Note also that the createConnection part is somewhat expensive (creates a new
thread pool for use with Puts, also does a ZK lookup, etc).If possible create
the connection ahead of time and only get/close an HTable per request/thread.
-- Lars
From: Serega Sheypak <serega.shey...@gmail.com>
To: user <user@hbase.apache.org>
Sent: Friday, December 12, 2014 11:45 AM
Subject: Re: HConnectionManager leaks with zookeeper conection oo many
connections from /my.tomcat.server.com - max is 60
i have 10K doPost/doGet requests per second.
Servlet is NOT single-threaded. each doPost/doGet
invokes these lines (encapsulated in DAO):
16 HConnection connection =
HConnectionManager.createConnection(config);
17 HTableInterface table =
connection.getTable(TableName.valueOf("table1"));
and
24 } finally {
25 table.close();
26 connection.close();
27 }
I assumed that this static construction
16 HConnection connection =
HConnectionManager.createConnection(config);
correctly handles multi-threaded access somewhere deep inside.
Right now I don't understand what do I do wrong.
Try to wrap each your request in Runnable to emulate multi-threaded
pressure on ZK. Your code is linear and mine is not, it's concurrent.
Thanks....
2014-12-12 22:28 GMT+03:00 Stack <st...@duboce.net>:
>
> I cannot reproduce. I stood up a cdh5.2 server and then copy/pasted your
> code adding in a put for each cycle. I ran loop 1000 times and no
> complaint from zk.
>
> Tell me more (Is servlet doing single-threaded model? A single
> Configuration is being used or new ones are being created per servlet
> invocation?
>
> Below is code and output.
>
> (For better perf, cache the connection)
> St.Ack
>
>
> 1 package org.apache.hadoop.hbase;
> 2
> 3 import java.io.IOException;
> 4
> 5 import org.apache.hadoop.conf.Configuration;
> 6 import org.apache.hadoop.hbase.client.HConnection;
> 7 import org.apache.hadoop.hbase.client.HConnectionManager;
> 8 import org.apache.hadoop.hbase.client.HTableInterface;
> 9 import org.apache.hadoop.hbase.client.Put;
> 10 import org.apache.hadoop.hbase.util.Bytes;
> 11
> 12 public class TestConnnection {
> 13 public static void main(String[] args) throws IOException {
> 14 Configuration config = HBaseConfiguration.create();
> 15 for (int i = 0; i < 1000; i++) {
> 16 HConnection connection =
> HConnectionManager.createConnection(config);
> 17 HTableInterface table =
> connection.getTable(TableName.valueOf("table1"));
> 18 byte [] cf = Bytes.toBytes("t");
> 19 try {
> 20 byte [] bytes = Bytes.toBytes(i);
> 21 Put p = new Put(bytes);
> 22 p.add(cf, cf, bytes);
> 23 table.put(p);
> 24 } finally {
> 25 table.close();
> 26 connection.close();
> 27 }
> 28 System.out.println("i=" + i);
> 29 }
> 30 }
> 31 }
>
>
> ....
