Re: Hbase Question

[Yung-An He]

Hi,

No matter how many versions of HBase class in your jar, the classloader
will choose the first one on the classpath.
Perhaps you could consider OSGi (A kind of module system).

2017-11-17 18:57 GMT+08:00 apple :

> Hi：
>  I expect synchrodata between hbase 0.9 and hbase 1.2.
> What's more,I find several ways to do it.
> Follow :
> 1.replication (need modify)
> 2.sync hlog before delete to hdfs .oldlog (need modify)
> 3.client writes data to two hbase
>


> 4.client writes data to kafka and consume to two hbase
>
This is a good choice to satisfy your scenario.


> But, I think the bigest question is one java client how to use two
> hbase-cliet jar,It must be conflict,How can I do?
>

Hbase Question

[apple]

Hi：
 I expect synchrodata between hbase 0.9 and hbase 1.2.
What's more,I find several ways to do it.
Follow :
1.replication (need modify)
2.sync hlog before delete to hdfs .oldlog (need modify)
3.client writes data to two hbase
4.client writes data to kafka and consume to two hbase

But, I think the bigest question is one java client how to use two hbase-cliet 
jar,It must be conflict,How can I do?

Re: HBase Question

[Michael Segel]

Meh. 
Go to Hive instead. 


 On Mar 13, 2015, at 11:35 AM, Abraham Tom work2m...@gmail.com wrote:
 
 If you are comfortable with SQL
 I would look into Phoenix
 http://phoenix.apache.org/index.html
 
 
 On Thu, Mar 12, 2015 at 10:00 PM, Sudeep Pandey pandey.datat...@gmail.com
 wrote:
 
 Hello:
 
 If I am unable to do JAVA coding and prefer HBase shell for HBase
 works/interactions, will I be able to do all operations?
 i.e.
 
 Is JAVA coding (Client API) needed to do something in HBase which is not
 possible by HBase shell commands?
 
 Thank You,
 Sudeep Pandey
 Ph: 5107783972
 
 
 
 
 -- 
 Abraham Tom
 Email:   work2m...@gmail.com
 Phone:  415-515-3621

The opinions expressed here are mine, while they may reflect a cognitive 
thought, that is purely accidental. 
Use at your own risk. 
Michael Segel
michael_segel (AT) hotmail.com

Re: HBase Question

[Sean Busbey]

We usually try to have a shell way of doing all public facing operations.
In particular, I'd say if something shows up in the ref guide[1] without a
shell way to do it, I'd consider it a bug. The one big caveat is that the
shell is not performant for doing data inserts or fetching. Those functions
are really only set up in the shell for works-at-all operational testing.

Would working in a scripting language like python be easier? We have a
couple of options for accessing HBase from non-JVM languages.

[1]: http://hbase.apache.org/book.html

On Fri, Mar 13, 2015 at 12:00 AM, Sudeep Pandey pandey.datat...@gmail.com
wrote:

 Hello:

 If I am unable to do JAVA coding and prefer HBase shell for HBase
 works/interactions, will I be able to do all operations?
 i.e.

 Is JAVA coding (Client API) needed to do something in HBase which is not
 possible by HBase shell commands?

 Thank You,
 Sudeep Pandey
 Ph: 5107783972




-- 
Sean

HBase Question

[Sudeep Pandey]

Hello:

If I am unable to do JAVA coding and prefer HBase shell for HBase
works/interactions, will I be able to do all operations?
i.e.

Is JAVA coding (Client API) needed to do something in HBase which is not
possible by HBase shell commands?

Thank You,
Sudeep Pandey
Ph: 5107783972

Re: HBase Question

[Abraham Tom]

If you are comfortable with SQL
I would look into Phoenix
http://phoenix.apache.org/index.html


On Thu, Mar 12, 2015 at 10:00 PM, Sudeep Pandey pandey.datat...@gmail.com
wrote:

 Hello:

 If I am unable to do JAVA coding and prefer HBase shell for HBase
 works/interactions, will I be able to do all operations?
 i.e.

 Is JAVA coding (Client API) needed to do something in HBase which is not
 possible by HBase shell commands?

