PyODPS使用问题

File "./test_aliyun_mac7days.py", line 26, in UploadData

writer.write(record)

File "odps/tunnel/tabletunnel/writer_c.pyx", line 251, in odps.tunnel.tabletunnel.writer_c.BaseRecordWriter.__exit__ (odps/tunnel/tabletunnel/writer_c.c:7636)
File "odps/tunnel/tabletunnel/writer_c.pyx", line 239, in odps.tunnel.tabletunnel.writer_c.BaseRecordWriter.close (odps/tunnel/tabletunnel/writer_c.c:7295)
File "/usr/local/lib/python2.7/site-packages/odps/tunnel/tabletunnel/writer.py", line 278, in close

self._req_io.finish()

File "/usr/local/lib/python2.7/site-packages/odps/tunnel/io.py", line 94, in finish

self._wait_obj.join()

File "/usr/local/lib/python2.7/threading.py", line 652, in join

raise RuntimeError("cannot join thread before it is started")

RuntimeError: cannot join thread before it is started

很奇怪，类似的代码一直在跑都没问题。已有一个进程a正在向表A传数据，今天新增了一个程序b，上传到另一个表B，进程b出现上面这个错误。用了logging 其中有这样的日志

2017-06-21 17:07:18 - Starting new HTTP connection (1): dt.odps.aliyun.com
2017-06-21 17:07:23 - "POST /projects/mac_scan/tables/xaa170621?uploads=1&curr_project=mac_scan HTTP/1.1" 201 931
2017-06-21 17:07:23 - response.status_code 201