Fisher–yates Shuffle basic idea (Knuth Shuffle):
To shuffle A of n elements (indices 0..n-1):For i-n−1 downto 1 DoJ←random integer with 0≤j≤iExchange A[j] and A[i]
JDK source code is as follows:
Copy Code code as follows:
/**
* Moves
Shuffle describes the process of data from the map task output to the reduce task input.Personal Understanding:The results of map execution are saved as a local file:As long as map execution is complete, the in-memory map data will be saved to the
Shuffle () defines and uses the shuffle () function to rearrange the elements in the array in random order. Returns TRUE if successful, otherwise FALSE is returned. Note: This function assigns the new key name to the cells in the array. This will
Shuffle () defines and uses the shuffle () function to rearrange the elements in the array in random order. Returns TRUE if successful, otherwise FALSE is returned. Note: This function assigns the new key name to the cells in the array. This will
Mapreduce: Describes the shuffle process]
Blog type:
Mapreduce
Mapreduceiteye multi-thread hadoop Data Structure
The shuffle process is the core of mapreduce, also known as a miracle. To understand mapreduce, shuffle must be understood. I have
The shuffle process is the core of mapreduce, also known as a miracle. To understand mapreduce, shuffle must be understood. I have read a lot of related materials, but every time I read them, it is difficult to clarify the general logic, but it is
The shuffle process is the core of MapReduce, also known as the place where miracles occur. To understand mapreduce,shuffle, you have to understand. I have seen a lot of relevant information, but every time I read the foggy around, it is difficult
The shuffle process is the core of mapreduce, also known as a miracle. To understand mapreduce, shuffle must be understood. I have read a lot of related materials, but every time I read them, it is difficult to clarify the general logic, but it is
The shuffle process is the core of mapreduce, also known as a miracle. To understand mapreduce, shuffle must be understood. I have read a lot of related materials, but every time I read them, it is difficult to clarify the general logic, but it
The shuffle process is the core of mapreduce, also known as a miracle. To understand mapreduce, shuffle must be understood. I have read a lot of related materials, but every time I read them, it is difficult to clarify the general logic, but it is
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