hbase-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Ryan Rawson" <ryano...@gmail.com>
Subject Re: Review Request: delete followed by a put with the same timestamp
Date Fri, 26 Nov 2010 22:54:45 GMT

-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://review.cloudera.org/r/1252/#review1993
-----------------------------------------------------------



trunk/src/main/java/org/apache/hadoop/hbase/KeyValue.java
<http://review.cloudera.org/r/1252/#comment6297>

    what are all the consequences for not sorting by type when using KVComparator?  Does this
mean we might create HFiles that not sorted properly, because the HFile comparator uses the
KeyComparator directly with ignoreType = false. 
    
    While in memstore we can rely on memstoreTS to roughly order by insertion time, and the
Put/Delete should probably work in that situation, you are talking about modifiying a pretty
core and important concept in how we sort things.
    
    There are other ways to reconcile bugs like this, one of them is to extend the memstoreTS
concept into the HFile and use that to reconcile during reads.  There is another JIRA where
I proposed this.  
    
    If we are talking about 0.92 and beyond I'd prefer building a solid base rather than dangerous
hacks like this.  Our unit tests are not extremely extensive, so while they might pass, that
doesnt guarantee lack of bad behaviour later on.
    


- Ryan


On 2010-11-26 07:47:02, Pranav Khaitan wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://review.cloudera.org/r/1252/
> -----------------------------------------------------------
> 
> (Updated 2010-11-26 07:47:02)
> 
> 
> Review request for hbase, Jonathan Gray and Kannan Muthukkaruppan.
> 
> 
> Summary
> -------
> 
> This is a design change suggested in HBASE-3276 so adequate thought should be given before
proceeding. 
> 
> The main code change is just one line which is to ignore key type while doing KV comparisons.
When the key type is ignored, then all the keys for the same timestamp are sorted according
the order in which they were interested. It is still ensured that the delete family and delete
column will be at the top because they have the default column name and default timestamp.
> 
> 
> This addresses bug HBASE-3276.
>     http://issues.apache.org/jira/browse/HBASE-3276
> 
> 
> Diffs
> -----
> 
>   trunk/src/main/java/org/apache/hadoop/hbase/KeyValue.java 1039233 
>   trunk/src/test/java/org/apache/hadoop/hbase/regionserver/KeyValueScanFixture.java 1039233

>   trunk/src/test/java/org/apache/hadoop/hbase/regionserver/TestStoreScanner.java 1039233

> 
> Diff: http://review.cloudera.org/r/1252/diff
> 
> 
> Testing
> -------
> 
> Test cases added. Since there is a change in semantics, some previous tests were failing
because of this change. Those tests have been modified to test the newer behavior.
> 
> 
> Thanks,
> 
> Pranav
> 
>


Mime
View raw message