我在减少步骤中遇到这样的错误。 MapReduce Overview页面报告所有作业都已成功完成，但我写入的一半记录未写入。导致此错误的原因是什么，我该如何解决？：
ApplicationError: 10
Traceback (most recent call last):
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1511, in __call__
rv = self.handle_exception(request, response, e)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1505, in __call__
rv = self.router.dispatch(request, response)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1253, in default_dispatcher
return route.handler_adapter(request, response)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1077, in __call__
return handler.dispatch()
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 547, in dispatch
return self.handle_exception(e, self.app.debug)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 545, in dispatch
return method(*args, **kwargs)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/base_handler.py", line 65, in post
self.handle()
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/handlers.py", line 181, in handle
entity, input_reader, ctx, tstate)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/handlers.py", line 298, in process_data
output_writer.write(output, ctx)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/output_writers.py", line 693, in write
ctx.get_pool("records_pool").append(str(data))
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/output_writers.py", line 336, in append
self.flush()
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/output_writers.py", line 371, in flush
COUNTER_IO_WRITE_BYTES, len(str_buf))(self._ctx)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 297, in __exit__
self.close()
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 291, in close
self._make_rpc_call_with_retry('Close', request, response)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 427, in _make_rpc_call_with_retry
_make_call(method, request, response)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 252, in _make_call
_raise_app_error(e)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 195, in _raise_app_error
raise FileNotOpenedError(e)
FileNotOpenedError: ApplicationError: 10
Traceback (most recent call last):
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/main.py", line 105, in main
util.run_wsgi_app(APP)
File "/python27_runtime/python27_lib/versions/1/google/appengine/ext/webapp/util.py", line 98, in run_wsgi_app
run_bare_wsgi_app(add_wsgi_middleware(application))
File "/python27_runtime/python27_lib/versions/1/google/appengine/ext/webapp/util.py", line 116, in run_bare_wsgi_app
result = application(env, _start_response)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1519, in __call__
response = self._internal_error(e)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1511, in __call__
rv = self.handle_exception(request, response, e)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1505, in __call__
rv = self.router.dispatch(request, response)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1253, in default_dispatcher
return route.handler_adapter(request, response)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 1077, in __call__
return handler.dispatch()
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 547, in dispatch
return self.handle_exception(e, self.app.debug)
File "/python27_runtime/python27_lib/versions/third_party/webapp2-2.3/webapp2.py", line 545, in dispatch
return method(*args, **kwargs)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/base_handler.py", line 65, in post
self.handle()
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/handlers.py", line 181, in handle
entity, input_reader, ctx, tstate)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/handlers.py", line 298, in process_data
output_writer.write(output, ctx)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/output_writers.py", line 693, in write
ctx.get_pool("records_pool").append(str(data))
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/output_writers.py", line 336, in append
self.flush()
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/output_writers.py", line 371, in flush
COUNTER_IO_WRITE_BYTES, len(str_buf))(self._ctx)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 297, in __exit__
self.close()
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 291, in close
self._make_rpc_call_with_retry('Close', request, response)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 427, in _make_rpc_call_with_retry
_make_call(method, request, response)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 252, in _make_call
_raise_app_error(e)
File "/base/data/home/apps/s~getaround3/dont-make-this-default-export-mr.366029363091232181/mapreduce/lib/files/file.py", line 195, in _raise_app_error
raise FileNotOpenedError(e)
FileNotOpenedError: ApplicationError: 10
答案 0 :(得分：2)
我增加了可能解决问题的分片数量。增加分片数量会减少每个片段保持文件打开的时间，这可能是我遇到问题的原因。
答案 1 :(得分：0)
保持文件打开超过30秒也会导致此错误。尝试将写入分成多个写入。
refer link for deatils https://groups.google.com/forum/#!topic/google-appengine-java/5XBVaVDKvvs