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From lars hofhansl <lhofha...@yahoo.com>
Subject Re: Confirming a Bug
Date Sun, 18 Mar 2012 21:51:32 GMT
Hi Peter,

(this is the other Lars)

Does this depend on your dataset at all? Does not it also happen for smaller value of scanner

Any chance that you can reproduce this in a unittest and file a jira?
If you do (specifically the test), I'll promise I'll look at it this week :)

-- Lars (H)

 From: Peter Wolf <opus111@gmail.com>
To: user@hbase.apache.org 
Sent: Sunday, March 18, 2012 7:13 AM
Subject: Re: Confirming a Bug
Hi Lars,

I don't think so...  My behavior is definitely tied to the amount of 
data in each Result.  There definitely seems to be some sort of 
threshold.  Changing the caching amount produces a completely repeatable 
behavior.  10,000, 5,000, and 1000 each produce different repeatable 
results, and changing the families added as produces different reliable 
results. There is no "sometimes" or "occasional", and if there was a 
Major Compaction, it wouldn't happen that often.


Note that with all my families added each result is a few 1000 bytes 
big.  Is that unusually large?


On 3/18/12 5:28 AM, Lars George wrote:
> Hi Peter,
> Could you be hitting HBASE-5121? Or even HBASE-2856?
> Lars
> On Mar 17, 2012, at 20:46, Peter Wolf<opus111@gmail.com>  wrote:
>> Hello,
>> A couple of days ago, I asked about strange behavior in my "Scan.addFamiliy reduces
results" thread.
>> I want to confirm that I did find a bug, and if so, how to submit a bug report.
>> The basic strangeness is that changing the amount of caching, changes the number
of results.  In the original thread, this was confused by the fact that adding different
families also changed the number of results.  We thought it was a filtering problem.
>> However, changing nothing but the setCaching() value changes the number of results. 
Furthermore, the result difference is a multiple of the setCaching() value.
>> Here is the pseudo code:
>>         Scan scan = new Scan(...);
>>         scan.addFamily(...);
>>         Filter filter = ...
>>         scan.setFilter(filter);
>> -->      scan.setCaching(10000);<--
>>         scanner = hTable.getScanner(scan);
>>         Iterator<Result>  it = scanner.iterator();
>>         while (it.hasNext()) {
>>             Result result = it.next();
>>             ...
>>         }
>> Thank you
>> Peter
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