rojeck

Nov 26

Principles of composition/aggregation reuse

The Composite/Aggregate Reuse Principle (CARP) is generally called the Composite Reuse Principle (CRP), which is defined as: try to use composite/aggregate instead of inheriting to achieve the purpose of reuse. The principle of composition/aggregation reuse is to use some existing objects in a new object to make it a part of the new object; the new object achieves the purpose of reusing existing functions by delegating to these objects held internally. Instead of getting existing functions th...

rojeck

Dec 19

1. Salt

The application of Salting in HBase is to assign a random character to each rowkey prefix, so that the data is scattered in multiple different regions to achieve a balanced load. If the table region in HBase is distinguished according to the prefix of each letter, let's compare the changes before and after adding salt to the rowkey. First, we give a set of rowkeys before salt: rk001 rk002 rk003 According to the partition, the above rowkey is in the same region. Below we add salt to the above ...

rojeck

Nov 11

Significance of the Single Responsibility Principle

The single responsibility principle tells us: a class cannot do too many things. In a software system, the more responsibilities a class (a module, or a method) assumes, the lower the possibility of it being reused. A very typical example is the universal class. In fact, we can tell the truth: any conventional MVC project, in extreme cases, can use one class (or even one method) to complete all functions. But doing so will cause serious coupling and even affect the whole body. A class underta...