我是流技术的初学者，尝试使用结构化流技术进行预测性维护用例，但在（csv-）DataStream上进行预测时遇到错误。
非常感谢！！
将调用以下函数，并且如果我删除了预测部分，则它不会返回任何错误-已预加载模型并且DataStreamreader也正在运行：
def process_row(row):
"""Fif and preprocess"""
list_feat_col_num = [item[0] for item in row.dtypes if item[1].startswith('int')|item[1].startswith('double')]
vec_assembler = VectorAssembler(inputCols=list_feat_col_num, outputCol="features")
row_transformed = vec_assembler.transform(row).select('machineID','datetime','failure','features')
featureIndexer = VectorIndexer(inputCol="features",outputCol="indexedFeatures",
handleInvalid ="skip",
maxCategories=10).fit(row_transformed)
print(row_transformed)
# error comes from prediction part
"""predict"""
rf = RandomForestClassificationModel.load("content/model")
pipeline_rf_pred = Pipeline(stages=[featureIndexer, rf])
row_transformed = pipeline_rf_pred.fit(row_transformed)
prediction = model_rf.transform(row_transformed)
print(prediction)
pass
> Traceback (most recent call last):
File "/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/serializers.py", line 590, in dumps
return cloudpickle.dumps(obj, 2)
File "/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/cloudpickle.py", line 863, in dumps
cp.dump(obj)
File "/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/cloudpickle.py", line 260, in dump
return Pickler.dump(self, obj)
File "/usr/lib/python3.6/pickle.py", line 409, in dump
self.save(obj)
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/usr/lib/python3.6/pickle.py", line 751, in save_tuple
save(element)
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/cloudpickle.py", line 406, in save_function
self.save_function_tuple(obj)
File "/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/cloudpickle.py", line 549, in save_function_tuple
save(state)
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/usr/lib/python3.6/pickle.py", line 821, in save_dict
self._batch_setitems(obj.items())
File "/usr/lib/python3.6/pickle.py", line 847, in _batch_setitems
save(v)
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/usr/lib/python3.6/pickle.py", line 781, in save_list
self._batch_appends(obj)
File "/usr/lib/python3.6/pickle.py", line 808, in _batch_appends
save(tmp[0])
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/cloudpickle.py", line 400, in save_function
self.save_function_tuple(obj)
File "/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/cloudpickle.py", line 549, in save_function_tuple
save(state)
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/usr/lib/python3.6/pickle.py", line 821, in save_dict
self._batch_setitems(obj.items())
File "/usr/lib/python3.6/pickle.py", line 847, in _batch_setitems
save(v)
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/usr/lib/python3.6/pickle.py", line 821, in save_dict
self._batch_setitems(obj.items())
File "/usr/lib/python3.6/pickle.py", line 847, in _batch_setitems
save(v)
File "/usr/lib/python3.6/pickle.py", line 521, in save
self.save_reduce(obj=obj, *rv)
File "/usr/lib/python3.6/pickle.py", line 634, in save_reduce
save(state)
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/usr/lib/python3.6/pickle.py", line 821, in save_dict
self._batch_setitems(obj.items())
File "/usr/lib/python3.6/pickle.py", line 847, in _batch_setitems
save(v)
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/usr/lib/python3.6/pickle.py", line 781, in save_list
self._batch_appends(obj)
File "/usr/lib/python3.6/pickle.py", line 805, in _batch_appends
save(x)
File "/usr/lib/python3.6/pickle.py", line 521, in save
self.save_reduce(obj=obj, *rv)
File "/usr/lib/python3.6/pickle.py", line 634, in save_reduce
save(state)
File "/usr/lib/python3.6/pickle.py", line 476, in save
f(self, obj) # Call unbound method with explicit self
File "/usr/lib/python3.6/pickle.py", line 821, in save_dict
self._batch_setitems(obj.items())
File "/usr/lib/python3.6/pickle.py", line 847, in _batch_setitems
save(v)
File "/usr/lib/python3.6/pickle.py", line 496, in save
rv = reduce(self.proto)
File "/content/spark-2.4.3-bin-hadoop2.7/python/lib/py4j-0.10.7-src.zip/py4j/java_gateway.py", line 1257, in __call__
answer, self.gateway_client, self.target_id, self.name)
File "/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/sql/utils.py", line 63, in deco
return f(*a, **kw)
File "/content/spark-2.4.3-bin-hadoop2.7/python/lib/py4j-0.10.7-src.zip/py4j/protocol.py", line 332, in get_return_value
format(target_id, ".", name, value))
py4j.protocol.Py4JError: An error occurred while calling o281.__getstate__. Trace:
py4j.Py4JException: Method __getstate__([]) does not exist
at py4j.reflection.ReflectionEngine.getMethod(ReflectionEngine.java:318)
at py4j.reflection.ReflectionEngine.getMethod(ReflectionEngine.java:326)
at py4j.Gateway.invoke(Gateway.java:274)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:238)
at java.lang.Thread.run(Thread.java:748)
---------------------------------------------------------------------------
Py4JError Traceback (most recent call last)
/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/serializers.py in dumps(self, obj)
589 try:
--> 590 return cloudpickle.dumps(obj, 2)
591 except pickle.PickleError:
44 frames
Py4JError: An error occurred while calling o281.__getstate__. Trace:
py4j.Py4JException: Method __getstate__([]) does not exist
at py4j.reflection.ReflectionEngine.getMethod(ReflectionEngine.java:318)
at py4j.reflection.ReflectionEngine.getMethod(ReflectionEngine.java:326)
at py4j.Gateway.invoke(Gateway.java:274)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:238)
at java.lang.Thread.run(Thread.java:748)
During handling of the above exception, another exception occurred:
PicklingError Traceback (most recent call last)
/content/spark-2.4.3-bin-hadoop2.7/python/pyspark/serializers.py in dumps(self, obj)
598 msg = "Could not serialize object: %s: %s" % (e.__class__.__name__, emsg)
599 cloudpickle.print_exec(sys.stderr)
--> 600 raise pickle.PicklingError(msg)
601
602
PicklingError: Could not serialize object: Py4JError: An error occurred while calling o281.__getstate__. Trace:
py4j.Py4JException: Method __getstate__([]) does not exist
at py4j.reflection.ReflectionEngine.getMethod(ReflectionEngine.java:318)
at py4j.reflection.ReflectionEngine.getMethod(ReflectionEngine.java:326)
at py4j.Gateway.invoke(Gateway.java:274)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:238)
at java.lang.Thread.run(Thread.java:748)