 Thank You,
 Sudeep Pandey
 Ph: 5107783972




-- 
Abraham Tom
Email:   work2m...@gmail.com
Phone:  415-515-3621

Re: HBase Question

[Jean-Marc Spaggiari]

Have you looked at the REST API? Can that be an option for you?
Le 2015-03-13 11:28, Sudeep Pandey pandey.datat...@gmail.com a écrit :

 Hello:

 If I am unable to do JAVA coding and prefer HBase shell for HBase
 works/interactions, will I be able to do all operations?
 i.e.

 Is JAVA coding (Client API) needed to do something in HBase which is not
 possible by HBase shell commands?

 Thank You,
 Sudeep Pandey
 Ph: 5107783972

Re: Hbase question

[Ted Yu]

HBase relies on hdfs features heavily.
HBase also  supports running Map Reduce Jobs.

You can find examples in these places (0.94 codebase):

./security/src/test/java/org/apache/hadoop/hbase/mapreduce
./src/examples/mapreduce/org/apache/hadoop/hbase/mapreduce
./src/main/java/org/apache/hadoop/hbase/mapreduce
./src/main/resources/org/apache/hadoop/hbase/mapreduce
./src/test/java/org/apache/hadoop/hbase/mapreduce

On Sun, Apr 21, 2013 at 12:53 AM, Rami Mankevich ra...@amdocs.com wrote:

 I have additional question:
 Hbase is built on top of hadoop.
 Does HBases uses HDFS only of hadoop or uses Map Reduce Jobs engine as
 well?
 Thanks a lot!


 From: Rami Mankevich
 Sent: Tuesday, April 09, 2013 8:52 PM
 To: 'user@hbase.apache.org'
 Cc: 'Andrew Purtell'
 Subject: RE: Hbase question

 First of all - thanks  for the quick response.

 Basically threads I want to open are for my own  internal structure
 updates and I guess have no relations to HBase internal structures.
 All I want is initiations for some asynchronous structure updates as part
 of coprocessor execution in order  not to block user reponse.

 The only reason I was asking is to be sure Hbase will not kill those
 threads.
 As I understand - shouldn't be any issue with that. Am I correct?

 In addition - Is there any Hbase Thread pool I can use?


 Thanks
 From: Andrew Purtell [mailto:apurt...@apache.org]mailto:[mailto:
 apurt...@apache.org]
 Sent: Tuesday, April 09, 2013 6:53 PM
 To: Rami Mankevich
 Cc: apurt...@apache.orgmailto:apurt...@apache.org
 Subject: Re: Hbase question

 Hi Rami,

 It is no problem to create threads in a coprocessor as a generic answer.
 More specifically there could be issues depending on exactly what you want
 to do, since coprocessor code changes HBase internals. Perhaps you could
 say a bit more. I also encourage you to ask this question on
 user@hbase.apache.orgmailto:user@hbase.apache.org so other contributors
 can chime in too.

 On Tuesday, April 9, 2013, Rami Mankevich wrote:
 Hey
 According to the Hbase documentation you are one of contrinuters to the
 HBase project
 I would like to raise some question when nobody can basically advice me:

 In context of coprocessors I want to raise some threads.
 Do you see any problems with that?

 Thanks
 This message and the information contained herein is proprietary and
 confidential and subject to the Amdocs policy statement, you may review at
 http://www.amdocs.com/email_disclaimer.asp


 --
 Best regards,

- Andy

 Problems worthy of attack prove their worth by hitting back. - Piet Hein
 (via Tom White)

Re: Hbase question

[shashwat shriparv]

HBase Serve the purpose if you use the HDFS underlying hbase, as it will
distribute, and also you can write hbase mapreduce code additional to the
hbase APIs. Please check following links for hbase mapreduce coding...

http://hbase.apache.org/book/mapreduce.example.html
http://hbase.apache.org/book/ops_mgt.html
http://hbase.apache.org/book/mapreduce.html


*Thanks  Regards*

∞
Shashwat Shriparv



On Sun, Apr 21, 2013 at 10:47 PM, Ted Yu yuzhih...@gmail.com wrote:

 HBase relies on hdfs features heavily.
 HBase also  supports running Map Reduce Jobs.

