Thread: [Postgres-xc-general] Where to connect to communicate pgxc with Application

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postgres-xc-general

[Postgres-xc-general] Where to connect to communicate pgxc with Application

From: Juned K. <jkh...@gm...> - 2014-03-14 12:11:36

Hi all,

I have just setup postgre-xc with four servers for testing.
with this four system from GTM server i am able to connect
to database and it selects one of coordinator,. it just works fine.

But now i want to integrate this with my application where application
is on separate server.

so in this case where to connect in pgxc ?

which IP and port i should set in my application to communicate with it?

>From some documentation i came to know i should connect to coordinator
but from other system i am not able connect to the database. i am getting
this

[postgres@localhost ~]$ psql -H 192.168.1.73 -U postgres -d dbname -p 20004
> psql: warning: extra command-line argument "192.168.1.73" ignored
> psql: could not connect to server: No such file or directory
>         Is the server running locally and accepting
>         connections on Unix domain socket "/tmp/.s.PGSQL.20004"?
>


But on this server seems socket port is open

> [root@localhost ~]# netstat -pan | grep postgre
> tcp        0      0 0.0.0.0:20004               0.0.0.0:*
> LISTEN      9454/postgres
> tcp        0      0 0.0.0.0:20008               0.0.0.0:*
> LISTEN      9522/postgres
> tcp        0      0 192.168.1.73:20008          192.168.1.73:33950
> ESTABLISHED 10025/postgres
> tcp        0      0 192.168.1.73:33950          192.168.1.73:20008
> ESTABLISHED 9459/postgres
> tcp        0      0 192.168.1.73:35014          192.168.1.73:20001
> ESTABLISHED 9522/postgres
> tcp        0      0 192.168.1.73:35006          192.168.1.73:20001
> ESTABLISHED 9454/postgres
> tcp        0      0 192.168.1.73:57794          192.168.1.43:20009
> ESTABLISHED 9459/postgres
> tcp        0      0 :::20004
> :::*                        LISTEN      9454/postgres
> tcp        0      0 :::20008
> :::*                        LISTEN      9522/postgres
> udp        0      0 ::1:60142
> ::1:60142                   ESTABLISHED 9522/postgres
> udp        0      0 ::1:59683
> ::1:59683                   ESTABLISHED 9454/postgres
> unix  2      [ ACC ]     STREAM     LISTENING     84606
> 9454/postgres       /tmp/.s.PGSQL.20004
> unix  2      [ ACC ]     STREAM     LISTENING     84641
> 9459/postgres       /tmp/.s.PGPOOL.20010
> unix  2      [ ACC ]     STREAM     LISTENING     85268
> 9522/postgres       /tmp/.s.PGSQL.20008
>



am i doing correct ?

Please suggest.

-- 
Thanks,
Juned Khan
iNextrix Technologies Pvt Ltd.
www.inextrix.com

Re: [Postgres-xc-general] Where to connect to communicate pgxc with Application

From: Koichi S. <koi...@gm...> - 2014-03-14 22:29:49

Application can connect to ANY coordinator (not datanode).   So most
likely is to assign different coordinator to different application
instance.   You can use usual -p and -h parameter for different
coordinator from your applications.

All the coordinator provides the same database view and any updating
transaction is propagated to all the node without conflict.

