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Posted to user@hbase.apache.org by "Edward J. Yoon" <ed...@apache.org> on 2009/04/29 09:52:39 UTC
Force split
Hi,
I saw that function on the web UI but it seems not implemented yet.
public void modifyTable(final byte[] tableName, int op, Writable[] args)
switch (op) {
...
case MODIFY_TABLE_SPLIT:
case MODIFY_TABLE_COMPACT:
..
}
}
Am I right? Pls let me know if i'm wrong.
--
Best Regards, Edward J. Yoon @ NHN, corp.
edwardyoon@apache.org
http://blog.udanax.org
Re: Force split
Posted by "Edward J. Yoon" <ed...@apache.org>.
Hi Andy, Thanks for your information!
On Wed, Apr 29, 2009 at 10:29 PM, Andrew Purtell <ap...@apache.org> wrote:
>
> Hi Edward. You still have DFS issues. Have you
> followed the DFS related troubleshooting tips on the
> troubleshooting page of the HBase wiki? Have you
> considered adding more data nodes?
>
> - Andy
>
>> From: Edward J. Yoon
>> Subject: Re: Force split
>> To: hbase-user@hadoop.apache.org
>> Date: Wednesday, April 29, 2009, 2:55 AM
>> I found below error message. :(
>>
>> 2009-04-29 16:16:57,380 WARN
>> org.apache.hadoop.hdfs.DFSClient: Could
>> not get block locations. Aborting...
>> 2009-04-29 16:16:57,390 ERROR
>> org.apache.hadoop.hbase.regionserver.CompactSplitThread:
>> Compaction/Split failed for region
>> SparseMatrix_randufgse,000000000002519,1240989321368
>> java.io.IOException: Could not read from stream
>> at
>> org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:119)
>> at
>> java.io.DataInputStream.readByte(DataInputStream.java:248)
>> at
>> org.apache.hadoop.io.WritableUtils.readVLong(WritableUtils.java:325)
>> at
>> org.apache.hadoop.io.WritableUtils.readVInt(WritableUtils.java:346)
>> at
>> org.apache.hadoop.io.Text.readString(Text.java:400)
>> at
>> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.createBlockOutputStream(DFSClient.java:2779)
>> at
>> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.nextBlockOutputStream(DFSClient.java:2704)
>> at
>> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.access$2000(DFSClient.java:1997)
>> at
>> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:2183)
>> 2009-04-29 16:18:46,051 INFO
>> org.apache.hadoop.io.compress.CodecPool:
>> Got brand-new decompressor
>> 2009-04-29 16:18:46,051 INFO
>> org.apache.hadoop.io.compress.CodecPool:
>> Got brand-new decompressor
>>
>>
>> On Wed, Apr 29, 2009 at 6:17 PM, Edward J. Yoon
>> <ed...@apache.org> wrote:
>> > According to my understanding, there is no any code
>> for
>> > MODIFY_TABLE_SPLIT and table.jsp work as below.
>> >
>> > Writable[] arr = new Writable[1];
>> > arr[0] = new
>> ImmutableBytesWritable(Bytes.toBytes(key));
>> > master.modifyTable(Bytes.toBytes(tableName),
>> > HConstants.MODIFY_TABLE_SPLIT, arr);
>> >
>> > Anyway, I'd like to know how to force split.
>> > Below is the info of 'Regions in randufgse'
>> page.
>> > Rows are sequntial numbers between 0 and 10,000.
>> >
>> > If I want to split by "000000000007648"
>> then,
>> >
>> > master.modifyTable(Bytes.toBytes(tableName),
>> > HConstants.MODIFY_TABLE_SPLIT, new
>> >
>> ImmutableBytesWritable(Bytes.toBytes("000000000007648"));
>> >
>> > Is enough?