> 2014-12-12 11:26:10,397 INFO [main] zookeeper.RecoverableZooKeeper:
> Process identifier=hconnection-0x70dfa475 connecting to ZooKeeper
> ensemble=localhost:2181
> 2014-12-12 11:26:10,397 INFO [main] zookeeper.ZooKeeper: Initiating client
> connection, connectString=localhost:2181 sessionTimeout=90000
> watcher=hconnection-0x70dfa475, quorum=localhost:2181, baseZNode=/hbase
> 2014-12-12 11:26:10,398 INFO [main-SendThread(localhost:2181)]
> zookeeper.ClientCnxn: Opening socket connection to server localhost/
> 127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown
> error)
> 2014-12-12 11:26:10,398 INFO [main-SendThread(localhost:2181)]
> zookeeper.ClientCnxn: Socket connection established to localhost/
> 127.0.0.1:2181, initiating session
> 2014-12-12 11:26:10,401 INFO [main-SendThread(localhost:2181)]
> zookeeper.ClientCnxn: Session establishment complete on server localhost/
> 127.0.0.1:2181, sessionid = 0x14a3fe0664b083a, negotiated timeout = 40000
> 2014-12-12 11:26:10,405 DEBUG [main] client.ClientSmallScanner: Finished
> with small scan at {ENCODED => 1588230740, NAME => 'hbase:meta,,1',
> STARTKEY => '', ENDKEY => ''}
> 2014-12-12 11:26:10,406 INFO [main]
> client.HConnectionManager$HConnectionImplementation: Closing zookeeper
> sessionid=0x14a3fe0664b083a
> 2014-12-12 11:26:10,407 INFO [main] zookeeper.ZooKeeper: Session:
> 0x14a3fe0664b083a closed
> 2014-12-12 11:26:10,407 INFO [main-EventThread] zookeeper.ClientCnxn:
> EventThread shut down
> i=997
> 2014-12-12 11:26:10,511 INFO [main] zookeeper.RecoverableZooKeeper:
> Process identifier=hconnection-0x22a7106 connecting to ZooKeeper
> ensemble=localhost:2181
> 2014-12-12 11:26:10,511 INFO [main] zookeeper.ZooKeeper: Initiating client
> connection, connectString=localhost:2181 sessionTimeout=90000
> watcher=hconnection-0x22a7106, quorum=localhost:2181, baseZNode=/hbase
> 2014-12-12 11:26:10,512 INFO [main-SendThread(localhost:2181)]
> zookeeper.ClientCnxn: Opening socket connection to server
> localhost/0:0:0:0:0:0:0:1:2181. Will not attempt to authenticate using SASL
> (unknown error)
> 2014-12-12 11:26:10,512 INFO [main-SendThread(localhost:2181)]
> zookeeper.ClientCnxn: Socket connection established to
> localhost/0:0:0:0:0:0:0:1:2181, initiating session
> 2014-12-12 11:26:10,515 INFO [main-SendThread(localhost:2181)]
> zookeeper.ClientCnxn: Session establishment complete on server
> localhost/0:0:0:0:0:0:0:1:2181, sessionid = 0x14a3fe0664b083b, negotiated
> timeout = 40000
> 2014-12-12 11:26:10,519 DEBUG [main] client.ClientSmallScanner: Finished
> with small scan at {ENCODED => 1588230740, NAME => 'hbase:meta,,1',
> STARTKEY => '', ENDKEY => ''}
> 2014-12-12 11:26:10,521 INFO [main]
> client.HConnectionManager$HConnectionImplementation: Closing zookeeper
> sessionid=0x14a3fe0664b083b
> 2014-12-12 11:26:10,521 INFO [main] zookeeper.ZooKeeper: Session:
> 0x14a3fe0664b083b closed
> 2014-12-12 11:26:10,521 INFO [main-EventThread] zookeeper.ClientCnxn:
> EventThread shut down
> i=998
> 2014-12-12 11:26:10,627 INFO [main] zookeeper.RecoverableZooKeeper:
> Process identifier=hconnection-0x3822f407 connecting to ZooKeeper
> ensemble=localhost:2181
> 2014-12-12 11:26:10,627 INFO [main] zookeeper.ZooKeeper: Initiating client
> connection, connectString=localhost:2181 sessionTimeout=90000
> watcher=hconnection-0x3822f407, quorum=localhost:2181, baseZNode=/hbase
> 2014-12-12 11:26:10,628 INFO [main-SendThread(localhost:2181)]
> zookeeper.ClientCnxn: Opening socket connection to server localhost/
> 127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown
> error)
> 2014-12-12 11:26:10,629 INFO [main-SendThread(localhost:2181)]
> zookeeper.ClientCnxn: Socket connection established to localhost/
