackRequest import CreateStackRequest
   
   ACCESS_KEY_ID = ''
   ACCESS_KEY_SECRET = ''
   REGION_ID = 'cn-beijing'
   
   
   def generate_client_token(prefix, add_uuid, *suffix_list):
       if prefix:
           t = [prefix]
       else:
           t = []
       if add_uuid:
           t.append(str(uuid.uuid1())[:-13])
       t.extend(suffix_list)
       r = '_'.join(t)
       if len(r) > 64:
           r = r[:64]
       return r
   
   
   def retry_with_client_token(retry_interval=10, retry_time_out=300):
       def wrapper(fun):
           def retry_func(*args, **kwargs):
               retry_timeout = retry_time_out
               elapsed_time = 0
               # 保证请求的幂等性。该值由客户端生成，并且必须是全局唯一的。
               kwargs['ClientToken'] = generate_client_token(None, True)
               while True:
                   try:
                       retry_timeout -= elapsed_time
                       return fun(*args, **kwargs)
                   except Exception as e:
                       if isinstance(e, ClientException):
                           if e.error_code != 'SDK.HttpError':
                               raise
                       elif isinstance(e, ServerException):
                           if e.error_code not in ('LastTokenProcessing', 'ServiceUnavailable'):
                               raise
                       else:
                           raise
   
                       time.sleep(retry_interval)
                       elapsed_time += retry_interval
                       if elapsed_time >= retry_timeout:
                           raise
   
           return retry_func
   
       return wrapper
   
   
   class RosClient(object):
       def __init__(self):
           self.client = AcsClient(ACCESS_KEY_ID, ACCESS_KEY_SECRET, REGION_ID)
   
       def _send_request(self, request, params, **kwargs):
           request.set_accept_format('json')
           request.set_connect_timeout(10000)
           request.set_read_timeout(0.01)
           params.update(kwargs)
           for name, value in params.items():
               set_func = getattr(request, 'set_{}'.format(name))
               set_func(value)
           return self.client.do_action_with_exception(request)
   
       @retry_with_client_token(retry_interval=10, retry_time_out=300)
       def create_stack(self, params, **kwargs):
           request = CreateStackRequest()
           return self._send_request(request, params, **kwargs)
   
   
   if __name__ == '__main__':
       ros_client = RosClient()
       result = ros_client.create_stack(dict(
           StackName='test',
           TemplateBody="{\"ROSTemplateFormatVersion\": \"2015-09-01\"}"
       ))
       print('stack_id:', result)                  

2. 如果问题依然存在，请提交工单获取支持。