Regards;
---
Koichi Suzuki


2014-03-14 12:11 GMT+00:00 Juned Khan <jkh...@gm...>:
> Hi all,
>
> I have just setup postgre-xc with four servers for testing.
> with this four system from GTM server i am able to connect
> to database and it selects one of coordinator,. it just works fine.
>
> But now i want to integrate this with my application where application
> is on separate server.
>
> so in this case where to connect in pgxc ?
>
> which IP and port i should set in my application to communicate with it?
>
> From some documentation i came to know i should connect to coordinator
> but from other system i am not able connect to the database. i am getting
> this
>
>> [postgres@localhost ~]$ psql -H 192.168.1.73 -U postgres -d dbname -p
>> 20004
>> psql: warning: extra command-line argument "192.168.1.73" ignored
>> psql: could not connect to server: No such file or directory
>>         Is the server running locally and accepting
>>         connections on Unix domain socket "/tmp/.s.PGSQL.20004"?
>
>
>
> But on this server seems socket port is open
>>
>> [root@localhost ~]# netstat -pan | grep postgre
>> tcp        0      0 0.0.0.0:20004               0.0.0.0:*
>> LISTEN      9454/postgres
>> tcp        0      0 0.0.0.0:20008               0.0.0.0:*
>> LISTEN      9522/postgres
>> tcp        0      0 192.168.1.73:20008          192.168.1.73:33950
>> ESTABLISHED 10025/postgres
>> tcp        0      0 192.168.1.73:33950          192.168.1.73:20008
>> ESTABLISHED 9459/postgres
>> tcp        0      0 192.168.1.73:35014          192.168.1.73:20001
>> ESTABLISHED 9522/postgres
>> tcp        0      0 192.168.1.73:35006          192.168.1.73:20001
>> ESTABLISHED 9454/postgres
>> tcp        0      0 192.168.1.73:57794          192.168.1.43:20009
>> ESTABLISHED 9459/postgres
>> tcp        0      0 :::20004                    :::*
>> LISTEN      9454/postgres
>> tcp        0      0 :::20008                    :::*
>> LISTEN      9522/postgres
>> udp        0      0 ::1:60142                   ::1:60142
>> ESTABLISHED 9522/postgres
>> udp        0      0 ::1:59683                   ::1:59683
>> ESTABLISHED 9454/postgres
>> unix  2      [ ACC ]     STREAM     LISTENING     84606  9454/postgres
>> /tmp/.s.PGSQL.20004
>> unix  2      [ ACC ]     STREAM     LISTENING     84641  9459/postgres
>> /tmp/.s.PGPOOL.20010
>> unix  2      [ ACC ]     STREAM     LISTENING     85268  9522/postgres
>> /tmp/.s.PGSQL.20008
>
>
>
>
> am i doing correct ?
>
> Please suggest.
>
> --
> Thanks,
> Juned Khan
> iNextrix Technologies Pvt Ltd.
> www.inextrix.com
>
> ------------------------------------------------------------------------------
> Learn Graph Databases - Download FREE O'Reilly Book
> "Graph Databases" is the definitive new guide to graph databases and their
> applications. Written by three acclaimed leaders in the field,
> this first edition is now available. Download your free book today!
> http://p.sf.net/sfu/13534_NeoTech
> _______________________________________________
> Postgres-xc-general mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-general
>

Re: [Postgres-xc-general] 答复: Where to connect to communicate pgxc with Application

From: Juned K. <jkh...@gm...> - 2014-03-15 07:42:51

Hi koichi,zhangzl

Thanks for your suggestions.

So i have to connect my application to directly one of coordinator right.
I thought i have to connect my application to GTM from where my application
will use one of available coordinator.

In this case if i connect my application to connect specific coordinator
using port
then what will happen if that coordinator goes down ?

in the case of GTM when i execute simply Psql -dkoichi then it selects
available
coordinator automatically, this is not possible to setup with application?
if i am able to
connect my application to directly GTM and then it will select any of
available coordinator.

Please suggest.



On Sat, Mar 15, 2014 at 4:59 AM, 张仲良 <zh...@li...> wrote:

