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HBase >> mail # user >> HBase random read performance


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Ankit Jain 2013-04-13, 05:31
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Ted Yu 2013-04-13, 15:16
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Adrien Mogenet 2013-04-13, 16:00
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Harsh J 2013-04-13, 17:02
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Jean-Marc Spaggiari 2013-04-14, 21:58
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Anoop Sam John 2013-04-15, 10:17
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Rishabh Agrawal 2013-04-15, 10:42
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Ankit Jain 2013-04-15, 10:53
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谢良 2013-04-15, 11:41
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Ankit Jain 2013-04-15, 13:04
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Doug Meil 2013-04-15, 13:21
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Ted Yu 2013-04-15, 13:30
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Ted Yu 2013-04-15, 14:13
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Re: 答复: HBase random read performance
This is a related JIRA which should provide noticeable speed up:

HBASE-1935 Scan in parallel

Cheers

On Mon, Apr 15, 2013 at 7:13 AM, Ted Yu <[EMAIL PROTECTED]> wrote:

> I looked
> at src/main/java/org/apache/hadoop/hbase/client/HConnectionManager.java in
> 0.94
>
> In processBatchCallback(), starting line 1538,
>
>         // step 1: break up into regionserver-sized chunks and build the
> data structs
>         Map<HRegionLocation, MultiAction<R>> actionsByServer >           new HashMap<HRegionLocation, MultiAction<R>>();
>         for (int i = 0; i < workingList.size(); i++) {
>
> So we do group individual action by server.
>
> FYI
>
> On Mon, Apr 15, 2013 at 6:30 AM, Ted Yu <[EMAIL PROTECTED]> wrote:
>
>> Doug made a good point.
>>
>> Take a look at the performance gain for parallel scan (bottom chart
>> compared to top chart):
>> https://issues.apache.org/jira/secure/attachment/12578083/FDencode.png
>>
>> See
>> https://issues.apache.org/jira/browse/HBASE-8316?focusedCommentId=13628300&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13628300for explanation of the two methods.
>>
>> Cheers
>>
>> On Mon, Apr 15, 2013 at 6:21 AM, Doug Meil <[EMAIL PROTECTED]
>> > wrote:
>>
>>>
>>> Hi there, regarding this...
>>>
>>> > We are passing random 10000 row-keys as input, while HBase is taking
>>> around
>>> > 17 secs to return 10000 records.
>>>
>>>
>>> ….  Given that you are generating 10,000 random keys, your multi-get is
>>> very likely hitting all 5 nodes of your cluster.
>>>
>>>
>>> Historically, multi-Get used to first sort the requests by RS and then
>>> *serially* go the RS to process the multi-Get.  I'm not sure of the
>>> current (0.94.x) behavior if it multi-threads or not.
>>>
>>> One thing you might want to consider is confirming that client behavior,
>>> and if it's not multi-threading then perform a test that does the same RS
>>> sorting via...
>>>
>>>
>>> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html#
>>> getRegionLocation%28byte[<http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html#getRegionLocation%28byte[>
>>> ]%29
>>>
>>> …. and then spin up your own threads (one per target RS) and see what
>>> happens.
>>>
>>>
>>>
>>> On 4/15/13 9:04 AM, "Ankit Jain" <[EMAIL PROTECTED]> wrote:
>>>
>>> >Hi Liang,
>>> >
>>> >Thanks Liang for reply..
>>> >
>>> >Ans1:
>>> >I tried by using HFile block size of 32 KB and bloom filter is enabled.
>>> >The
>>> >random read performance is 10000 records in 23 secs.
>>> >
>>> >Ans2:
>>> >We are retrieving all the 10000 rows in one call.
>>> >
>>> >Ans3:
>>> >Disk detai:
>>> >Model Number:       ST2000DM001-1CH164
>>> >Serial Number:      Z1E276YF
>>> >
>>> >Please suggest some more optimization
>>> >
>>> >Thanks,
>>> >Ankit Jain
>>> >
>>> >On Mon, Apr 15, 2013 at 5:11 PM, 谢良 <[EMAIL PROTECTED]> wrote:
>>> >
>>> >> First, it's probably helpless to set block size to 4KB, please refer
>>> to
>>> >> the beginning of HFile.java:
>>> >>
>>> >>  Smaller blocks are good
>>> >>  * for random access, but require more memory to hold the block index,
>>> >>and
>>> >> may
>>> >>  * be slower to create (because we must flush the compressor stream at
>>> >>the
>>> >>  * conclusion of each data block, which leads to an FS I/O flush).
>>> >> Further, due
>>> >>  * to the internal caching in Compression codec, the smallest possible
>>> >> block
>>> >>  * size would be around 20KB-30KB.
>>> >>
>>> >> Second, is it a single-thread test client or multi-threads? we
>>> couldn't
>>> >> expect too much if the requests are one by one.
>>> >>
>>> >> Third, could you provide more info about  your DN disk numbers and IO
>>> >> utils ?
>>> >>
>>> >> Thanks,
>>> >> Liang
>>> >> ________________________________________
>>> >> 发件人: Ankit Jain [[EMAIL PROTECTED]]
>>> >> 发送时间: 2013年4月15日 18:53
>>> >> 收件人: [EMAIL PROTECTED]
>>> >> 主题: Re: HBase random read performance
>>> >>
>>> >> Hi Anoop,
>>> >>
>>> >> Thanks for reply..
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lars hofhansl 2013-04-16, 14:55
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Liu, Raymond 2013-04-16, 07:49
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Nicolas Liochon 2013-04-16, 08:22
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Jean-Marc Spaggiari 2013-04-16, 11:01
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Michel Segel 2013-04-17, 12:33
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Håvard Wahl Kongsgård 2013-04-14, 22:19
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Mohammad Tariq 2013-04-14, 22:39
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Ted Yu 2013-07-08, 12:49