>> >
>> > d8g055.nhncorp.com:60020: , 000000000000465
>> > a50891.nhncorp.com:60020: 000000000000465,
>> 000000000000811
>> > a51019.nhncorp.com:60020: 000000000000811,
>> 000000000001134
>> > a51019.nhncorp.com:60020: 000000000001134,
>> 000000000001460
>> > a51010.nhncorp.com:60020: 000000000001460,
>> 000000000001723
>> > a51010.nhncorp.com:60020: 000000000001723,
>> 000000000001988
>> > a51018.nhncorp.com:60020: 000000000001988,
>> 000000000002254
>> > a51018.nhncorp.com:60020: 000000000002254,
>> 000000000002519
>> > a50837.nhncorp.com:60020: 000000000002519,
>> 000000000004648
>> > a50837.nhncorp.com:60020: 000000000004648,
>> >
>> > On Wed, Apr 29, 2009 at 5:11 PM, Ryan Rawson
>> <ry...@gmail.com> wrote:
>> >> It works, it has worked in the past...
>> >>
>> >> One thing to remember is you can't always
>> split... You cant split until all
>> >> the open scanners are closed. Furthermore you
>> can't split if a region has
>> >> just split. The reason for this is because once
>> you split a region, files
>> >> aren't rewritten, but the 2 daughter regions
>> hold references to the parent
>> >> region. Until those regions are resolved via
>> compaction (slow, minutes
>> >> possibly), you can't split those daughter
>> regions.
>> >>
>> >> So check again, maybe your splits are working
>> after all.
>> >>
>> >> If you are doing imports, check out my
>> Randomize.java i posted to the list
>> >> last week. That helps import performance
>> substantially.
>> >>
>> >> On Wed, Apr 29, 2009 at 12:52 AM, Edward J. Yoon
>> <ed...@apache.org>wrote:
>> >>
>> >>> Hi,
>> >>>
>> >>> I saw that function on the web UI but it seems
>> not implemented yet.
>> >>>
>> >>> public void modifyTable(final byte[]
>> tableName, int op, Writable[] args)
>> >>> switch (op) {
>> >>> ...
>> >>> case MODIFY_TABLE_SPLIT:
>> >>> case MODIFY_TABLE_COMPACT:
>> >>> ..
>> >>> }
>> >>> }
>> >>>
>> >>> Am I right? Pls let me know if i'm wrong.
>> >>> --
>> >>> Best Regards, Edward J. Yoon @ NHN, corp.
>> >>> edwardyoon@apache.org
>> >>> http://blog.udanax.org
>> >>>
>> >>
>> >
>> >
>> >
>> > --
>> > Best Regards, Edward J. Yoon @ NHN, corp.
>> > edwardyoon@apache.org
>> > http://blog.udanax.org
>> >
>>
>>
>>
>> --
>> Best Regards, Edward J. Yoon @ NHN, corp.
>> edwardyoon@apache.org
>> http://blog.udanax.org
>
>
>
>
--
Best Regards, Edward J. Yoon @ NHN, corp.
edwardyoon@apache.org
http://blog.udanax.org
Re: Force split
Posted by Andrew Purtell <ap...@apache.org>.
Hi Edward. You still have DFS issues. Have you
followed the DFS related troubleshooting tips on the
troubleshooting page of the HBase wiki? Have you
considered adding more data nodes?
- Andy
> From: Edward J. Yoon
> Subject: Re: Force split
> To: hbase-user@hadoop.apache.org
> Date: Wednesday, April 29, 2009, 2:55 AM
> I found below error message. :(
>
> 2009-04-29 16:16:57,380 WARN
> org.apache.hadoop.hdfs.DFSClient: Could
> not get block locations. Aborting...
> 2009-04-29 16:16:57,390 ERROR
> org.apache.hadoop.hbase.regionserver.CompactSplitThread:
> Compaction/Split failed for region
> SparseMatrix_randufgse,000000000002519,1240989321368
> java.io.IOException: Could not read from stream
> at
> org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:119)
> at
> java.io.DataInputStream.readByte(DataInputStream.java:248)
> at
> org.apache.hadoop.io.WritableUtils.readVLong(WritableUtils.java:325)
> at
> org.apache.hadoop.io.WritableUtils.readVInt(WritableUtils.java:346)
> at
> org.apache.hadoop.io.Text.readString(Text.java:400)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.createBlockOutputStream(DFSClient.java:2779)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.nextBlockOutputStream(DFSClient.java:2704)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.access$2000(DFSClient.java:1997)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:2183)
> 2009-04-29 16:18:46,051 INFO
> org.apache.hadoop.io.compress.CodecPool:
> Got brand-new decompressor
> 2009-04-29 16:18:46,051 INFO
> org.apache.hadoop.io.compress.CodecPool:
> Got brand-new decompressor
>
>
> On Wed, Apr 29, 2009 at 6:17 PM, Edward J. Yoon
> <ed...@apache.org> wrote:
> > According to my understanding, there is no any code
> for
> > MODIFY_TABLE_SPLIT and table.jsp work as below.
