Apache: Big Data North America 2017

W-TinyLFU records the frequency in a counting sketch, ages periodically by halving the counters, and orders entries by SLRU. An entry is discarded by comparing the frequency of the new arrival (candidate) to the SLRU's victim, and keeping the one with the highest frequency. This allows the operations to be performed in O(1) time and, though the use of a compact sketch, a much larger history is retained beyond the current working set. In a variety of real world traces the policy had near optimal hit rates.

Backup / Restore is standard feature for RDBMS. HBase adds support for Backup / Restore through a series of phases: HBASE-7912 (phase 1), HBASE-14123 (phase 2). Technical approach for implementing backup / restore would be covered along with typical command line usages.