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Anoop Sam John edited comment on HBASE-15180 at 2/16/16 7:50 AM: ----------------------------------------------------------------- Ya the test code change looks fine. I will fix that in the next version of patch. was (Author: anoop.hbase): Ya the test code change looks fine. > Reduce garbage created while reading Cells from Codec Decoder > ------------------------------------------------------------- > > Key: HBASE-15180 > URL: https://issues.apache.org/jira/browse/HBASE-15180 > Project: HBase > Issue Type: Sub-task > Components: regionserver > Affects Versions: 0.98.0 > Reporter: Anoop Sam John > Assignee: Anoop Sam John > Fix For: 2.0.0, 1.3.0, 1.2.1 > > Attachments: HBASE-15180.patch, HBASE-15180_V2.patch, > HBASE-15180_V4.patch > > > In KeyValueDecoder#parseCell (Default Codec decoder) we use > KeyValueUtil#iscreate to read cells from the InputStream. Here we 1st create > a byte[] of length 4 and read the cell length and then an array of Cell's > length and read in cell bytes into it and create a KV. > Actually in server we read the reqs into a byte[] and CellScanner is created > on top of a ByteArrayInputStream on top of this. By default in write path, we > have MSLAB usage ON. So while adding Cells to memstore, we will copy the Cell > bytes to MSLAB memory chunks (default 2 MB size) and recreate Cells over that > bytes. So there is no issue if we create Cells over the RPC read byte[] > directly here in Decoder. No need for 2 byte[] creation and copy for every > Cell in request. > My plan is to make a Cell aware ByteArrayInputStream which can read Cells > directly from it. > Same Codec path is used in client side also. There better we can avoid this > direct Cell create and continue to do the copy to smaller byte[]s path. Plan > to introduce some thing like a CodecContext associated with every Codec > instance which can say the server/client context. -- This message was sent by Atlassian JIRA (v6.3.4#6332)