Hi Ming,
HConnection connection = HConnectionManager.createConnection(conf);
HTableInterface table = connection.getTable("mytable");
table.get(...); / table.put(...);
Is the correct way to use. However
HConnectionManager.createConnection(conf) gives you a "shared" HConnection
which you can reuse across multiple threads that get their own
conn.getTable() and do their puts/gets.
Thanks,
Bharath
On Mon, Nov 24, 2014 at 2:03 PM, Liu, Ming (HPIT-GADSC) <[email protected]>
wrote:
> Hello,
>
> I am using HBase 0.98.5. In example hbase client programs, some use
> createConnection() and some use HTable() directly, I found they behave
> different, I wrote two simple tests program using these two different
> methods, each program will start two threads and do simple put. and I
> found:
> One program will start only 1 zookeeper sessions shared in two threads
> while another will start 2 zookeeper sessions. So I don't know why the
> program using createConnection will do more zookeeper requests than simply
> use HTable. Is it possible to use createConnection in two threads but share
> the same zookeeper session?
>
> Here is details:
> Demo1 will make two zookeeper sessions, seems two HBase connections; but
> Demo2 will only make one zookeeper session. My real program is using
> createConnection in multiple threads as in demo1, since I have a very small
> zookeeper , it only allows 60 concurrent sessions, so my program always
> fail when there are hundreds of threads started. But I saw if using HTable
> directly, it will only consume 1 zookeeper session. But it will change a
> lot in my current program, so I wish there is a way to use createConnection
> and behave same as using HTable, is it possible?
>
> Source code:
>
> Demo1.java
> class ClientThread extends Thread
> {
> public static Configuration configuration;
> static {
> configuration = HBaseConfiguration.create();
> }
> public void run()
> {
> try {
> System.out.println("start insert data ......");
> HConnection
> con=HConnectionManager.createConnection(configuration);
> HTable table = (HTable)con.getTable("hbase_table1");
> Put put = new Put("1".getBytes());
> put.add("c1".getBytes(), null, "baidu".getBytes());
> put.add("c2".getBytes(), null, "http://www.baidu.com1
> ".getBytes());
> try {
> table.put(put);
> } catch (IOException e) {
> e.printStackTrace();
> }
> System.out.println("end insert data ......");
> }
> catch (Exception e) {
> }
>
> }
> }
> public class demo1 {
>
> public static void main(String[] args) throws Exception {
> Thread t1=new ClientThread();
> Thread t2=new ClientThread();
> t1.start();
> t2.start();
> }
>
> }
>
>
> Demo2.java
> class ClientThread1 extends Thread
> {
> public static Configuration configuration;
> static {
> configuration = HBaseConfiguration.create();
> }
> public void run()
> {
> System.out.println("start insert data ......");
> try {
> HTableInterface table = new HTable(configuration,
> "hbase_table1");
> Put put = new Put("1".getBytes());
> put.add("c1".getBytes(), null, "baidu".getBytes());
> put.add("c2".getBytes(), null, "
> http://www.baidu.com1".getBytes());
> table.put(put);
> } catch (Exception e) {
> e.printStackTrace();
> }
> System.out.println("end insert data ......");
>
> }
>
>
> }
> public class demo2 {
>
> public static void main(String[] args) throws Exception {
> Thread t1=new ClientThread1();
> Thread t2=new ClientThread1();
> t1.start();
> t2.start();
> }
> }
>
>
>
> This should be a very basic question, sorry, I really did some search but
> cannot find any good explaination. Any help will be very appreciated.
>
> Thanks,
> Ming
>
--
Bharath Vissapragada
<http://www.cloudera.com>
