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ramkrishna.s.vasudevan commented on HBASE-15493: ------------------------------------------------ I have been trying to make this more accurate atleast in the server side. In my case with >10 columns per cell the arraylist expansion was creating lot of garbage. But not sure if 2 is going to really help there. I know you are trying to take a middle man approach here but still. But getting the most exact estimate is much more complex in these cases. > Default ArrayList size may not be optimal for Mutation > ------------------------------------------------------ > > Key: HBASE-15493 > URL: https://issues.apache.org/jira/browse/HBASE-15493 > Project: HBase > Issue Type: Improvement > Components: Client, regionserver > Affects Versions: 2.0.0 > Reporter: Vladimir Rodionov > Assignee: Vladimir Rodionov > Fix For: 2.0.0 > > Attachments: HBASE-15493-v1.patch > > > {code} > List<Cell> getCellList(byte[] family) { > List<Cell> list = this.familyMap.get(family); > if (list == null) { > list = new ArrayList<Cell>(); > } > return list; > } > {code} > Creates list of size 10, this is up to 80 bytes per column family in mutation > object. > Suggested: > {code} > List<Cell> getCellList(byte[] family) { > List<Cell> list = this.familyMap.get(family); > if (list == null) { > list = new ArrayList<Cell>(CELL_LIST_INITIAL_CAPACITY); > } > return list; > } > {code} > CELL_LIST_INITIAL_CAPACITY = 2 in the patch, this is debatable. For mutation > where every CF has 1 cell, this gives decent reduction in memory allocation > rate in both client and server during write workload. ~2%, not a big number, > but as I said, already, memory optimization will include many small steps. -- This message was sent by Atlassian JIRA (v6.3.4#6332)