> 127.0.0.1:2181, initiating session
> 2014-12-12 11:26:10,631 INFO [main-SendThread(localhost:2181)]
> zookeeper.ClientCnxn: Session establishment complete on server localhost/
> 127.0.0.1:2181, sessionid = 0x14a3fe0664b083c, negotiated timeout = 40000
> 2014-12-12 11:26:10,637 DEBUG [main] client.ClientSmallScanner: Finished
> with small scan at {ENCODED => 1588230740, NAME => 'hbase:meta,,1',
> STARTKEY => '', ENDKEY => ''}
> 2014-12-12 11:26:10,638 INFO [main]
> client.HConnectionManager$HConnectionImplementation: Closing zookeeper
> sessionid=0x14a3fe0664b083c
> 2014-12-12 11:26:10,639 INFO [main] zookeeper.ZooKeeper: Session:
> 0x14a3fe0664b083c closed
> 2014-12-12 11:26:10,639 INFO [main-EventThread] zookeeper.ClientCnxn:
> EventThread shut down
> i=999
>
>
>
>
> On Fri, Dec 12, 2014 at 10:22 AM, Serega Sheypak <serega.shey...@gmail.com
> >
> wrote:
>
> > Hi, I'm using CDH 5.2, 0.98
> > I don't know how to use it correctly. I've just used this sample:
> >
> >
> https://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HConnectionManager.html
> >
> > HConnection connection = HConnectionManager.createConnection(config);
> > HTableInterface table =
> connection.getTable(TableName.valueOf("table1"));
> > try {
> > // Use the table as needed, for a single operation and a single thread
> > } finally {
> > table.close();
> > connection.close();
> > }
> >
> >
> > Functional testing OK, performance fails :((((
> >
> >
> >
> > 2014-12-12 19:32 GMT+03:00 Stack <st...@duboce.net>:
> > >
> > > Does zk count go up on each request to the servlet? Which version of
> > hbase
> > > so can try on this end? Do you have some client-side log? Better if
> you
> > > cache the connection rather than make it each time since setup is
> costly
> > > but lets fix first problem first.
> > > St.Ack
> > >
> > > On Fri, Dec 12, 2014 at 2:47 AM, Serega Sheypak <
> > serega.shey...@gmail.com>
> > > wrote:
> > >
> > > > Hi, I'm using HConnectionManager from java servlet
> > > > Looks like it's leaking, all my zookeepers complains that there is
> too
> > > many
> > > > connections from servlet hosts.
> > > > Typical line from lZK log:
> > > >
> > > > oo many connections from /my.tomcat.server.com - max is 60
> > > >
> > > >
> > > > Here is code sample
> > > >
> > > > public class BaseConnection {
> > > >
> > > > private static final Logger LOG =
> > > > LoggerFactory.getLogger(BaseConnection.class);
> > > >
> > > > protected void close(HConnection connection){
> > > > try{
> > > > if(connection == null){
> > > > return;
> > > > }
> > > > connection.close();
> > > > }
> > > > catch (Exception e){
> > > > LOG.warn("Error while closing HConnection", e);
> > > > }
> > > > }
> > > >
> > > > protected void close(HTableInterface hTable){
> > > > try{
> > > > if(hTable == null){
> > > > return;
> > > > }
> > > > hTable.close();
> > > > }
> > > > catch (Exception e){
> > > > LOG.warn("Error while closing HTable", e);
> > > > }
> > > > }
> > > > }
> > > >
> > > > sample PUT code from subclass:
> > > >
> > > > public void put(List<MyBean> entries){
> > > > HConnection hConnection = null;
> > > > HTableInterface hTable = null;
> > > > try {
> > > > List<Put> puts = new ArrayList<Put>(entries.size());
> > > > for(MyBean myBean : entries){
> > > > puts.add(new MyBeanSerDe().createPut(myBean));
> > > > }
> > > > hConnection =
> > HConnectionManager.createConnection(configuration);
> > > > hTable = hConnection.getTable(NAME_B);
> > > > hTable.put(puts);
> > > >
> > > > }catch (Exception e){
> > > > LOG.error("Error while doing bulk put", e);
> > > > }finally{
> > > > close(hTable);
> > > > close(hConnection);
> > > > }
> > > > }
> > > >
> > >
> >
>
