Re: Multiple region servers on the same host
One downside is that when the machine crashes, you would lose more than one region server. You may need to subclass RSGroupBasedLoadBalancer so that balancing decision fits your requirement. Cheers On Tue, Aug 23, 2016 at 4:53 PM, GuangYang wrote: > Hello,We are recently exploring running multiple region servers on the > same host, some of the potential benefits:1. smaller region server > instance, thus potential less contention for better performance?2. We are > running region server groups, thus we can run region server groups with > different workloads on the same group of hardware. > We plan to go with cgroups to isolate region servers on the same host, > mainly because we have had good experience using cgroups within other > hadoop projects. > Has anyone played around with running multiple RS on the same host and > would like to share the experience? > Thanks,Guang
Upgrade path from 1.1.0 to 1.2.2
Can we directly upgrade HBase from 1.1.0 to 1.2.2 being from minor version to another minor patch version, just checking whether it can be done.? Planning to follow below steps, 1.Install 1.2.2. 2. Gracefully shutdown 1.1.0. 3. Start 1.2.2. version. Do you see any harm in doing this? -- View this message in context: http://apache-hbase.679495.n3.nabble.com/Upgrade-path-from-1-1-0-to-1-2-2-tp4082050.html Sent from the HBase User mailing list archive at Nabble.com.
Re: Upgrade path from 1.1.0 to 1.2.2
You should be able to do rolling upgrade. Cheers > On Aug 24, 2016, at 3:32 AM, ssharavanan wrote: > > Can we directly upgrade HBase from 1.1.0 to 1.2.2 being from minor version to > another minor patch version, just checking whether it can be done.? > > Planning to follow below steps, > 1.Install 1.2.2. > 2. Gracefully shutdown 1.1.0. > 3. Start 1.2.2. version. > > Do you see any harm in doing this? > > > > > > > -- > View this message in context: > http://apache-hbase.679495.n3.nabble.com/Upgrade-path-from-1-1-0-to-1-2-2-tp4082050.html > Sent from the HBase User mailing list archive at Nabble.com.
How to Speed up Prefix scan on column qualifier
Hi All,
I have below code where I have row key like 9865327845_#RandomChar
I want to perform prefix scan I tryed with ResultScanner which has
performance impact
I have seen in some articles people saying about Get and setFilter but its
not working
can anyone suggest me better way, below is my code
public static HashSet getResultByPreFixFilterScan(String rowkeys){
Scan scan = new Scan();
PrefixFilter prefixFilter = new PrefixFilter(rowkeys.getBytes());
scan.setFilter(prefixFilter);
ResultScanner resultScanner = null;
try {
resultScanner = hTable.getScanner(scan);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
HashSet rowKeySet=new HashSet();
//Result result = table.get(g);
for (Result results : resultScanner) {
for(KeyValue kv : results.raw()){
rowKeySet.add(new String(kv.getRow()));
}
}
return rowKeySet;
}
can we perform prefix by
Filter filter = new QualifierFilter(CompareFilter.CompareOp.EQUAL, new
BinaryComparator(Bytes.toBytes(rowkeys)));
Thanks
Manjeet
--
luv all
Re: How to Speed up Prefix scan on column qualifier
Please use the following API to set start row before calling
hTable.getScanner(scan):
public Scan setStartRow(byte [] startRow) {
On Wed, Aug 24, 2016 at 5:08 AM, Manjeet Singh
wrote:
> Hi All,
>
> I have below code where I have row key like 9865327845_#RandomChar
> I want to perform prefix scan I tryed with ResultScanner which has
> performance impact
> I have seen in some articles people saying about Get and setFilter but its
> not working
> can anyone suggest me better way, below is my code
>
> public static HashSet getResultByPreFixFilterScan(String rowkeys){
> Scan scan = new Scan();
> PrefixFilter prefixFilter = new PrefixFilter(rowkeys.getBytes());
> scan.setFilter(prefixFilter);
> ResultScanner resultScanner = null;
> try {
> resultScanner = hTable.getScanner(scan);
> } catch (IOException e) {
> // TODO Auto-generated catch block
> e.printStackTrace();
> }
>
> HashSet rowKeySet=new HashSet();
> //Result result = table.get(g);
> for (Result results : resultScanner) {
> for(KeyValue kv : results.raw()){
> rowKeySet.add(new String(kv.getRow()));
>
> }
> }
> return rowKeySet;
> }
>
>
>
>
>
> can we perform prefix by
> Filter filter = new QualifierFilter(CompareFilter.CompareOp.EQUAL, new
> BinaryComparator(Bytes.toBytes(rowkeys)));
>
> Thanks
> Manjeet
>
> --
> luv all
>
Re: Upgrade path from 1.1.0 to 1.2.2
Thank you very much!!! -- View this message in context: http://apache-hbase.679495.n3.nabble.com/Upgrade-path-from-1-1-0-to-1-2-2-tp4082050p4082056.html Sent from the HBase User mailing list archive at Nabble.com.