> >
> > Writable[] arr = new Writable[1];
> > arr[0] = new
> ImmutableBytesWritable(Bytes.toBytes(key));
> > master.modifyTable(Bytes.toBytes(tableName),
> > HConstants.MODIFY_TABLE_SPLIT, arr);
> >
> > Anyway, I'd like to know how to force split.
> > Below is the info of 'Regions in randufgse'
> page.
> > Rows are sequntial numbers between 0 and 10,000.
> >
> > If I want to split by "000000000007648"
> then,
> >
> > master.modifyTable(Bytes.toBytes(tableName),
> > HConstants.MODIFY_TABLE_SPLIT, new
> >
> ImmutableBytesWritable(Bytes.toBytes("000000000007648"));
> >
> > Is enough?
> >
> > d8g055.nhncorp.com:60020: , 000000000000465
> > a50891.nhncorp.com:60020: 000000000000465,
> 000000000000811
> > a51019.nhncorp.com:60020: 000000000000811,
> 000000000001134
> > a51019.nhncorp.com:60020: 000000000001134,
> 000000000001460
> > a51010.nhncorp.com:60020: 000000000001460,
> 000000000001723
> > a51010.nhncorp.com:60020: 000000000001723,
> 000000000001988
> > a51018.nhncorp.com:60020: 000000000001988,
> 000000000002254
> > a51018.nhncorp.com:60020: 000000000002254,
> 000000000002519
> > a50837.nhncorp.com:60020: 000000000002519,
> 000000000004648
> > a50837.nhncorp.com:60020: 000000000004648,
> >
> > On Wed, Apr 29, 2009 at 5:11 PM, Ryan Rawson
> <ry...@gmail.com> wrote:
> >> It works, it has worked in the past...
> >>
> >> One thing to remember is you can't always
> split... You cant split until all
> >> the open scanners are closed. Furthermore you
> can't split if a region has
> >> just split. The reason for this is because once
> you split a region, files
> >> aren't rewritten, but the 2 daughter regions
> hold references to the parent
> >> region. Until those regions are resolved via
> compaction (slow, minutes
> >> possibly), you can't split those daughter
> regions.
> >>
> >> So check again, maybe your splits are working
> after all.
> >>
> >> If you are doing imports, check out my
> Randomize.java i posted to the list
> >> last week. That helps import performance
> substantially.
> >>
> >> On Wed, Apr 29, 2009 at 12:52 AM, Edward J. Yoon
> <ed...@apache.org>wrote:
> >>
> >>> Hi,
> >>>
> >>> I saw that function on the web UI but it seems
> not implemented yet.
> >>>
> >>> public void modifyTable(final byte[]
> tableName, int op, Writable[] args)
> >>> switch (op) {
> >>> ...
> >>> case MODIFY_TABLE_SPLIT:
> >>> case MODIFY_TABLE_COMPACT:
> >>> ..
> >>> }
> >>> }
> >>>
> >>> Am I right? Pls let me know if i'm wrong.
> >>> --
> >>> Best Regards, Edward J. Yoon @ NHN, corp.
> >>> edwardyoon@apache.org
> >>> http://blog.udanax.org
> >>>
> >>
> >
> >
> >
> > --
> > Best Regards, Edward J. Yoon @ NHN, corp.
> > edwardyoon@apache.org
> > http://blog.udanax.org
> >
>
>
>
> --
> Best Regards, Edward J. Yoon @ NHN, corp.
