[
https://issues.apache.org/jira/browse/HBASE-15180?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15148960#comment-15148960
]
stack commented on HBASE-15180:
-------------------------------
bq. I think a better question would be why the test coverage in hbase-common
is not sufficient to capture the behavior expected by the hbase-server module.
This sounds good along w/ the general theme that modules should be
self-contained (yeah, we need to break up hbase-server, move out mapreduce,
etc.)
Can we have a better data member name than remainAwareIS? Is this flag saying
we can rely on available() giving a good answer?
Why bother with this check? Just try reading? If EOF, it'll throw an EOFE
anyways? Otherwise, if some other issue, we'll want to see that exception
rather than the EOFE we create here:
66 if(this.available()<Bytes.SIZEOF_INT){
67 throw new EOFException();
68 }
In StreamUtils, can we not read the int in one go rather than a byte-at-a-time?
Thanks.
> 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)