 You can find examples in these places (0.94 codebase):

 ./security/src/test/java/org/apache/hadoop/hbase/mapreduce
 ./src/examples/mapreduce/org/apache/hadoop/hbase/mapreduce
 ./src/main/java/org/apache/hadoop/hbase/mapreduce
 ./src/main/resources/org/apache/hadoop/hbase/mapreduce
 ./src/test/java/org/apache/hadoop/hbase/mapreduce

 On Sun, Apr 21, 2013 at 12:53 AM, Rami Mankevich ra...@amdocs.com wrote:

  I have additional question:
  Hbase is built on top of hadoop.
  Does HBases uses HDFS only of hadoop or uses Map Reduce Jobs engine as
  well?
  Thanks a lot!
 
 
  From: Rami Mankevich
  Sent: Tuesday, April 09, 2013 8:52 PM
  To: 'user@hbase.apache.org'
  Cc: 'Andrew Purtell'
  Subject: RE: Hbase question
 
  First of all - thanks  for the quick response.
 
  Basically threads I want to open are for my own  internal structure
  updates and I guess have no relations to HBase internal structures.
  All I want is initiations for some asynchronous structure updates as part
  of coprocessor execution in order  not to block user reponse.
 
  The only reason I was asking is to be sure Hbase will not kill those
  threads.
  As I understand - shouldn't be any issue with that. Am I correct?
 
  In addition - Is there any Hbase Thread pool I can use?
 
 
  Thanks
  From: Andrew Purtell [mailto:apurt...@apache.org]mailto:[mailto:
  apurt...@apache.org]
  Sent: Tuesday, April 09, 2013 6:53 PM
  To: Rami Mankevich
  Cc: apurt...@apache.orgmailto:apurt...@apache.org
  Subject: Re: Hbase question
 
  Hi Rami,
 
  It is no problem to create threads in a coprocessor as a generic answer.
  More specifically there could be issues depending on exactly what you
 want
  to do, since coprocessor code changes HBase internals. Perhaps you could
  say a bit more. I also encourage you to ask this question on
  user@hbase.apache.orgmailto:user@hbase.apache.org so other
 contributors
  can chime in too.
 
  On Tuesday, April 9, 2013, Rami Mankevich wrote:
  Hey
  According to the Hbase documentation you are one of contrinuters to the
  HBase project
  I would like to raise some question when nobody can basically advice me:
 
  In context of coprocessors I want to raise some threads.
  Do you see any problems with that?
 
  Thanks
  This message and the information contained herein is proprietary and
  confidential and subject to the Amdocs policy statement, you may review
 at
  http://www.amdocs.com/email_disclaimer.asp
 
 
  --
  Best regards,
 
 - Andy
 
  Problems worthy of attack prove their worth by hitting back. - Piet Hein
  (via Tom White)
 

Re: Hbase question

[Ted Yu]

Rami:
Can you tell us what coprocessor hook you plan to use ?

Thanks

On Tue, Apr 9, 2013 at 10:51 AM, Rami Mankevich ra...@amdocs.com wrote:

 First of all - thanks  for the quick response.

 Basically threads I want to open are for my own  internal structure
 updates and I guess have no relations to HBase internal structures.
 All I want is initiations for some asynchronous structure updates as part
 of coprocessor execution in order  not to block user reponse.

 The only reason I was asking is to be sure Hbase will not kill those
 threads.
 As I understand - shouldn't be any issue with that. Am I correct?

 In addition - Is there any Hbase Thread pool I can use?


 Thanks
 From: Andrew Purtell [mailto:apurt...@apache.org]
 Sent: Tuesday, April 09, 2013 6:53 PM
 To: Rami Mankevich
 Cc: apurt...@apache.org
 Subject: Re: Hbase question

 Hi Rami,

 It is no problem to create threads in a coprocessor as a generic answer.
 More specifically there could be issues depending on exactly what you want
 to do, since coprocessor code changes HBase internals. Perhaps you could
 say a bit more. I also encourage you to ask this question on
 user@hbase.apache.orgmailto:user@hbase.apache.org so other contributors
 can chime in too.