Re: How to Speed up Prefix scan on column qualifier
If you are on HBase 1.+ you can use
Scan API:
setRowPrefixFilter(byte[] rowPrefix)
-Vlad
On Wed, Aug 24, 2016 at 5:28 AM, Ted Yu wrote:
> Please use the following API to set start row before calling
> hTable.getScanner(scan):
>
> public Scan setStartRow(byte [] startRow) {
>
> On Wed, Aug 24, 2016 at 5:08 AM, Manjeet Singh >
> wrote:
>
> > Hi All,
> >
> > I have below code where I have row key like 9865327845_#RandomChar
> > I want to perform prefix scan I tryed with ResultScanner which has
> > performance impact
> > I have seen in some articles people saying about Get and setFilter but
> its
> > not working
> > can anyone suggest me better way, below is my code
> >
> > public static HashSet getResultByPreFixFilterScan(String rowkeys){
> > Scan scan = new Scan();
> > PrefixFilter prefixFilter = new PrefixFilter(rowkeys.getBytes());
> > scan.setFilter(prefixFilter);
> > ResultScanner resultScanner = null;
> > try {
> > resultScanner = hTable.getScanner(scan);
> > } catch (IOException e) {
> > // TODO Auto-generated catch block
> > e.printStackTrace();
> > }
> >
> > HashSet rowKeySet=new HashSet();
> > //Result result = table.get(g);
> > for (Result results : resultScanner) {
> > for(KeyValue kv : results.raw()){
> > rowKeySet.add(new String(kv.getRow()));
> >
> > }
> > }
> > return rowKeySet;
> > }
> >
> >
> >
> >
> >
> > can we perform prefix by
> > Filter filter = new QualifierFilter(CompareFilter.CompareOp.EQUAL, new
> > BinaryComparator(Bytes.toBytes(rowkeys)));
> >
> > Thanks
> > Manjeet
> >
> > --
> > luv all
> >
>
Re: Multiple region servers on the same host
We used multiple regionservers on the same host for a long time. Our use case was a little different. We had a table (1 table on a cluster) that was 99% reads (random gets) and 1% writes. The table was tall and skinny and we needed really low latency gets. To keep everything in the block cache and to minimize GC time we had 5 regionservers per machine instead of one RS with a huge heap. This worked really well for us, deployment was a bit of a pain as a lot of the start / stop scripts wont work out of the box (or at least didn't at the time). Once bucket cache came around we just reverted back to one regionserver per machine as it was easier to handle operationally. But other than the operational pain, it seemed to work fine for us. On Wed, Aug 24, 2016 at 2:09 AM, Ted Yu wrote: > One downside is that when the machine crashes, you would lose more than one > region server. > > You may need to subclass RSGroupBasedLoadBalancer so that balancing > decision fits your requirement. > > Cheers > > On Tue, Aug 23, 2016 at 4:53 PM, GuangYang wrote: > > > Hello,We are recently exploring running multiple region servers on the > > same host, some of the potential benefits:1. smaller region server > > instance, thus potential less contention for better performance?2. We are > > running region server groups, thus we can run region server groups with > > different workloads on the same group of hardware. > > We plan to go with cgroups to isolate region servers on the same host, > > mainly because we have had good experience using cgroups within other > > hadoop projects. > > Has anyone played around with running multiple RS on the same host and > > would like to share the experience? > > Thanks,Guang >
Re: How to Speed up Prefix scan on column qualifier
I am using 1.2.1
I have tried these but actually ResultScanner took long time
is their any way to use Get with filter?
