HBaseCoprocessor analysis and programming practices

1. WhyHBaseCoprocessor HBase, as a column Family database, is most often criticized. features include: It is difficult to easily create secondary indexes and perform operations such as sum, count, and sort. For example, in the old version (0.92) Hbase, to count the total number of rows in a data table, you need to use the Counter method to execute a MapReduceJob. Although HBa

1. Why HBase Coprocessor HBase, as a column Family database, is most often criticized. features include: It is difficult to easily create secondary indexes and perform operations such as sum, count, and sort. For example, in the old version (0.92) Hbase, to count the total number of rows in a data table, you need to use the Counter method to execute a MapReduce Job. Although HBa

1. Cause (Why HBase Coprocessor)

HBase, as a column Family database, is most often criticized for the following features: it is difficult to easily create a "secondary index" and to perform operations such as sum, count, and sort. For example, in the earlier version (<0.92) Hbase, the website space, the total number of rows in the statistical data table, and the website space must use the Counter method to execute a MapReduce Job. Although HBase integrates MapReduce in the data storage layer, it can be effectively used for Distributed Computing of data tables. However, in many cases, if you directly place the computing process on the server side during simple addition or aggregation computing, the communication overhead can be reduced to achieve good performance improvement. As a result, HBase introduced coprocessors after 0.92 to implement some exciting new features: the ability to easily create secondary indexes, complex filters (predicate push-down), and access control.

2. Source of Inspration)

The HBase coprocessor was inspired by Jeff Dean's speech (P66-67) in the year 09 ). Based on the speech, it implements coprocessor similar to bigtable, including the following features:

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