 On Tuesday, April 9, 2013, Rami Mankevich wrote:
 Hey
 According to the Hbase documentation you are one of contrinuters to the
 HBase project
 I would like to raise some question when nobody can basically advice me:

 In context of coprocessors I want to raise some threads.
 Do you see any problems with that?

 Thanks
 This message and the information contained herein is proprietary and
 confidential and subject to the Amdocs policy statement, you may review at
 http://www.amdocs.com/email_disclaimer.asp


 --
 Best regards,

- Andy

 Problems worthy of attack prove their worth by hitting back. - Piet Hein
 (via Tom White)

Re: Hbase question

[Gary Helmling]

Hi Rami,

One thing to note for RegionObservers, is that each table region gets its
own instance of each configured coprocessor.  So if your cluster has N
regions per region server, with your RegionObserver loaded on all tables,
then each region server will have N instances of your coprocessor.  You
should just be aware of this in case you, say, create a thread pool in your
coprocessor constructor.  An alternative in this case is to use a singleton
class per region server (aka per jvm) to manage the resources.

You do want to be sure that all threads are daemon threads, so that they
don't block region server shutdown.  Or else you'll need to ensure you
properly stop/join all the threads you've spawned on shutdown.
 RegionServerObserver.preStopRegionServer() may help there.

--gh



On Tue, Apr 9, 2013 at 11:40 AM, Ted Yu yuzhih...@gmail.com wrote:

 Rami:
 Can you tell us what coprocessor hook you plan to use ?

 Thanks

 On Tue, Apr 9, 2013 at 10:51 AM, Rami Mankevich ra...@amdocs.com wrote:

  First of all - thanks  for the quick response.
 
  Basically threads I want to open are for my own  internal structure
  updates and I guess have no relations to HBase internal structures.
  All I want is initiations for some asynchronous structure updates as part
  of coprocessor execution in order  not to block user reponse.
 
  The only reason I was asking is to be sure Hbase will not kill those
  threads.
  As I understand - shouldn't be any issue with that. Am I correct?
 
  In addition - Is there any Hbase Thread pool I can use?
 
 
  Thanks
  From: Andrew Purtell [mailto:apurt...@apache.org]
  Sent: Tuesday, April 09, 2013 6:53 PM
  To: Rami Mankevich
  Cc: apurt...@apache.org
  Subject: Re: Hbase question
 
  Hi Rami,
 
  It is no problem to create threads in a coprocessor as a generic answer.
  More specifically there could be issues depending on exactly what you
 want
  to do, since coprocessor code changes HBase internals. Perhaps you could
  say a bit more. I also encourage you to ask this question on
  user@hbase.apache.orgmailto:user@hbase.apache.org so other
 contributors
  can chime in too.
 
  On Tuesday, April 9, 2013, Rami Mankevich wrote:
  Hey
  According to the Hbase documentation you are one of contrinuters to the
  HBase project
  I would like to raise some question when nobody can basically advice me:
 
  In context of coprocessors I want to raise some threads.
  Do you see any problems with that?
 
  Thanks
  This message and the information contained herein is proprietary and
  confidential and subject to the Amdocs policy statement, you may review
 at
  http://www.amdocs.com/email_disclaimer.asp
 
 
  --
  Best regards,
 
 - Andy
 
  Problems worthy of attack prove their worth by hitting back. - Piet Hein
  (via Tom White)
 

Re: Hbase question

[Ted Yu]

Gary has provided nice summary of things to watch out for.

One more thing I want to mention is that care should be taken w.r.t.
coordinating the progress of the thread pool and normal region operations.
There're already many threads running in the region server JVM. Adding one
more thread pool may make resource consumption more complex.