HBase already exposed setFilter method on Get class but its not working
On Wed, Aug 24, 2016 at 10:56 PM, Vladimir Rodionov
wrote:
> If you are on HBase 1.+ you can use
>
> Scan API:
>
> setRowPrefixFilter(byte[] rowPrefix)
>
>
> -Vlad
>
> On Wed, Aug 24, 2016 at 5:28 AM, Ted Yu wrote:
>
> > Please use the following API to set start row before calling
> > hTable.getScanner(scan):
> >
> > public Scan setStartRow(byte [] startRow) {
> >
> > On Wed, Aug 24, 2016 at 5:08 AM, Manjeet Singh <
> manjeet.chand...@gmail.com
> > >
> > wrote:
> >
> > > Hi All,
> > >
> > > I have below code where I have row key like 9865327845_#RandomChar
> > > I want to perform prefix scan I tryed with ResultScanner which has
> > > performance impact
> > > I have seen in some articles people saying about Get and setFilter but
> > its
> > > not working
> > > can anyone suggest me better way, below is my code
> > >
> > > public static HashSet getResultByPreFixFilterScan(String rowkeys){
> > > Scan scan = new Scan();
> > > PrefixFilter prefixFilter = new PrefixFilter(rowkeys.getBytes());
> > > scan.setFilter(prefixFilter);
> > > ResultScanner resultScanner = null;
> > > try {
> > > resultScanner = hTable.getScanner(scan);
> > > } catch (IOException e) {
> > > // TODO Auto-generated catch block
> > > e.printStackTrace();
> > > }
> > >
> > > HashSet rowKeySet=new HashSet();
> > > //Result result = table.get(g);
> > > for (Result results : resultScanner) {
> > > for(KeyValue kv : results.raw()){
> > > rowKeySet.add(new String(kv.getRow()));
> > >
> > > }
> > > }
> > > return rowKeySet;
> > > }
> > >
> > >
> > >
> > >
> > >
> > > can we perform prefix by
> > > Filter filter = new QualifierFilter(CompareFilter.CompareOp.EQUAL,
> new
> > > BinaryComparator(Bytes.toBytes(rowkeys)));
> > >
> > > Thanks
> > > Manjeet
> > >
> > > --
> > > luv all
> > >
> >
>
--
luv all
Re: How to Speed up Prefix scan on column qualifier
Get is used to retrieve single row.
If Get serves your need, you don't need PrefixFilter.
On Wed, Aug 24, 2016 at 11:58 AM, Manjeet Singh
wrote:
> I am using 1.2.1
>
> I have tried these but actually ResultScanner took long time
> is their any way to use Get with filter?
> HBase already exposed setFilter method on Get class but its not working
>
> On Wed, Aug 24, 2016 at 10:56 PM, Vladimir Rodionov <
> vladrodio...@gmail.com>
> wrote:
>
> > If you are on HBase 1.+ you can use
> >
> > Scan API:
> >
> > setRowPrefixFilter(byte[] rowPrefix)
> >
> >
> > -Vlad
> >
> > On Wed, Aug 24, 2016 at 5:28 AM, Ted Yu wrote:
> >
> > > Please use the following API to set start row before calling
> > > hTable.getScanner(scan):
> > >
> > > public Scan setStartRow(byte [] startRow) {
> > >
> > > On Wed, Aug 24, 2016 at 5:08 AM, Manjeet Singh <
> > manjeet.chand...@gmail.com
> > > >
> > > wrote:
> > >
> > > > Hi All,
> > > >
> > > > I have below code where I have row key like 9865327845_#RandomChar
> > > > I want to perform prefix scan I tryed with ResultScanner which has
> > > > performance impact
> > > > I have seen in some articles people saying about Get and setFilter
> but
> > > its
> > > > not working
> > > > can anyone suggest me better way, below is my code
> > > >
> > > > public static HashSet getResultByPreFixFilterScan(String rowkeys){
> > > > Scan scan = new Scan();
> > > > PrefixFilter prefixFilter = new PrefixFilter(rowkeys.getBytes());
> > > > scan.setFilter(prefixFilter);
> > > > ResultScanner resultScanner = null;
> > > > try {
> > > > resultScanner = hTable.getScanner(scan);
> > > > } catch (IOException e) {
> > > > // TODO Auto-generated catch block
> > > > e.printStackTrace();
> > > > }
> > > >
> > > > HashSet rowKeySet=new HashSet();
> > > > //Result result = table.get(g);
> > > > for (Result results : resultScanner) {
> > > > for(KeyValue kv : results.raw()){
> > > > rowKeySet.add(new String(kv.getRow()));
> > > >
> > > > }
> > > > }
> > > > return rowKeySet;
> > > > }
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > can we perform prefix by
> > > > Filter filter = new QualifierFilter(CompareFilter.CompareOp.EQUAL,
> > new
> > > > BinaryComparator(Bytes.toBytes(rowkeys)));
> > > >
> > > > Thanks
> > > > Manjeet
> > > >
> > > > --
> > > > luv all
> > > >
> > >
> >
>
>
>
> --
> luv all
>
How to get Last 1000 records from 1 millions records
Hi all Hbase didnt provide sorting on column but rowkey store in sorted form like small value first and greater value last example 1 2 3 4 5 6 7 and so on Assume I have 1 Miilions record but i want to look last 1000 records only Is their any way to do this? I don't want to perform any calculation on client side so may be any filter can help on it? Thanks Manjeet -- luv all
Re: How to Speed up Prefix scan on column qualifier
Get also support List object
On Thu, Aug 25, 2016 at 12:32 AM, Ted Yu wrote:
> Get is used to retrieve single row.
>
> If Get serves your need, you don't need PrefixFilter.
>
> On Wed, Aug 24, 2016 at 11:58 AM, Manjeet Singh <
> manjeet.chand...@gmail.com>
> wrote:
>
> > I am using 1.2.1
> >
> > I have tried these but actually ResultScanner took long time
> > is their any way to use Get with filter?
> > HBase already exposed setFilter method on Get class but its not working
> >
> > On Wed, Aug 24, 2016 at 10:56 PM, Vladimir Rodionov <
> > vladrodio...@gmail.com>
> > wrote:
> >
> > > If you are on HBase 1.+ you can use
> > >
> > > Scan API:
> > >
> > > setRowPrefixFilter(byte[] rowPrefix)
> > >
> > >
> > > -Vlad
> > >
> > > On Wed, Aug 24, 2016 at 5:28 AM, Ted Yu wrote:
> > >
> > > > Please use the following API to set start row before calling
> > > > hTable.getScanner(scan):
> > > >
> > > > public Scan setStartRow(byte [] startRow) {
> > > >
> > > > On Wed, Aug 24, 2016 at 5:08 AM, Manjeet Singh <
> > > manjeet.chand...@gmail.com
> > > > >
> > > > wrote:
> > > >
> > > > > Hi All,
> > > > >
> > > > > I have below code where I have row key like 9865327845_#RandomChar
> > > > > I want to perform prefix scan I tryed with ResultScanner which has
> > > > > performance impact
> > > > > I have seen in some articles people saying about Get and setFilter
> > but
> > > > its
> > > > > not working
> > > > > can anyone suggest me better way, below is my code
> > > > >
> > > > > public static HashSet getResultByPreFixFilterScan(String
> rowkeys){
> > > > > Scan scan = new Scan();
> > > > > PrefixFilter prefixFilter = new PrefixFilter(rowkeys.getBytes());
> > > > > scan.setFilter(prefixFilter);
> > > > > ResultScanner resultScanner = null;
> > > > > try {
> > > > > resultScanner = hTable.getScanner(scan);
> > > > > } catch (IOException e) {
> > > > > // TODO Auto-generated catch block
> > > > > e.printStackTrace();
> > > > > }
> > > > >
> > > > > HashSet rowKeySet=new HashSet();
> > > > > //Result result = table.get(g);
> > > > > for (Result results : resultScanner) {
> > > > > for(KeyValue kv : results.raw()){
> > > > > rowKeySet.add(new String(kv.getRow()));
> > > > >
> > > > > }
> > > > > }
> > > > > return rowKeySet;
> > > > > }
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > can we perform prefix by
> > > > > Filter filter = new QualifierFilter(CompareFilter.CompareOp.EQUAL,
> > > new
> > > > > BinaryComparator(Bytes.toBytes(rowkeys)));
> > > > >
> > > > > Thanks
> > > > > Manjeet
> > > > >
> > > > > --
> > > > > luv all
> > > > >
> > > >
> > >
> >
> >
> >
> > --
> > luv all
> >
>
--
luv all
Re: hbase replication : ERROR: Connection refused
Hello Ted, Great! thanks for keeping us posted. esteban. -- Cloudera, Inc. On Tue, Aug 23, 2016 at 5:42 PM, Ted wrote: > thanks, that helped. > > It showed it was doing a subsequent call via 127.0.0.1 so I double checked > all my configs to make sure I used the hostname/dns entries then it all > worked. > > thanks. > > > > On Tue, Aug 23, 2016 at 2:11 PM, Esteban Gutierrez > wrote: > > > Hello Ted, > > > > the first 2 commands interact with the HBase Master and the third command > > needs to get the splits from Meta, probably the exception is coming from > > there but its can you retry the commands but this time launching the > hbase > > shell with the -d flag? e.g. "hbase shell -d" that should give us a > better > > idea where that connection refused is coming from. > > > > cheers, > > esteban. > > > > -- > > Cloudera, Inc. > > > > > > On Tue, Aug 23, 2016 at 1:46 PM, Ted wrote: > > > > > Hi I'm running hbase 1.2.1 and I'm getting an error trying to setup > > > replication. > > > > > > I have 2 hbase systems running fine, > > > I can connect from both to each other via ssh and on all ports as > there's > > > no firewall (this is just a test system). > > > I can connect from the source to the destination ZK on port 2181 > > > > > > When I try to enable replication though I get "ERROR: Connection > refused" > > > with no other helpful information anywhere. > > > > > > --- > > > hbase(main):002:0> create 'test', 'cf' > > > 0 row(s) in 2.5390 seconds > > > > > > => Hbase::Table - test > > > hbase(main):003:0> add_peer 'vm2', "vm2:2181:/hbase" > > > 0 row(s) in 0.1830 seconds > > > > > > hbase(main):004:0> enable_table_replication 'test' > > > > > > ERROR: Connection refused > > > > > > Here is some help for this command: > > > Enable a table's replication switch. > > > > > > Examples: > > > > > > hbase> enable_table_replication 'table_name' > > > > > > > > > hbase(main):005:0> > > > --- > > > > > > There's no errors on the source logs, no log entries written at all > > during > > > the enable call. > > > On the destination logs there are also no errors. > > > If I do a "zk_dump" on the destination, I can see the source is > actually > > > connected. > > > > > > No replication is taking place, and other than that "error: connection > > > refused", I see no error messages. > > > > > > Anyone with any ideas on what and where it's trying to connect to? and > > why > > > it's being refused? > > > > > > -- > > > Ted. > > > > > > > > > -- > Ted. >
Re: How to get Last 1000 records from 1 millions records
The following API should help in your case:
public Scan setReversed(boolean reversed) {
Cheers
On Wed, Aug 24, 2016 at 12:05 PM, Manjeet Singh
wrote:
> Hi all
>
> Hbase didnt provide sorting on column but rowkey store in sorted form
> like small value first and greater value last
>
> example
> 1
> 2
> 3
> 4
> 5
> 6
> 7
> and so on
>
> Assume I have 1 Miilions record but i want to look last 1000 records only
> Is their any way to do this? I don't want to perform any calculation on
> client side so may be any filter can help on it?
>
> Thanks
> Manjeet
>
> --
> luv all
>
Re: How to get Last 1000 records from 1 millions records
As long as new rows are added to the latest region that "might" work. But
if the table is using hashed keys or rows are added randomly to the table
then retrieving the last million will be trickier and you will have to scan
based on timestamp (if not modified) and then filter one more time.
esteban.
--
Cloudera, Inc.
On Wed, Aug 24, 2016 at 12:31 PM, Ted Yu wrote:
> The following API should help in your case:
>
> public Scan setReversed(boolean reversed) {
>
> Cheers
>
> On Wed, Aug 24, 2016 at 12:05 PM, Manjeet Singh <
> manjeet.chand...@gmail.com>
> wrote:
>
> > Hi all
> >
> > Hbase didnt provide sorting on column but rowkey store in sorted form
> > like small value first and greater value last
> >
> > example
> > 1
> > 2
> > 3
> > 4
> > 5
> > 6
> > 7
> > and so on
> >
> > Assume I have 1 Miilions record but i want to look last 1000 records only
> > Is their any way to do this? I don't want to perform any calculation on
> > client side so may be any filter can help on it?
> >
> > Thanks
> > Manjeet
> >
> > --
> > luv all
> >
>
Re: How to get Last 1000 records from 1 millions records
Manjeet didn't mention hashing.
Nor did the example show hashed keys.
Cheers
On Wed, Aug 24, 2016 at 12:36 PM, Esteban Gutierrez
wrote:
> As long as new rows are added to the latest region that "might" work. But
> if the table is using hashed keys or rows are added randomly to the table
> then retrieving the last million will be trickier and you will have to scan
> based on timestamp (if not modified) and then filter one more time.
>
> esteban.
>
>
> --
> Cloudera, Inc.
>
>
> On Wed, Aug 24, 2016 at 12:31 PM, Ted Yu wrote:
>
> > The following API should help in your case:
> >
> > public Scan setReversed(boolean reversed) {
> >
> > Cheers
> >
> > On Wed, Aug 24, 2016 at 12:05 PM, Manjeet Singh <
> > manjeet.chand...@gmail.com>
> > wrote:
> >
> > > Hi all
> > >
> > > Hbase didnt provide sorting on column but rowkey store in sorted form
> > > like small value first and greater value last
> > >
> > > example
> > > 1
> > > 2
> > > 3
> > > 4
> > > 5
> > > 6
> > > 7
> > > and so on
> > >
> > > Assume I have 1 Miilions record but i want to look last 1000 records
> only
> > > Is their any way to do this? I don't want to perform any calculation on
> > > client side so may be any filter can help on it?
> > >
> > > Thanks
> > > Manjeet
> > >
> > > --
> > > luv all
> > >
> >
>
Re: How to Speed up Prefix scan on column qualifier
I was talking about Get object.
You were talking about:
public Result[] get(List gets) throws IOException {
Note: in the above case, it is easy to apply prefix filter over the List of
Get's on the client side.
On Wed, Aug 24, 2016 at 12:05 PM, Manjeet Singh
wrote:
> Get also support List object
>
> On Thu, Aug 25, 2016 at 12:32 AM, Ted Yu wrote:
>
> > Get is used to retrieve single row.
> >
> > If Get serves your need, you don't need PrefixFilter.
> >
> > On Wed, Aug 24, 2016 at 11:58 AM, Manjeet Singh <
> > manjeet.chand...@gmail.com>
> > wrote:
> >
> > > I am using 1.2.1
> > >
> > > I have tried these but actually ResultScanner took long time
> > > is their any way to use Get with filter?
> > > HBase already exposed setFilter method on Get class but its not working
> > >
> > > On Wed, Aug 24, 2016 at 10:56 PM, Vladimir Rodionov <
> > > vladrodio...@gmail.com>
> > > wrote:
> > >
> > > > If you are on HBase 1.+ you can use
> > > >
> > > > Scan API:
> > > >
> > > > setRowPrefixFilter(byte[] rowPrefix)
> > > >
> > > >
> > > > -Vlad
> > > >
> > > > On Wed, Aug 24, 2016 at 5:28 AM, Ted Yu wrote:
> > > >
> > > > > Please use the following API to set start row before calling
> > > > > hTable.getScanner(scan):
> > > > >
> > > > > public Scan setStartRow(byte [] startRow) {
> > > > >
> > > > > On Wed, Aug 24, 2016 at 5:08 AM, Manjeet Singh <
> > > > manjeet.chand...@gmail.com
> > > > > >
> > > > > wrote:
> > > > >
> > > > > > Hi All,
> > > > > >
> > > > > > I have below code where I have row key like
> 9865327845_#RandomChar
> > > > > > I want to perform prefix scan I tryed with ResultScanner which
> has
> > > > > > performance impact
> > > > > > I have seen in some articles people saying about Get and
> setFilter
> > > but
> > > > > its
> > > > > > not working
> > > > > > can anyone suggest me better way, below is my code
> > > > > >
> > > > > > public static HashSet getResultByPreFixFilterScan(String
> > rowkeys){
> > > > > > Scan scan = new Scan();
> > > > > > PrefixFilter prefixFilter = new PrefixFilter(rowkeys.getBytes(
> ));
> > > > > > scan.setFilter(prefixFilter);
> > > > > > ResultScanner resultScanner = null;
> > > > > > try {
> > > > > > resultScanner = hTable.getScanner(scan);
> > > > > > } catch (IOException e) {
> > > > > > // TODO Auto-generated catch block
> > > > > > e.printStackTrace();
> > > > > > }
> > > > > >
> > > > > > HashSet rowKeySet=new HashSet();
> > > > > > //Result result = table.get(g);
> > > > > > for (Result results : resultScanner) {
> > > > > > for(KeyValue kv : results.raw()){
> > > > > > rowKeySet.add(new String(kv.getRow()));
> > > > > >
> > > > > > }
> > > > > > }
> > > > > > return rowKeySet;
> > > > > > }
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > can we perform prefix by
> > > > > > Filter filter = new QualifierFilter(CompareFilter.
> CompareOp.EQUAL,
> > > > new
> > > > > > BinaryComparator(Bytes.toBytes(rowkeys)));
> > > > > >
> > > > > > Thanks
> > > > > > Manjeet
> > > > > >
> > > > > > --
> > > > > > luv all
> > > > > >
> > > > >
> > > >
> > >
> > >
> > >
> > > --
> > > luv all
> > >
> >
>
>
>
> --
> luv all
>
Re: How to get Last 1000 records from 1 millions records
Hey Manjeet, How much data are you actually trying to get the last 1000 records for? If you're dealing at the scale of only millions of rows, HBase may not be the best choice for this type of problem. On Wed, Aug 24, 2016 at 12:05 PM, Manjeet Singh wrote: > Hi all > > Hbase didnt provide sorting on column but rowkey store in sorted form > like small value first and greater value last > > example > 1 > 2 > 3 > 4 > 5 > 6 > 7 > and so on > > Assume I have 1 Miilions record but i want to look last 1000 records only > Is their any way to do this? I don't want to perform any calculation on > client side so may be any filter can help on it? > > Thanks > Manjeet > > -- > luv all > -- -Dima
