Alluxio workers are responsible for managing local resources, and they store data as blocks. Users can allocate different storage tiers as the resources for Alluxio workers, including MEM/SSD/HDD, which are further composed of directories.
How does an Alluxio worker decide which directory to put a block in when a user reads or writes data through Alluxio? In this article, we analyze the policies of block allocation from the source code.