Liu Shaohui created HBASE-11541:
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Summary: Wrong result when scaning meta with startRow
Key: HBASE-11541
URL: https://issues.apache.org/jira/browse/HBASE-11541
Project: HBase
Issue Type: Bug
Reporter: Liu Shaohui
Assignee: Liu Shaohui
Priority: Minor
When we scan the meta with STARTROW optiion, wrong result may be returned.
For exmaple: if there are two tables named "a" and "b" in hbase, when we scan
the meta with startrow = 'b', the region location of table "a" will be returned
but we expect to get the region location of table "b".
{code}
> create 'a', {NAME => 'f'}
> create 'b', {NAME => 'f'}
> scan '.META.', {STARTROW => 'b', LIMIT => 1}
a,,1405655897758.f8b547476b6dc80545e6413c31396, xxxx
{code}
The reason is the wrong assumption in MetaKeyComparator
See: KeyValue.java#2011
{code}
int leftDelimiter = getDelimiter(left, loffset, llength,
HRegionInfo.DELIMITER);
int rightDelimiter = getDelimiter(right, roffset, rlength,
HRegionInfo.DELIMITER);
if (leftDelimiter < 0 && rightDelimiter >= 0) {
// Nothing between .META. and regionid. Its first key.
return -1;
} else if (rightDelimiter < 0 && leftDelimiter >= 0) {
return 1;
} else if (leftDelimiter < 0 && rightDelimiter < 0) {
return 0;
}
{code}
It's a little troublesome to fix this problem for given a start row which
contains more than two "," for meta, it's not easy to extract the startKey of
region.
eg: STARTROW => 'aaa,bbb,ccc,xxx'.
Comments and suggestions are welcomed. Thanks
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