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https://issues.apache.org/jira/browse/HBASE-15325?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15196799#comment-15196799
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Anoop Sam John edited comment on HBASE-15325 at 3/16/16 5:42 AM:
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Seems u have not done the one optimization way while batching is used (The one
u suggested) Dont want it? Its ok any way.
{code}
if (this.lastResult.isPartial() || scan.getBatch() > 0 ) {
508 updateLastCellLoadedToCache(this.lastResult);
509 }
{code}
My suggestion was add an else case and update the lastCellLoadedToCache to be
null. Add a clear comment in the variable that this is the last cell from a
not full Row which is added to cache (And so returned/ may return to user) May
be some better name also we can get? May that will be too long name.
So this check can be changed
{code}
if (this.lastResult != null && (this.lastResult.isPartial() || scan.getBatch()
> 0 )) {
496 rs = filterLoadedCell(rs);
{code}
To
{code}
if(this.lastCellLoadedToCache != null) {
rs = filterLoadedCell(rs);
{code}
{code}
List<Cell> list = new ArrayList<>(result.rawCells().length - index);
858 for (; index < result.rawCells().length; index++) {
859 list.add(result.rawCells()[index]);
860 }
{code}
can u change it to array and add cells to that and use Result.create API which
takes array? Small optimization. Still worth it as no extra lines or so.
was (Author: anoop.hbase):
Seems u have not done the one optimization way while batching is used (The one
u suggested) Dont want it? Its ok any way.
{code}
if (this.lastResult.isPartial() || scan.getBatch() > 0 ) {
508 updateLastCellLoadedToCache(this.lastResult);
509 }
{code}
My suggestion was add an else case and update the lastCellLoadedToCache to be
null. Add a clear comment in the variable that this is the last cell from a
not full Row which is added to cache (And so returned/ may return to user) May
be some better name also we can get? May that will be too long name.
So this check can be changed
{code}
if (this.lastResult != null && (this.lastResult.isPartial() || scan.getBatch()
> 0 )) {
496 rs = filterLoadedCell(rs);
{code}
To
if(this.lastCellLoadedToCache != null) {
rs = filterLoadedCell(rs);
{code}
{code}
List<Cell> list = new ArrayList<>(result.rawCells().length - index);
858 for (; index < result.rawCells().length; index++) {
859 list.add(result.rawCells()[index]);
860 }
{code}
can u change it to array and add cells to that and use Result.create API which
takes array? Small optimization. Still worth it as no extra lines or so.
> ResultScanner allowing partial result will miss the rest of the row if the
> region is moved between two rpc requests
> -------------------------------------------------------------------------------------------------------------------
>
> Key: HBASE-15325
> URL: https://issues.apache.org/jira/browse/HBASE-15325
> Project: HBase
> Issue Type: Bug
> Components: dataloss, Scanners
> Affects Versions: 1.2.0, 1.1.3
> Reporter: Phil Yang
> Assignee: Phil Yang
> Priority: Critical
> Fix For: 2.0.0, 1.3.0, 1.2.1, 1.1.4, 1.4.0
>
> Attachments: 15325-test.txt, HBASE-15325-v1.txt,
> HBASE-15325-v10.patch, HBASE-15325-v2.txt, HBASE-15325-v3.txt,
> HBASE-15325-v5.txt, HBASE-15325-v6.1.txt, HBASE-15325-v6.2.txt,
> HBASE-15325-v6.3.txt, HBASE-15325-v6.4.txt, HBASE-15325-v6.5.txt,
> HBASE-15325-v6.txt, HBASE-15325-v7.patch, HBASE-15325-v8.patch,
> HBASE-15325-v9.patch
>
>
> HBASE-11544 allow scan rpc return partial of a row to reduce memory usage for
> one rpc request. And client can setAllowPartial or setBatch to get several
> cells in a row instead of the whole row.
> However, the status of the scanner is saved on server and we need this to get
> the next part if there is a partial result before. If we move the region to
> another RS, client will get a NotServingRegionException and open a new
> scanner to the new RS which will be regarded as a new scan from the end of
> this row. So the rest cells of the row of last result will be missing.
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