python - OrientDB Gremlin 服务器不能在 python 中工作

Question

我在 python 中使用 orientdb 和 gremlin 服务器，Gremlin 服务器已成功启动，但是当我尝试通过 gremlin 代码向 orientdb 添加一个顶点时，它给我一个错误。

query = """graph.addVertex(label, "Test", "title", "abc", "title", "abc")"""

回溯如下

/usr/bin/python3.6 /home/admin-12/Documents/bitbucket/ecodrone/ecodrone/test/test1.py
Traceback (most recent call last):
  File "/home/admin-12/Documents/bitbucket/ecodrone/ecodrone/test/test1.py", line 27, in <module>
    result = execute_query("""graph.addVertex(label, "Test", "title", "abc", "title", "abc")""")
  File "/home/admin-12/Documents/bitbucket/ecodrone/ecodrone/GremlinConnector.py", line 21, in execute_query
    results = future_results.result()
  File "/usr/lib/python3.6/concurrent/futures/_base.py", line 432, in result
    return self.__get_result()
  File "/usr/lib/python3.6/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "/home/admin-12/.local/lib/python3.6/site-packages/gremlin_python/driver/resultset.py", line 81, in cb
    f.result()
  File "/usr/lib/python3.6/concurrent/futures/_base.py", line 425, in result
    return self.__get_result()
  File "/usr/lib/python3.6/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "/usr/lib/python3.6/concurrent/futures/thread.py", line 56, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/home/admin-12/.local/lib/python3.6/site-packages/gremlin_python/driver/connection.py", line 77, in _receive
    self._protocol.data_received(data, self._results)
  File "/home/admin-12/.local/lib/python3.6/site-packages/gremlin_python/driver/protocol.py", line 106, in data_received
    "{0}: {1}".format(status_code, data["status"]["message"]))
gremlin_python.driver.protocol.GremlinServerError: 599: Error during serialization: Infinite recursion (StackOverflowError) (through reference chain: com.orientechnologies.orient.core.id.ORecordId["record"]->com.orientechnologies.orient.core.record.impl.ODocument["schemaClass"]->com.orientechnologies.orient.core.metadata.schema.OClassImpl["document"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"]->com.orientechnologies.orient.core.record.impl.ODocument["owners"])

Process finished with exit code 1

Answer 1

首先，我非常建议大家不要使用Graph API来做mutation。为此首选 Traversal API 并执行以下操作:

g.addV('Test').
  property('title1', 'abc').
  property('title2', 'abc')

其次，我认为您的错误发生是因为您正在返回一个 Vertex，其中包含一个 ORecordId，它是顶点标识符，而 Gremlin 服务器不知道如何处理那个。我不知道 OrientDB 是否有序列化程序来处理这个问题，但如果有，那么你会想要 add them to Gremlin Server更详细描述的配置here - 基本上，您想知道 OrientDB 是否为所有可能通过网络发回的自定义类公开了 TinkerPop IORegistry。

如果他们不这样做，那么您可能希望避免退回这些内容或自行转换它们。 TinkerPop 已经建议您不要返回完整的 Vertex 对象，而只返回您需要的数据。因此，与其使用 g.V()，不如使用 g.V().valueMap('title ') 或类似的东西(也许使用 project() 步骤)。如果您确实需要顶点标识符，那么您需要将其转换为 TinkerPop 序列化程序可以理解的内容。这可能意味着一些简单的事情:

g.V().has("title1","abc").id().next().toString()