Lineage(血统)
时间: 2024-05-19 14:16:06 浏览: 19
Lineage refers to the descent of a person or group of people from a common ancestor or ancestry. It is the tracing of a family's or group's genealogy, heritage, and ancestral background. Lineage often includes the family's history, traditions, customs, and cultural practices that have been passed down from generation to generation. It is a term commonly used in genealogy and family history research to understand one's roots and heritage.
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Spark Lineage
As an AI language model, I don't have personal biases or experience. However, I can provide you with information on what Spark Lineage is.
Spark Lineage refers to the lineage tracking mechanism in Apache Spark, which keeps track of the data flow in a Spark application. It helps users to understand how the data is transformed and where it came from. Lineage tracking is important for debugging, optimization, and auditing purposes.
Spark Lineage creates a Directed Acyclic Graph (DAG) of the data transformations, which can be visualized using tools like Databricks or Apache Zeppelin. The DAG shows the dependencies between the input data and the output data of each transformation.
Lineage tracking in Spark is automatic and transparent to the user. It is enabled by default and can be accessed through the Spark UI or the Spark History Server. Users can also programmatically access the lineage information using the Spark API.
In summary, Spark Lineage is a mechanism that tracks the data flow in a Spark application to help users understand the transformation process, optimize performance, and ensure data integrity.
Spark 中lineage
在Spark中,Lineage(血统)是指每个RDD(弹性分布式数据集)的来源和转换历史记录。RDD是Spark中的核心数据结构,其实际内容被分成一系列分区,这些分区可以在集群中的不同节点上并行处理。每个RDD都可以从其他RDD转换而来,这些转换操作可以包括映射、过滤、聚合等。而RDD的Lineage则记录了这些转换过程,使得Spark可以在出现故障时自动恢复丢失的数据。
具体来说,当一个RDD丢失时,Spark会根据该RDD的Lineage自动重建它。因为每个RDD都知道它是如何从父RDD转换而来的,所以Spark可以逐级向上查找丢失的数据,并重新计算丢失的分区。这种机制使得Spark具有很高的容错性和可靠性,即使在出现故障时也可以保证计算的正确性和完整性。