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https://issues.apache.org/jira/browse/HBASE-15236?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Appy updated HBASE-15236:
-------------------------
Description:
If there are two bulkloaded hfiles in a region with same seqID and duplicate
keys*, get and scan may return different values for a key.
More details:
- one of the rows had 200k+ columns. say row is 'r', column family is 'cf' and
column qualifiers are 1 to 1000.
- hfiles were split somewhere along that row, but there were a range of columns
in both hfiles. For eg, something like - hfile1: ["", r:cf:70) and hfile2:
[r:cf:40, ....).
- Between columns 40 to 70, some (not all) columns were in both the files with
different values. Whereas other were only in one of the files.
In such a case, depending on file size (because we take it into account when
sorting hfiles internally), we may get different values for the same cell (say
"r", "cf:50") depending on what we call: get "r" "cf:50" or get "r" "cf:".
I have been able to replicate this issue, will post the instructions shortly.
---
\* not sure how this would happen. These files are small ~50M, nor could i find
any setting for max file size that could lead to splits. Need to investigate
more.
was:
If there are two bulkloaded hfiles in a region with same seqID and duplicate
keys*, get and scan may return different values for a key.
More details:
- one of the rows had 200k+ columns. say row is 'r', column family is 'cf' and
column qualifiers are 1 to 1000.
- hfiles were split somewhere along that row, but there were a range of columns
in both hfiles. For eg, something like - hfile1: ["", r:cf:70) and hfile2:
[r:cf:40, ....).
- Between columns 40 to 70, some (not all) columns were in both the files with
different values. Whereas other were only in one of the files.
In such a case, depending on file size (because we take it into account when
sorting hfiles internally), we may get different values for the same cell (say
"r", "cf:50") depending on what we call: get "r" "cf:50" or get "r" "cf:".
I have been able to replicate this issue, will post the instructions shortly.
* not sure how this would happen. These files are small ~50M, nor could i find
any setting for max file size that could lead to splits. Need to investigate
more.
> Inconsistent cell reads over multiple bulk-loaded HFiles
> --------------------------------------------------------
>
> Key: HBASE-15236
> URL: https://issues.apache.org/jira/browse/HBASE-15236
> Project: HBase
> Issue Type: Bug
> Reporter: Appy
> Assignee: Appy
>
> If there are two bulkloaded hfiles in a region with same seqID and duplicate
> keys*, get and scan may return different values for a key.
> More details:
> - one of the rows had 200k+ columns. say row is 'r', column family is 'cf'
> and column qualifiers are 1 to 1000.
> - hfiles were split somewhere along that row, but there were a range of
> columns in both hfiles. For eg, something like - hfile1: ["", r:cf:70) and
> hfile2: [r:cf:40, ....).
> - Between columns 40 to 70, some (not all) columns were in both the files
> with different values. Whereas other were only in one of the files.
> In such a case, depending on file size (because we take it into account when
> sorting hfiles internally), we may get different values for the same cell
> (say "r", "cf:50") depending on what we call: get "r" "cf:50" or get "r"
> "cf:".
> I have been able to replicate this issue, will post the instructions shortly.
> ---
> \* not sure how this would happen. These files are small ~50M, nor could i
> find any setting for max file size that could lead to splits. Need to
> investigate more.
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