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HBase >> mail # user >> Essential column family performance


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James Taylor 2013-04-07, 06:05
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Ted Yu 2013-04-07, 14:44
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James Taylor 2013-04-07, 18:37
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Ted Yu 2013-04-07, 23:03
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Ted Yu 2013-04-07, 23:13
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lars hofhansl 2013-04-08, 03:52
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Ted Yu 2013-04-08, 14:49
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Anoop John 2013-04-08, 17:10
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James Taylor 2013-04-08, 17:38
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Ted Yu 2013-04-08, 17:42
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Ted Yu 2013-04-08, 18:02
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ramkrishna vasudevan 2013-04-08, 17:51
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Sergey Shelukhin 2013-04-08, 20:34
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Ted Yu 2013-04-08, 21:15
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lars hofhansl 2013-04-08, 21:41
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James Taylor 2013-04-09, 01:53
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lars hofhansl 2013-04-09, 23:47
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Ted Yu 2013-04-10, 00:03
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Ted Yu 2013-04-09, 02:51
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Jean-Marc Spaggiari 2013-04-08, 17:19
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Ted Yu 2013-04-08, 17:23
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Re: Essential column family performance

I think that JM brings up a good point.
Keep in mind that RLL in HBase is not the same when you think of Row Level Locking in transactional systems.
Depending on the use case... you can keep things in separate tables and not worry about the issues w CF's.

So when you think about your design... separate tables may be a valid design.

IMHO I think more thought is needed before using CFs.

The Essential column family sounds like its more beneficial for edge cases and not so much for the primary use case.
Again, IMHO if you're using it for your primary use case, then I think you should rethink your schema design.

To Ted's point, by keeping like data within CFs, it makes it easier when processing data within a M/R framework since your scanner will work against the CFs in the table.

Yet, I have to ask why you would filter on one CF when pulling data from a second? Why not duplicate the data and store in both?  Again, this is highly dependent on the use case.

Just saying...
On Apr 8, 2013, at 12:23 PM, Ted Yu <[EMAIL PROTECTED]> wrote:

> Currently atomicity support in HBase is for single table, single region.
>
> If user chooses separate tables, it might be harder to implement the
> business logic.
>
> On Mon, Apr 8, 2013 at 10:19 AM, Jean-Marc Spaggiari <
> [EMAIL PROTECTED]> wrote:
>
>> Something I'm not getting, why not using separate tables instead of
>> CFs for a single table? Simply name your table tablename_cfname then
>> you get ride of the CF# limitation?
>>
>> Or is there big pros to have CFs?
>>
>> JM
>>
>> 2013/4/8 Anoop John <[EMAIL PROTECTED]>:
>>> Agree here. The effectiveness depends on what % of data satisfies the
>>> condition, how it is distributed across HFile blocks. We will get
>>> performance gain when the we will be able to skip some HFile blocks (from
>>> non essential CFs). Can test with different HFile block size (lower
>> value)?
>>>
>>> -Anoop-
>>>
>>>
>>> On Mon, Apr 8, 2013 at 8:19 PM, Ted Yu <[EMAIL PROTECTED]> wrote:
>>>
>>>> I made the following change in TestJoinedScanners.java:
>>>>
>>>> -      int flag_percent = 1;
>>>> +      int flag_percent = 40;
>>>>
>>>> The test took longer but still favors joined scanner.
>>>> I got some new results:
>>>>
>>>> 2013-04-08 07:46:06,959 INFO  [main]
>> regionserver.TestJoinedScanners(157):
>>>> Slow scanner finished in 7.424388 seconds, got 2050 rows
>>>> ...
>>>> 2013-04-08 07:46:12,010 INFO  [main]
>> regionserver.TestJoinedScanners(157):
>>>> Joined scanner finished in 5.05063 seconds, got 2050 rows
>>>>
>>>> 2013-04-08 07:46:18,358 INFO  [main]
>> regionserver.TestJoinedScanners(157):
>>>> Slow scanner finished in 6.348517 seconds, got 2050 rows
>>>> ...
>>>> 2013-04-08 07:46:22,946 INFO  [main]
>> regionserver.TestJoinedScanners(157):
>>>> Joined scanner finished in 4.587545 seconds, got 2050 rows
>>>>
>>>> Looks like effectiveness of joined scanner is affected by distribution
>> of
>>>> data.
>>>>
>>>> Cheers
>>>>
>>>> On Sun, Apr 7, 2013 at 8:52 PM, lars hofhansl <[EMAIL PROTECTED]> wrote:
>>>>
>>>>> Looking at the joined scanner test code, it sets it up such that 1% of
>>>> the
>>>>> rows match, which would somewhat be in line with James' results.
>>>>>
>>>>> In my own testing a while ago I found a 100% improvement with 0%
>> match.
>>>>>
>>>>>
>>>>> -- Lars
>>>>>
>>>>>
>>>>>
>>>>> ________________________________
>>>>> From: Ted Yu <[EMAIL PROTECTED]>
>>>>> To: [EMAIL PROTECTED]
>>>>> Sent: Sunday, April 7, 2013 4:13 PM
>>>>> Subject: Re: Essential column family performance
>>>>>
>>>>> I have attached 5416-TestJoinedScanners-0.94.txt to HBASE-5416 for
>> your
>>>>> reference.
>>>>>
>>>>> On my MacBook, I got the following results from the test:
>>>>>
>>>>> 2013-04-07 16:08:17,474 INFO  [main]
>>>> regionserver.TestJoinedScanners(157):
>>>>> Slow scanner finished in 7.973822 seconds, got 100 rows
>>>>> ...
>>>>> 2013-04-07 16:08:17,946 INFO  [main]
>>>> regionserver.TestJoinedScanners(157):
>>
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lars hofhansl 2013-04-08, 21:29
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Lars Hofhansl 2013-04-10, 01:17
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Ted Yu 2013-04-10, 01:21
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Ted Yu 2013-04-10, 04:03
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lars hofhansl 2013-04-10, 04:16
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Anoop Sam John 2013-04-10, 05:30
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lars hofhansl 2013-04-10, 23:02
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Stack 2013-04-10, 23:35
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Ted Yu 2013-04-10, 23:05
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Lars H 2013-04-10, 01:05
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB