Spark Streaming - 可以对数据流使用离线模型(Spark Streaming - Can an offline model be used against a data stream)

 在这个链接--LINK中 ，提到已经离线构建的机器学习模型可以用于对流数据进行测试。 
 
 摘自Apache Spark Streaming MLlib链接： 
 
 “ 你也可以轻松使用MLlib提供的机器学习算法。首先，有流媒体机器学习算法（例如Streaming Linear Regression，Streaming KMeans等），它们可以同时学习流数据以及应用模型流媒体数据。 除此之外，对于更大类的机器学习算法，您可以离线学习学习模型（即使用历史数据），然后在线应用流数据模型。有关详细信息，请参阅MLlib指南。 
 
 
 
 这是否意味着可以使用像Spark中构建的Random Forest模型这样的复杂学习模型来测试Spark Streaming程序中的流数据？ 它是否像引用已构建的“模型”一样简单，并在Spark Streaming程序中调用“predictOnValues（）”？ 
 
 
 在这种情况下，现有的火花流机器学习算法（AND）之间的主要区别是这种方法是流式算法将随着时间的推移而演变，而离线（对抗）在线流式方法仍然会使用它的见解早些时候学过没有任何在线学习的可能性？ 
 
 
 我做对了吗？ 如果我对上述两点的理解是正确的，请告诉我。 

In this link - LINK, it is mentioned that a machine learning model which has been constructed offline can be used against streaming data for testing.
 
Excerpt from the Apache Spark Streaming MLlib link:
 
" You can also easily use machine learning algorithms provided by MLlib. First of all, there are streaming machine learning algorithms (e.g. Streaming Linear Regression, Streaming KMeans, etc.) which can simultaneously learn from the streaming data as well as apply the model on the streaming data. Beyond these, for a much larger class of machine learning algorithms, you can learn a learning model offline (i.e. using historical data) and then apply the model online on streaming data. See the MLlib guide for more details. "
 
 
 
Does this mean that one can use a complex learning model like Random Forest model built in Spark for testing against streaming data in Spark Streaming program? Is it as simple as referring to the "Model" which has been built and calling "predictOnValues()" over it in Spark Streaming program?
 
 
In this case, would the main difference between the existing spark streaming machine learning algorithms (AND) this approach be the fact that the streaming algorithms will evolve over time and the offline(against)online stream approach would still be using the insights from what it had learnt earlier without any possibility of online learning?
 
 
Am I getting this right? Please let me know if my understanding for both the points mentioned above is correct.

原文：https://stackoverflow.com/questions/40188693