> Use h instead of H；
>
> Maybe you should check your pg_hba.conf file if you still cannot connect
> to it.
>
>
>
> *发件人:* Juned Khan [mailto:jkh...@gm...]
> *发送时间:* 2014年3月14日 20:11
> *收件人:* Postgres-XC mailing list
> *主题:* [Postgres-xc-general] Where to connect to communicate pgxc with
> Application
>
>
>
> Hi all,
>
> I have just setup postgre-xc with four servers for testing.
>
> with this four system from GTM server i am able to connect
>
> to database and it selects one of coordinator,. it just works fine.
>
> But now i want to integrate this with my application where application
>
> is on separate server.
>
> so in this case where to connect in pgxc ?
>
> which IP and port i should set in my application to communicate with it?
>
> From some documentation i came to know i should connect to coordinator
>
> but from other system i am not able connect to the database. i am getting
> this
>
>
>
> [postgres@localhost ~]$ psql -H 192.168.1.73 -U postgres -d dbname -p
> 20004
> psql: warning: extra command-line argument "192.168.1.73" ignored
> psql: could not connect to server: No such file or directory
>         Is the server running locally and accepting
>         connections on Unix domain socket "/tmp/.s.PGSQL.20004"?
>
>
>
>
>
> But on this server seems socket port is open
>
> [root@localhost ~]# netstat -pan | grep postgre
> tcp        0      0 0.0.0.0:20004               0.0.0.0:*
> LISTEN      9454/postgres
> tcp        0      0 0.0.0.0:20008               0.0.0.0:*
> LISTEN      9522/postgres
> tcp        0      0 192.168.1.73:20008          192.168.1.73:33950
> ESTABLISHED 10025/postgres
> tcp        0      0 192.168.1.73:33950          192.168.1.73:20008
> ESTABLISHED 9459/postgres
> tcp        0      0 192.168.1.73:35014          192.168.1.73:20001
> ESTABLISHED 9522/postgres
> tcp        0      0 192.168.1.73:35006          192.168.1.73:20001
> ESTABLISHED 9454/postgres
> tcp        0      0 192.168.1.73:57794          192.168.1.43:20009
> ESTABLISHED 9459/postgres
> tcp        0      0 :::20004
> :::*                        LISTEN      9454/postgres
> tcp        0      0 :::20008
> :::*                        LISTEN      9522/postgres
> udp        0      0 ::1:60142
> ::1:60142                   ESTABLISHED 9522/postgres
> udp        0      0 ::1:59683
> ::1:59683                   ESTABLISHED 9454/postgres
> unix  2      [ ACC ]     STREAM     LISTENING     84606
> 9454/postgres       /tmp/.s.PGSQL.20004
> unix  2      [ ACC ]     STREAM     LISTENING     84641
> 9459/postgres       /tmp/.s.PGPOOL.20010
> unix  2      [ ACC ]     STREAM     LISTENING     85268
> 9522/postgres       /tmp/.s.PGSQL.20008
>
>
>
> am i doing correct ?
>
> Please suggest.
>
>
>
> --
>
> Thanks,
> Juned Khan
> iNextrix Technologies Pvt Ltd.
> www.inextrix.com
>



-- 
Thanks,
Juned Khan
iNextrix Technologies Pvt Ltd.
www.inextrix.com

[Postgres-xc-general] 答复: Where to connect to communicate pgxc with Application

From: 张仲良 <zh...@li...> - 2014-03-14 23:30:02

Use h instead of H；

Maybe you should check your pg_hba.conf file if you still cannot connect to
it. 

 

发件人: Juned Khan [mailto:jkh...@gm...] 
发送时间: 2014年3月14日 20:11
收件人: Postgres-XC mailing list
主题: [Postgres-xc-general] Where to connect to communicate pgxc with
Application

 

Hi all,

I have just setup postgre-xc with four servers for testing.

with this four system from GTM server i am able to connect

to database and it selects one of coordinator,. it just works fine.

But now i want to integrate this with my application where application

is on separate server. 

so in this case where to connect in pgxc ?

which IP and port i should set in my application to communicate with it?

>From some documentation i came to know i should connect to coordinator

but from other system i am not able connect to the database. i am getting
this

 

[postgres@localhost ~]$ psql -H 192.168.1.73 -U postgres -d dbname -p 20004
psql: warning: extra command-line argument "192.168.1.73" ignored
psql: could not connect to server: No such file or directory
        Is the server running locally and accepting
        connections on Unix domain socket "/tmp/.s.PGSQL.20004"?

 

 

But on this server seems socket port is open

[root@localhost ~]# netstat -pan | grep postgre
tcp        0      0 0.0.0.0:20004               0.0.0.0:*
LISTEN      9454/postgres       
tcp        0      0 0.0.0.0:20008               0.0.0.0:*
LISTEN      9522/postgres       
tcp        0      0 192.168.1.73:20008          192.168.1.73:33950
ESTABLISHED 10025/postgres      
tcp        0      0 192.168.1.73:33950          192.168.1.73:20008
ESTABLISHED 9459/postgres       
tcp        0      0 192.168.1.73:35014          192.168.1.73:20001
ESTABLISHED 9522/postgres       
tcp        0      0 192.168.1.73:35006          192.168.1.73:20001
ESTABLISHED 9454/postgres       
tcp        0      0 192.168.1.73:57794          192.168.1.43:20009
ESTABLISHED 9459/postgres       
tcp        0      0 :::20004                    :::*
LISTEN      9454/postgres       
tcp        0      0 :::20008                    :::*
LISTEN      9522/postgres       
udp        0      0 ::1:60142                   ::1:60142
ESTABLISHED 9522/postgres       
udp        0      0 ::1:59683                   ::1:59683
ESTABLISHED 9454/postgres       
unix  2      [ ACC ]     STREAM     LISTENING     84606  9454/postgres
/tmp/.s.PGSQL.20004
unix  2      [ ACC ]     STREAM     LISTENING     84641  9459/postgres
/tmp/.s.PGPOOL.20010
unix  2      [ ACC ]     STREAM     LISTENING     85268  9522/postgres
/tmp/.s.PGSQL.20008