> edwardyoon@apache.org
> http://blog.udanax.org
Re: Force split
Posted by "Edward J. Yoon" <ed...@apache.org>.
I found below error message. :(
2009-04-29 16:16:57,380 WARN org.apache.hadoop.hdfs.DFSClient: Could
not get block locations. Aborting...
2009-04-29 16:16:57,390 ERROR
org.apache.hadoop.hbase.regionserver.CompactSplitThread:
Compaction/Split failed for region
SparseMatrix_randufgse,000000000002519,1240989321368
java.io.IOException: Could not read from stream
at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:119)
at java.io.DataInputStream.readByte(DataInputStream.java:248)
at org.apache.hadoop.io.WritableUtils.readVLong(WritableUtils.java:325)
at org.apache.hadoop.io.WritableUtils.readVInt(WritableUtils.java:346)
at org.apache.hadoop.io.Text.readString(Text.java:400)
at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.createBlockOutputStream(DFSClient.java:2779)
at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.nextBlockOutputStream(DFSClient.java:2704)
at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.access$2000(DFSClient.java:1997)
at org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:2183)
2009-04-29 16:18:46,051 INFO org.apache.hadoop.io.compress.CodecPool:
Got brand-new decompressor
2009-04-29 16:18:46,051 INFO org.apache.hadoop.io.compress.CodecPool:
Got brand-new decompressor
On Wed, Apr 29, 2009 at 6:17 PM, Edward J. Yoon <ed...@apache.org> wrote:
> According to my understanding, there is no any code for
> MODIFY_TABLE_SPLIT and table.jsp work as below.
>
> Writable[] arr = new Writable[1];
> arr[0] = new ImmutableBytesWritable(Bytes.toBytes(key));
> master.modifyTable(Bytes.toBytes(tableName),
> HConstants.MODIFY_TABLE_SPLIT, arr);
>
> Anyway, I'd like to know how to force split.
> Below is the info of 'Regions in randufgse' page.
> Rows are sequntial numbers between 0 and 10,000.
>
> If I want to split by "000000000007648" then,
>
> master.modifyTable(Bytes.toBytes(tableName),
> HConstants.MODIFY_TABLE_SPLIT, new
> ImmutableBytesWritable(Bytes.toBytes("000000000007648"));
>
> Is enough?
>
> d8g055.nhncorp.com:60020: , 000000000000465
> a50891.nhncorp.com:60020: 000000000000465, 000000000000811
> a51019.nhncorp.com:60020: 000000000000811, 000000000001134
> a51019.nhncorp.com:60020: 000000000001134, 000000000001460
> a51010.nhncorp.com:60020: 000000000001460, 000000000001723
> a51010.nhncorp.com:60020: 000000000001723, 000000000001988
> a51018.nhncorp.com:60020: 000000000001988, 000000000002254
> a51018.nhncorp.com:60020: 000000000002254, 000000000002519
> a50837.nhncorp.com:60020: 000000000002519, 000000000004648
> a50837.nhncorp.com:60020: 000000000004648,
>
> On Wed, Apr 29, 2009 at 5:11 PM, Ryan Rawson <ry...@gmail.com> wrote:
>> It works, it has worked in the past...
>>
>> One thing to remember is you can't always split... You cant split until all
>> the open scanners are closed. Furthermore you can't split if a region has
>> just split. The reason for this is because once you split a region, files
>> aren't rewritten, but the 2 daughter regions hold references to the parent
>> region. Until those regions are resolved via compaction (slow, minutes
>> possibly), you can't split those daughter regions.
>>
>> So check again, maybe your splits are working after all.
>>
>> If you are doing imports, check out my Randomize.java i posted to the list
>> last week. That helps import performance substantially.
>>
>> On Wed, Apr 29, 2009 at 12:52 AM, Edward J. Yoon <ed...@apache.org>wrote:
>>
>>> Hi,
>>>
>>> I saw that function on the web UI but it seems not implemented yet.
>>>
>>> public void modifyTable(final byte[] tableName, int op, Writable[] args)
>>> switch (op) {
>>> ...
>>> case MODIFY_TABLE_SPLIT:
>>> case MODIFY_TABLE_COMPACT:
>>> ..
