Home | About | Sematext search-lucene.com search-hadoop.com
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
 Search Hadoop and all its subprojects:

Switch to Plain View
HBase >> mail # user >> Essential column family performance


+
James Taylor 2013-04-07, 06:05
+
Ted Yu 2013-04-07, 14:44
+
James Taylor 2013-04-07, 18:37
+
Ted Yu 2013-04-07, 23:03
+
Ted Yu 2013-04-07, 23:13
+
lars hofhansl 2013-04-08, 03:52
+
Ted Yu 2013-04-08, 14:49
+
Anoop John 2013-04-08, 17:10
Copy link to this message
-
Re: Essential column family performance
In the TestJoinedScanners.java, is the 40% randomly distributed or
sequential?

In our test, the % is randomly distributed. Also, our custom filter does
the same thing that SingleColumnValueFilter does.  On the client-side,
we'd execute the query in parallel, through multiple scans along the
region boundaries. Would that have a negative impact on performance for
this "essential column family" feature?

Thanks,

     James

On 04/08/2013 10:10 AM, Anoop John wrote:
> 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):
>>> Joined scanner finished in 0.47235 seconds, got 100 rows
>>>
>>> Cheers
>>>
>>> On Sun, Apr 7, 2013 at 4:03 PM, Ted Yu <[EMAIL PROTECTED]> wrote:
>>>
>>>> Looking at
>>>>
>> https://issues.apache.org/jira/secure/attachment/12564340/5416-0.94-v3.txt
>> ,
>>> I found that it didn't contain TestJoinedScanners which shows
>>>> difference in scanner performance:
>>>>
>>>>     LOG.info((slow ? "Slow" : "Joined") + " scanner finished in " +
>>>> Double.toString(timeSec)
>>>>
>>>>        + " seconds, got " + Long.toString(rows_count/2) + " rows");
>>>>
>>>> The test uses SingleColumnValueFilter:
>>>>
>>>>      SingleColumnValueFilter filter = new SingleColumnValueFilter(
>>>>
>>>>          cf_essential, col_name, CompareFilter.CompareOp.EQUAL,
>> flag_yes);
>>>> It is possible that the custom filter you were using would exhibit
>>>> different access pattern compared to SingleColumnValueFilter. e.g. does
>>>> your filter utilize hint ?
>>>> It would be easier for me and other people to reproduce the issue you
>>>> experienced if you put your scenario in some test similar to
>>>> TestJoinedScanners.
>>>>
>>>> Will take a closer look at the code Monday.
>>>>
>>>> Cheers
>>>>
>>>> On Sun, Apr 7, 2013 at 11:37 AM, James Taylor <[EMAIL PROTECTED]
>>>> wrote:
>>>>
>>>>> Yes, on 0.94.6. We have our own custom filter derived from FilterBase,
+
Ted Yu 2013-04-08, 17:42
+
Ted Yu 2013-04-08, 18:02
+
ramkrishna vasudevan 2013-04-08, 17:51
+
Sergey Shelukhin 2013-04-08, 20:34
+
Ted Yu 2013-04-08, 21:15
+
lars hofhansl 2013-04-08, 21:41
+
James Taylor 2013-04-09, 01:53
+
lars hofhansl 2013-04-09, 23:47
+
Ted Yu 2013-04-10, 00:03
+
Ted Yu 2013-04-09, 02:51
+
Jean-Marc Spaggiari 2013-04-08, 17:19
+
Ted Yu 2013-04-08, 17:23
+
Michael Segel 2013-04-08, 18:07
+
lars hofhansl 2013-04-08, 21:29
+
Lars Hofhansl 2013-04-10, 01:17
+
Ted Yu 2013-04-10, 01:21
+
Ted Yu 2013-04-10, 04:03
+
lars hofhansl 2013-04-10, 04:16
+
Anoop Sam John 2013-04-10, 05:30
+
lars hofhansl 2013-04-10, 23:02
+
Stack 2013-04-10, 23:35
+
Ted Yu 2013-04-10, 23:05
+
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