am i doing correct ?  

Please suggest.

 

-- 

Thanks,
Juned Khan
iNextrix Technologies Pvt Ltd.
 <http://www.inextrix.com/> www.inextrix.com

Re: [Postgres-xc-general] 答复: Where to connect to communicate pgxc with Application

From: Mason S. <ms...@tr...> - 2014-03-16 11:55:41

On Sat, Mar 15, 2014 at 3:42 AM, Juned Khan <jkh...@gm...> wrote:

> Hi koichi,zhangzl
>
> Thanks for your suggestions.
>
> So i have to connect my application to directly one of coordinator right.
> I thought i have to connect my application to GTM from where my application
> will use one of available coordinator.
>
> In this case if i connect my application to connect specific coordinator
> using port
> then what will happen if that coordinator goes down ?
>
> in the case of GTM when i execute simply Psql -dkoichi then it selects
> available
> coordinator automatically, this is not possible to setup with application?
> if i am able to
> connect my application to directly GTM and then it will select any of
> available coordinator.
>
> Please suggest.
>
>
>
That could possibly be an interesting extension to GTM... but then if GTM
goes down you application would still not know where to look for the
standby.

You could also try the approach outlined in a blog posting here,
essentially using DNS to load balance amongst multiple coordinators.

http://www.translattice.com/blog/Load_Balancing_Postgres-XC.shtml


-- 
Mason Sharp

TransLattice - http://www.translattice.com
Distributed and Clustered Database Solutions

Re: [Postgres-xc-general] 答复: Where to connect to communicate pgxc with Application

From: Koichi S. <koi...@gm...> - 2014-03-18 06:53:20

As Mason mentioned, yes automatic selection of a coordinator will help
for load balancing as well.

JDBC has some capability which selects one of the connection point
from url list but libpq does not.

Libpq/JDBC extension for load balancing (and to search for live
coordinator) will be a nice extension.
---
Koichi Suzuki


2014-03-16 20:55 GMT+09:00 Mason Sharp <ms...@tr...>:
>
>
>
> On Sat, Mar 15, 2014 at 3:42 AM, Juned Khan <jkh...@gm...> wrote:
>>
>> Hi koichi,zhangzl
>>
>> Thanks for your suggestions.
>>
>> So i have to connect my application to directly one of coordinator right.
>> I thought i have to connect my application to GTM from where my
>> application
>> will use one of available coordinator.
>>
>> In this case if i connect my application to connect specific coordinator
>> using port
>> then what will happen if that coordinator goes down ?
>>
>> in the case of GTM when i execute simply Psql -dkoichi then it selects
>> available
>> coordinator automatically, this is not possible to setup with application?
>> if i am able to
>> connect my application to directly GTM and then it will select any of
>> available coordinator.
>>
>> Please suggest.
>>
>>
>
> That could possibly be an interesting extension to GTM... but then if GTM
> goes down you application would still not know where to look for the
> standby.
>
> You could also try the approach outlined in a blog posting here, essentially
> using DNS to load balance amongst multiple coordinators.
>
> http://www.translattice.com/blog/Load_Balancing_Postgres-XC.shtml
>
>
> --
> Mason Sharp
>
> TransLattice - http://www.translattice.com
> Distributed and Clustered Database Solutions
>
>
>
> ------------------------------------------------------------------------------
> Learn Graph Databases - Download FREE O'Reilly Book
> "Graph Databases" is the definitive new guide to graph databases and their
> applications. Written by three acclaimed leaders in the field,
> this first edition is now available. Download your free book today!
> http://p.sf.net/sfu/13534_NeoTech
> _______________________________________________
> Postgres-xc-general mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-general
>