What if the custom processing cannot keep up with the rate at which
asynchronous requests are queued ?

w.r.t. thread pool, you can refer to the following code in HRegion:

  ThreadPoolExecutor storeOpenerThreadPool =

getStoreOpenAndCloseThreadPool(

  StoreOpenerThread- + this.getRegionNameAsString());

  CompletionServiceHStore completionService =

new ExecutorCompletionServiceHStore(storeOpenerThreadPool);

Cheers

On Tue, Apr 9, 2013 at 11:57 AM, Gary Helmling ghelml...@gmail.com wrote:

 Hi Rami,

 One thing to note for RegionObservers, is that each table region gets its
 own instance of each configured coprocessor.  So if your cluster has N
 regions per region server, with your RegionObserver loaded on all tables,
 then each region server will have N instances of your coprocessor.  You
 should just be aware of this in case you, say, create a thread pool in your
 coprocessor constructor.  An alternative in this case is to use a singleton
 class per region server (aka per jvm) to manage the resources.

 You do want to be sure that all threads are daemon threads, so that they
 don't block region server shutdown.  Or else you'll need to ensure you
 properly stop/join all the threads you've spawned on shutdown.
  RegionServerObserver.preStopRegionServer() may help there.

 --gh



 On Tue, Apr 9, 2013 at 11:40 AM, Ted Yu yuzhih...@gmail.com wrote:

  Rami:
  Can you tell us what coprocessor hook you plan to use ?
 
  Thanks
 
  On Tue, Apr 9, 2013 at 10:51 AM, Rami Mankevich ra...@amdocs.com
 wrote:
 
   First of all - thanks  for the quick response.
  
   Basically threads I want to open are for my own  internal structure
   updates and I guess have no relations to HBase internal structures.
   All I want is initiations for some asynchronous structure updates as
 part
   of coprocessor execution in order  not to block user reponse.
  
   The only reason I was asking is to be sure Hbase will not kill those
   threads.
   As I understand - shouldn't be any issue with that. Am I correct?
  
   In addition - Is there any Hbase Thread pool I can use?
  
  
   Thanks
   From: Andrew Purtell [mailto:apurt...@apache.org]
   Sent: Tuesday, April 09, 2013 6:53 PM
   To: Rami Mankevich
   Cc: apurt...@apache.org
   Subject: Re: Hbase question
  
   Hi Rami,
  
   It is no problem to create threads in a coprocessor as a generic
 answer.
   More specifically there could be issues depending on exactly what you
  want
   to do, since coprocessor code changes HBase internals. Perhaps you
 could
   say a bit more. I also encourage you to ask this question on
   user@hbase.apache.orgmailto:user@hbase.apache.org so other
  contributors
   can chime in too.
  
   On Tuesday, April 9, 2013, Rami Mankevich wrote:
   Hey
   According to the Hbase documentation you are one of contrinuters to the
   HBase project
   I would like to raise some question when nobody can basically advice
 me:
  
   In context of coprocessors I want to raise some threads.
   Do you see any problems with that?
  
   Thanks
   This message and the information contained herein is proprietary and
   confidential and subject to the Amdocs policy statement, you may review
  at
   http://www.amdocs.com/email_disclaimer.asp
  
  
   --
   Best regards,
  
  - Andy
  
   Problems worthy of attack prove their worth by hitting back. - Piet
 Hein
   (via Tom White)
  
 

RE: Hbase Question

[Dalia Sobhy]

Dear yong,

How to 
distribute my data in the cluster ? Note that I am using cloudera manager 4.1

Thanks in advance:D

 Date: Fri, 28 Dec 2012 20:38:22 +0100
 Subject: Re: Hbase Question
 From: yongyong...@gmail.com
 To: user@hbase.apache.org
 
 I think you can take a look at your row-key design and evenly
 distribute your data in your cluster, as you mentioned even if you
 added more nodes, there was no improvement of performance. Maybe you
 have a node who is a hot spot, and the other nodes have no work to do.
 
 regards!
 
 Yong
 
 On Tue, Dec 25, 2012 at 3:31 AM, 周梦想 abloz...@gmail.com wrote:
  Hi Dalia,
 
  I think you can make a small sample of the table to do the test, then
  you'll find what's the difference of scan and count.
  because you can count it by human.
 
  Best regards,
  Andy
 
  2012/12/24 Dalia Sobhy dalia.mohso...@hotmail.com
 
 
  Dear all,
 
  I have 50,000 row with diagnosis qualifier = cardiac, and another 50,000
  rows with renal.
 
