The eggs inside the shells are likened to Data nodes

[shaownhasan]

Simply put, HDFS is like a salted egg. There is a shell, there is an egg part. Well, the shell is like a Name node. You can tell it is a salted egg from the color of the shell, the salted egg production stamp (if there is one), and the expiration stamp too. However, the shell is not something you can eat.

When you buy salted eggs, you definitely want to eat the eggs, not the shells. Well, You can australia email list eat the salted eggs, feel the texture, taste, etc. Just like Data nodes that record real files.

However, Name node and Data node are equally important. Like salted eggs. Have you ever bought salted eggs but there were no shells? Or bought salted eggs but there were no eggs? Like currency that cannot be separated from the principal.

Yarn
What is this yarn anyway? Simply put, Yarn is what regulates the flow of data processing in HDFS. It is impossible for incoming and outgoing files not to be regulated. Traffic has traffic lights, why not big data? Hehehe.

Just like HDFS, Yarn is also divided into 2 parts. The first part is called Resources Manager . Well, this function is similar to traffic light. If there is a green light (request accepted), new data / files can be recorded (write & read). Likewise, if there is a red light (request rejected), then the data / files cannot be recorded (write & read).