>>> }
>>> }
>>>
>>> Am I right? Pls let me know if i'm wrong.
>>> --
>>> Best Regards, Edward J. Yoon @ NHN, corp.
>>> edwardyoon@apache.org
>>> http://blog.udanax.org
>>>
>>
>
>
>
> --
> Best Regards, Edward J. Yoon @ NHN, corp.
> edwardyoon@apache.org
> http://blog.udanax.org
>
--
Best Regards, Edward J. Yoon @ NHN, corp.
edwardyoon@apache.org
http://blog.udanax.org
Fwd: Force split
Posted by "Edward J. Yoon" <ed...@apache.org>.
In hbase, There is a force split function. We may want to use this as
a pre-conditioner.
---------- Forwarded message ----------
From: Edward J. Yoon <ed...@apache.org>
Date: Wed, Apr 29, 2009 at 6:17 PM
Subject: Re: Force split
To: hbase-user@hadoop.apache.org
According to my understanding, there is no any code for
MODIFY_TABLE_SPLIT and table.jsp work as below.
Writable[] arr = new Writable[1];
arr[0] = new ImmutableBytesWritable(Bytes.toBytes(key));
master.modifyTable(Bytes.toBytes(tableName),
HConstants.MODIFY_TABLE_SPLIT, arr);
Anyway, I'd like to know how to force split.
Below is the info of 'Regions in randufgse' page.
Rows are sequntial numbers between 0 and 10,000.
If I want to split by "000000000007648" then,
master.modifyTable(Bytes.toBytes(tableName),
HConstants.MODIFY_TABLE_SPLIT, new
ImmutableBytesWritable(Bytes.toBytes("000000000007648"));
Is enough?
d8g055.nhncorp.com:60020: , 000000000000465
a50891.nhncorp.com:60020: 000000000000465, 000000000000811
a51019.nhncorp.com:60020: 000000000000811, 000000000001134
a51019.nhncorp.com:60020: 000000000001134, 000000000001460
a51010.nhncorp.com:60020: 000000000001460, 000000000001723
a51010.nhncorp.com:60020: 000000000001723, 000000000001988
a51018.nhncorp.com:60020: 000000000001988, 000000000002254
a51018.nhncorp.com:60020: 000000000002254, 000000000002519
a50837.nhncorp.com:60020: 000000000002519, 000000000004648
a50837.nhncorp.com:60020: 000000000004648,
On Wed, Apr 29, 2009 at 5:11 PM, Ryan Rawson <ry...@gmail.com> wrote:
> It works, it has worked in the past...
>
> One thing to remember is you can't always split... You cant split until all
> the open scanners are closed. Furthermore you can't split if a region has
> just split. The reason for this is because once you split a region, files
> aren't rewritten, but the 2 daughter regions hold references to the parent
> region. Until those regions are resolved via compaction (slow, minutes
> possibly), you can't split those daughter regions.
>
> So check again, maybe your splits are working after all.
>
> If you are doing imports, check out my Randomize.java i posted to the list
> last week. That helps import performance substantially.
>
> On Wed, Apr 29, 2009 at 12:52 AM, Edward J. Yoon <ed...@apache.org>wrote:
>
>> Hi,
>>
>> I saw that function on the web UI but it seems not implemented yet.
>>
>> public void modifyTable(final byte[] tableName, int op, Writable[] args)
>> switch (op) {
>> ...
>> case MODIFY_TABLE_SPLIT:
>> case MODIFY_TABLE_COMPACT:
>> ..
>> }
>> }
>>
>> Am I right? Pls let me know if i'm wrong.
>> --
>> Best Regards, Edward J. Yoon @ NHN, corp.
>> edwardyoon@apache.org
>> http://blog.udanax.org
>>
>
--
Best Regards, Edward J. Yoon @ NHN, corp.
edwardyoon@apache.org
http://blog.udanax.org
--
Best Regards, Edward J. Yoon @ NHN, corp.
edwardyoon@apache.org
http://blog.udanax.org
Re: Force split
Posted by "Edward J. Yoon" <ed...@apache.org>.