  When I type this in Hbase shell,
 
  import org.apache.hadoop.hbase.filter.CompareFilter
  import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
  import org.apache.hadoop.hbase.filter.SubstringComparator
  import org.apache.hadoop.hbase.util.Bytes
 
  scan 'patient', { COLUMNS = info:diagnosis, FILTER =
  SingleColumnValueFilter.new(Bytes.toBytes('info'),
   Bytes.toBytes('diagnosis'),
   CompareFilter::CompareOp.valueOf('EQUAL'),
   SubstringComparator.new('cardiac'))}
 
  Output = 50,000 row
 
  import org.apache.hadoop.hbase.filter.CompareFilter
  import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
  import org.apache.hadoop.hbase.filter.SubstringComparator
  import org.apache.hadoop.hbase.util.Bytes
 
  count 'patient', { COLUMNS = info:diagnosis, FILTER =
  SingleColumnValueFilter.new(Bytes.toBytes('info'),
   Bytes.toBytes('diagnosis'),
   CompareFilter::CompareOp.valueOf('EQUAL'),
   SubstringComparator.new('cardiac'))}
  Output = 100,000 row
 
  Even though I tried it using Hbase Java API, Aggregation Client Instance,
  and I enabled the Coprocessor aggregation for the table.
  rowCount = aggregationClient.rowCount(TABLE_NAME, null, scan)
 
  Also when measuring the improved performance on case of adding more nodes
  the operation takes the same time.
 
  So any advice please?
 
  I have been throughout all this mess from a couple of weeks
 
  Thanks,
 
 
 
 
  

Re: Hbase Question

[yonghu]

I think you can take a look at your row-key design and evenly
distribute your data in your cluster, as you mentioned even if you
added more nodes, there was no improvement of performance. Maybe you
have a node who is a hot spot, and the other nodes have no work to do.

regards!

Yong

On Tue, Dec 25, 2012 at 3:31 AM, 周梦想 abloz...@gmail.com wrote:
 Hi Dalia,

 I think you can make a small sample of the table to do the test, then
 you'll find what's the difference of scan and count.
 because you can count it by human.

 Best regards,
 Andy

 2012/12/24 Dalia Sobhy dalia.mohso...@hotmail.com


 Dear all,

 I have 50,000 row with diagnosis qualifier = cardiac, and another 50,000
 rows with renal.

 When I type this in Hbase shell,

 import org.apache.hadoop.hbase.filter.CompareFilter
 import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
 import org.apache.hadoop.hbase.filter.SubstringComparator
 import org.apache.hadoop.hbase.util.Bytes

 scan 'patient', { COLUMNS = info:diagnosis, FILTER =
 SingleColumnValueFilter.new(Bytes.toBytes('info'),
  Bytes.toBytes('diagnosis'),
  CompareFilter::CompareOp.valueOf('EQUAL'),
  SubstringComparator.new('cardiac'))}

 Output = 50,000 row

 import org.apache.hadoop.hbase.filter.CompareFilter
 import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
 import org.apache.hadoop.hbase.filter.SubstringComparator
 import org.apache.hadoop.hbase.util.Bytes

 count 'patient', { COLUMNS = info:diagnosis, FILTER =
 SingleColumnValueFilter.new(Bytes.toBytes('info'),
  Bytes.toBytes('diagnosis'),
  CompareFilter::CompareOp.valueOf('EQUAL'),
  SubstringComparator.new('cardiac'))}
 Output = 100,000 row

 Even though I tried it using Hbase Java API, Aggregation Client Instance,
 and I enabled the Coprocessor aggregation for the table.
 rowCount = aggregationClient.rowCount(TABLE_NAME, null, scan)

 Also when measuring the improved performance on case of adding more nodes
 the operation takes the same time.

 So any advice please?

 I have been throughout all this mess from a couple of weeks

 Thanks,

Re: Hbase Question

[周梦想]

Hi Dalia,

I think you can make a small sample of the table to do the test, then
you'll find what's the difference of scan and count.
because you can count it by human.

