Star heat analysis hadoop:
https://www.cnblogs.com/zimo-jing/p/9028026.html
SSH is Secure Shell , the traditional network service program.
Data structure
A computer store, organize data the way. Data structure refers to the presence of one or more specific mutual relationship between data elements set. Typically, the data structure may be carefully selected to bring higher operational or storage efficiency . Data structures are often associated with efficient retrieval algorithms and indexing relevant technology.