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stack commented on HBASE-16278: ------------------------------- Makes sense [~Apache9] > Use ConcurrentHashMap instead of ConcurrentSkipListMap if possible > ------------------------------------------------------------------ > > Key: HBASE-16278 > URL: https://issues.apache.org/jira/browse/HBASE-16278 > Project: HBase > Issue Type: Improvement > Reporter: Duo Zhang > > SSD and 10G network make our system CPU bound again, so the speed of memory > operation only code becomes more and more important. > In HBase, if want to use byte[] as a map key, then we will always use CSLM > even if we do not need the map to be ordered. I know that this could save one > object allocation since we can not use byte[] directly as CHM's key. But we > all know that CHM is faster than CSLM, so I wonder if it worth to use CSLM > instead of CHM only because one extra object allocation. > Then I wrote a simple jmh micro benchmark to test the performance of CHM and > CSLM. The code could be found here > https://github.com/Apache9/microbench > It turns out that CHM is still much faster than CSLM with one extra object > allocation. > So I think we should always use CHM if we do not need the keys to be sorted. -- This message was sent by Atlassian JIRA (v6.3.4#6332)