Best regards,
Andy

2012/12/24 Dalia Sobhy dalia.mohso...@hotmail.com


 Dear all,

 I have 50,000 row with diagnosis qualifier = cardiac, and another 50,000
 rows with renal.

 When I type this in Hbase shell,

 import org.apache.hadoop.hbase.filter.CompareFilter
 import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
 import org.apache.hadoop.hbase.filter.SubstringComparator
 import org.apache.hadoop.hbase.util.Bytes

 scan 'patient', { COLUMNS = info:diagnosis, FILTER =
 SingleColumnValueFilter.new(Bytes.toBytes('info'),
  Bytes.toBytes('diagnosis'),
  CompareFilter::CompareOp.valueOf('EQUAL'),
  SubstringComparator.new('cardiac'))}

 Output = 50,000 row

 import org.apache.hadoop.hbase.filter.CompareFilter
 import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
 import org.apache.hadoop.hbase.filter.SubstringComparator
 import org.apache.hadoop.hbase.util.Bytes

 count 'patient', { COLUMNS = info:diagnosis, FILTER =
 SingleColumnValueFilter.new(Bytes.toBytes('info'),
  Bytes.toBytes('diagnosis'),
  CompareFilter::CompareOp.valueOf('EQUAL'),
  SubstringComparator.new('cardiac'))}
 Output = 100,000 row

 Even though I tried it using Hbase Java API, Aggregation Client Instance,
 and I enabled the Coprocessor aggregation for the table.
 rowCount = aggregationClient.rowCount(TABLE_NAME, null, scan)

 Also when measuring the improved performance on case of adding more nodes
 the operation takes the same time.

 So any advice please?

 I have been throughout all this mess from a couple of weeks

 Thanks,

Hbase Question

[Dalia Sobhy]

Dear all,

I have 50,000 row with diagnosis qualifier = cardiac, and another 50,000 rows 
with renal.

When I type this in Hbase shell,

import org.apache.hadoop.hbase.filter.CompareFilter
import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
import org.apache.hadoop.hbase.filter.SubstringComparator
import org.apache.hadoop.hbase.util.Bytes

scan 'patient', { COLUMNS = info:diagnosis, FILTER =
SingleColumnValueFilter.new(Bytes.toBytes('info'),
 Bytes.toBytes('diagnosis'),
 CompareFilter::CompareOp.valueOf('EQUAL'),
 SubstringComparator.new('cardiac'))}

Output = 50,000 row

import org.apache.hadoop.hbase.filter.CompareFilter
import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
import org.apache.hadoop.hbase.filter.SubstringComparator
import org.apache.hadoop.hbase.util.Bytes

count 'patient', { COLUMNS = info:diagnosis, FILTER =
SingleColumnValueFilter.new(Bytes.toBytes('info'),
 Bytes.toBytes('diagnosis'),
 CompareFilter::CompareOp.valueOf('EQUAL'),
 SubstringComparator.new('cardiac'))}
Output = 100,000 row

Even though I tried it using Hbase Java API, Aggregation Client Instance, and I 
enabled the Coprocessor aggregation for the table.
rowCount = aggregationClient.rowCount(TABLE_NAME, null, scan)

Also when measuring the improved performance on case of adding more nodes the 
operation takes the same time.

So any advice please?

I have been throughout all this mess from a couple of weeks

Thanks,


 
  

HBase question

[King JKing]

Dear all,

I want to design Follower schema like Twitter. I have 2 design

Design 1:
userId{//rowkey
followerId: time,
}


Design 2 :
[userId][followerId]{//rowkey
time: time
}

I have 2 question:
1. Does HBase support scan data of rowkey by column?
2. Which design is better? I think that design 2 is better when user have
large amount of follower.

Thank a lot for support.

Best regards,
BeUKing.

Re: HBase question

[Jean-Daniel Cryans]

 I have 2 question:
 1. Does HBase support scan data of rowkey by column?

You mean secondary indexes? No:
http://hbase.apache.org/book.html#secondary.indices

 2. Which design is better? I think that design 2 is better when user have
 large amount of follower.

I cover a bunch of designs in this very recent thread:
http://search-hadoop.com/m/AXRdP1KKR5T1

J-D