According to my understanding, there is no any code for
MODIFY_TABLE_SPLIT and table.jsp work as below.
Writable[] arr = new Writable[1];
arr[0] = new ImmutableBytesWritable(Bytes.toBytes(key));
master.modifyTable(Bytes.toBytes(tableName),
HConstants.MODIFY_TABLE_SPLIT, arr);
Anyway, I'd like to know how to force split.
Below is the info of 'Regions in randufgse' page.
Rows are sequntial numbers between 0 and 10,000.
If I want to split by "000000000007648" then,
master.modifyTable(Bytes.toBytes(tableName),
HConstants.MODIFY_TABLE_SPLIT, new
ImmutableBytesWritable(Bytes.toBytes("000000000007648"));
Is enough?
d8g055.nhncorp.com:60020: , 000000000000465
a50891.nhncorp.com:60020: 000000000000465, 000000000000811
a51019.nhncorp.com:60020: 000000000000811, 000000000001134
a51019.nhncorp.com:60020: 000000000001134, 000000000001460
a51010.nhncorp.com:60020: 000000000001460, 000000000001723
a51010.nhncorp.com:60020: 000000000001723, 000000000001988
a51018.nhncorp.com:60020: 000000000001988, 000000000002254
a51018.nhncorp.com:60020: 000000000002254, 000000000002519
a50837.nhncorp.com:60020: 000000000002519, 000000000004648
a50837.nhncorp.com:60020: 000000000004648,
On Wed, Apr 29, 2009 at 5:11 PM, Ryan Rawson <ry...@gmail.com> wrote:
> It works, it has worked in the past...
>
> One thing to remember is you can't always split... You cant split until all
> the open scanners are closed. Furthermore you can't split if a region has
> just split. The reason for this is because once you split a region, files
> aren't rewritten, but the 2 daughter regions hold references to the parent
> region. Until those regions are resolved via compaction (slow, minutes
> possibly), you can't split those daughter regions.
>
> So check again, maybe your splits are working after all.
>
> If you are doing imports, check out my Randomize.java i posted to the list
> last week. That helps import performance substantially.
>
> On Wed, Apr 29, 2009 at 12:52 AM, Edward J. Yoon <ed...@apache.org>wrote:
>
>> Hi,
>>
>> I saw that function on the web UI but it seems not implemented yet.
>>
>> public void modifyTable(final byte[] tableName, int op, Writable[] args)
>> switch (op) {
>> ...
>> case MODIFY_TABLE_SPLIT:
>> case MODIFY_TABLE_COMPACT:
>> ..
>> }
>> }
>>
>> Am I right? Pls let me know if i'm wrong.
>> --
>> Best Regards, Edward J. Yoon @ NHN, corp.
>> edwardyoon@apache.org
>> http://blog.udanax.org
>>
>
--
Best Regards, Edward J. Yoon @ NHN, corp.
edwardyoon@apache.org
http://blog.udanax.org
Re: Force split
Posted by Ryan Rawson <ry...@gmail.com>.
It works, it has worked in the past...
One thing to remember is you can't always split... You cant split until all
the open scanners are closed. Furthermore you can't split if a region has
just split. The reason for this is because once you split a region, files
aren't rewritten, but the 2 daughter regions hold references to the parent
region. Until those regions are resolved via compaction (slow, minutes
possibly), you can't split those daughter regions.
So check again, maybe your splits are working after all.
If you are doing imports, check out my Randomize.java i posted to the list
last week. That helps import performance substantially.
On Wed, Apr 29, 2009 at 12:52 AM, Edward J. Yoon <ed...@apache.org>wrote:
> Hi,
>
> I saw that function on the web UI but it seems not implemented yet.
>
> public void modifyTable(final byte[] tableName, int op, Writable[] args)
> switch (op) {
> ...
> case MODIFY_TABLE_SPLIT:
> case MODIFY_TABLE_COMPACT:
> ..
> }
> }
>
> Am I right? Pls let me know if i'm wrong.
> --
> Best Regards, Edward J. Yoon @ NHN, corp.
> edwardyoon@apache.org
> http://blog.udanax.org
>