postgres-xc-developers Mailing List for Postgres-XC

2012/7/6 Michael Paquier <mic...@gm...>

>
> On 2012/07/06, at 23:18, Andrei Martsinchyk <and...@gm...>
> wrote:
>
> Hi Shankar,
>
> You can safely clone Coordinators by plain copying of the data directory
> and adjusting configuration afterwards. That approach may be used to fix
> your problem or to add a coordinator to existing cluster.
>
> 1. Stop all cluster components.
> 2. Copy coordinator database to the new location.
> 3. Start GTM, GTM proxy if appropriate and Coordinator specifying -D <new
> datadir location>. Make sure you are not running coordinator on the master
> copy of the data directory, they share the same name yet, GTM would not
> allow that.
> 4. Connect psql or other client to the coordinator and create a record in
> pgxc_node table for future "self" entry using CREATE NODE command. You may
> need to adjust connection info for current self, which will be pointing to
> the original coordinator, since the view may be different from the new
> location, like you may want to replace host='localhost' with host = '<IP
> adress>'
> 5. Adjust configuration of the new coordinator, you must change
> pgxc_node_name so it is unique in the cluster; if the new location is on
> the same box you may need to change port to listen on for client
> connections and pooler port. The configuration should match the "self"
> entry you created on previous step.
> 6. Restart the new coordinator, start other cluster components.
> 7. Connect to old coordinators and use CREATE NODE command to make them
> aware of new coordinator.
> 8. Enjoy.
>
> Pinpoint here is that we shouldn't have to stop cluster for a coordinator
> addition. You need to protect your cluster from ddl intrusion while copying
> catalog data to the new coordinator.
>
>
Agree, but master coordinator has to be stopped when copy is started for
the first time, otherwise GTM would not allow it to connect. Though there
is a workaround with another temporary GTM for the copy, if it is not a
production cluster it is simpler just to stop everything.


>
> 2012/7/6 Shankar Hariharan <har...@ya...>
>
>> Hello,
>>
>> Am trying out XC 1.0 in the following configuraiton.
>> Node 1 - Coord1, Datanode1, gtm-proxy1
>> Node 2- Coord2, Datanode2, gtm-proxy2
>> Node 3- Datanode3, gtm
>>
>> I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In
>> addition I missed the pg_hba edit as well. So the first table T1 that I
>> created for distribution from Coord1 was not "visible| from Coord2 but
>> was on all the data nodes.
>> I tried to get Coord2 backinto business in various ways but the first
>> table I created refused to show up on Coord2 :
>> - edit pg_hba and add node on both coord1 and 2. Then run select
>> pgxc_pool_reload();
>> - restart coord 1 and 2
>> - drop node c2 from c1 and c1 from c2 and add them back followed by select
>> pgxc_pool_reload();
>>
>> So I tried to create the same table T1 from Coord2 to observe behavior
>> and it did not like it clearly as all nodes it "wrote" to reported that the
>> table already existed which was good. At this point I could understand that
>> Coord2 and Coord1 are not talking alright so I created a new table from
>> coord1 with replication. This table was visible from both now.
>>
>> Question is should I expect to see the first table, let me call it T1
>> after a while from Coord2 also?
>>
>>
>> thanks,
>> Shankar
>>
>>
>> ------------------------------------------------------------------------------
>> Live Security Virtual Conference
>> Exclusive live event will cover all the ways today's security and
>> threat landscape has changed and how IT managers can respond. Discussions
>> will include endpoint security, mobile security and the latest in malware
>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
>> _______________________________________________
>> Postgres-xc-developers mailing list
>> Pos...@li...
>> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>>
>>
>
>
> --
> Andrei Martsinchyk
>
> StormDB - http://www.stormdb.com
> The Database Cloud
>
>
>
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
>
> _______________________________________________
> Postgres-xc-developers mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>
>


-- 
Andrei Martsinchyk

StormDB - http://www.stormdb.com
The Database Cloud

On 2012/07/06, at 23:18, Andrei Martsinchyk <and...@gm...> wrote:

> Hi Shankar,
> 
> You can safely clone Coordinators by plain copying of the data directory and adjusting configuration afterwards. That approach may be used to fix your problem or to add a coordinator to existing cluster.
> 
> 1. Stop all cluster components.
> 2. Copy coordinator database to the new location.
> 3. Start GTM, GTM proxy if appropriate and Coordinator specifying -D <new datadir location>. Make sure you are not running coordinator on the master copy of the data directory, they share the same name yet, GTM would not allow that. 
> 4. Connect psql or other client to the coordinator and create a record in pgxc_node table for future "self" entry using CREATE NODE command. You may need to adjust connection info for current self, which will be pointing to the original coordinator, since the view may be different from the new location, like you may want to replace host='localhost' with host = '<IP adress>'
> 5. Adjust configuration of the new coordinator, you must change pgxc_node_name so it is unique in the cluster; if the new location is on the same box you may need to change port to listen on for client connections and pooler port. The configuration should match the "self" entry you created on previous step.
> 6. Restart the new coordinator, start other cluster components. 
> 7. Connect to old coordinators and use CREATE NODE command to make them aware of new coordinator.
> 8. Enjoy.
Pinpoint here is that we shouldn't have to stop cluster for a coordinator addition. You need to protect your cluster from ddl intrusion while copying catalog data to the new coordinator.
> 
> 2012/7/6 Shankar Hariharan <har...@ya...>
> Hello,
> 
> Am trying out XC 1.0 in the following configuraiton.
> Node 1 - Coord1, Datanode1, gtm-proxy1
> Node 2- Coord2, Datanode2, gtm-proxy2
> Node 3- Datanode3, gtm
> 
> I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In addition I missed the pg_hba edit as well. So the first table T1 that I created for distribution from Coord1 was not "visible| from Coord2 but was on all the data nodes. 
> I tried to get Coord2 backinto business in various ways but the first table I created refused to show up on Coord2 :
> - edit pg_hba and add node on both coord1 and 2. Then run select pgxc_pool_reload();
> - restart coord 1 and 2
> - drop node c2 from c1 and c1 from c2 and add them back followed by select pgxc_pool_reload();
> 
> So I tried to create the same table T1 from Coord2 to observe behavior and it did not like it clearly as all nodes it "wrote" to reported that the table already existed which was good. At this point I could understand that Coord2 and Coord1 are not talking alright so I created a new table  from coord1 with replication. This table was visible from both now. 
> 
> Question is should I expect to see the first table, let me call it T1 after a while from Coord2 also? 
> 
> 
> thanks,
> Shankar
> 
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> Postgres-xc-developers mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
> 
> 
> 
> 
> -- 
> Andrei Martsinchyk
> 
> StormDB - http://www.stormdb.com
> The Database Cloud
> 
> 
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and 
> threat landscape has changed and how IT managers can respond. Discussions 
> will include endpoint security, mobile security and the latest in malware 
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> Postgres-xc-developers mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers

On 2012/07/07, at 0:03, Shankar Hariharan <har...@ya...> wrote:

> Michael,  read your message on incorrect copy. I was wondering if it is possible to both replicate and distribute a table. Just wondering if it can be used to gather all distributed data in one spot to work around data loss.
You cannot do yet distribution and replication of a table at the same time.
Well, there is no data loss in my bug. We just do not select the correct node when running copy in those particular circumstances.
> 
> thanks,
> Shankar
> 
> From: "pos...@li..." <pos...@li...>
> To: pos...@li... 
> Sent: Friday, July 6, 2012 8:24 AM
> Subject: Postgres-xc-developers Digest, Vol 25, Issue 10
> 
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> Today's Topics:
> 
>   1. Re: Question on gtm-proxy (Michael Paquier)
>   2. Re: Question on gtm-proxy (Ashutosh Bapat)
>   3. Incorrect COPY for partially replicated    tables (Michael Paquier)
>   4. Re: Question on gtm-proxy (Shankar Hariharan)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Fri, 6 Jul 2012 14:00:51 +0900
> From: Michael Paquier <mic...@gm...>
> Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
> To: Shankar Hariharan <har...@ya...>
> Cc: "pos...@li..."
>     <pos...@li...>
> Message-ID:
>     <CAB...@ma...>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> On Fri, Jul 6, 2012 at 1:38 PM, Shankar Hariharan <
> har...@ya...> wrote:
> 
> > Follow up to earlier email. In the setup described below, can I avoid
> > using a gtm-proxy? That is, can I just simply point coordinators to the one
> > gtm running on node 3 ?
> > My initial plan was to just run the gtm on node 3 then I thought I could
> > try a datanode without a local coordinator which was why I put these two
> > together on node 3.
> > thanks,
> >
> GTM proxy is not a mandatory element in an XC cluster.
> So yes, you can connect directly a Coordinator or a Datanode to a GTM.
> -- 
> Michael Paquier
> http://michael.otacoo.com
> -------------- next part --------------
> An HTML attachment was scrubbed...
> 
> ------------------------------
> 
> Message: 2
> Date: Fri, 6 Jul 2012 10:55:37 +0530
> From: Ashutosh Bapat <ash...@en...>
> Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
> To: Shankar Hariharan <har...@ya...>
> Cc: "pos...@li..."
>     <pos...@li...>
> Message-ID:
>     <CAF...@ma...>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> Hi Shankar,
> Running gtm-proxy has shown to improve the performance, because it lessens
> the load on GTM, by serving requests locally. Why do you want the
> coordinators to connect directly to the GTM? Are you seeing any performance
> improvement from doing that?
> 
> On Fri, Jul 6, 2012 at 10:08 AM, Shankar Hariharan <
> har...@ya...> wrote:
> 
> > Follow up to earlier email. In the setup described below, can I avoid
> > using a gtm-proxy? That is, can I just simply point coordinators to the one
> > gtm running on node 3 ?
> > My initial plan was to just run the gtm on node 3 then I thought I could
> > try a datanode without a local coordinator which was why I put these two
> > together on node 3.
> > thanks,
> > Shankar
> >
> >  ------------------------------
> > *From:* Shankar Hariharan <har...@ya...>
> > *To:* "pos...@li..." <
> > pos...@li...>
> > *Sent:* Thursday, July 5, 2012 11:35 PM
> > *Subject:* Question on multiple coordinators
> >
> > Hello,
> >
> > Am trying out XC 1.0 in the following configuraiton.
> > Node 1 - Coord1, Datanode1, gtm-proxy1
> > Node 2- Coord2, Datanode2, gtm-proxy2
> > Node 3- Datanode3, gtm
> >
> > I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In
> > addition I missed the pg_hba edit as well. So the first table T1 that I
> > created for distribution from Coord1 was not "visible| from Coord2 but
> > was on all the data nodes.
> > I tried to get Coord2 backinto business in various ways but the first
> > table I created refused to show up on Coord2 :
> > - edit pg_hba and add node on both coord1 and 2. Then run select
> > pgxc_pool_reload();
> > - restart coord 1 and 2
> > - drop node c2 from c1 and c1 from c2 and add them back followed by select
> > pgxc_pool_reload();
> >
> > So I tried to create the same table T1 from Coord2 to observe behavior
> > and it did not like it clearly as all nodes it "wrote" to reported that the
> > table already existed which was good. At this point I could understand that
> > Coord2 and Coord1 are not talking alright so I created a new table from
> > coord1 with replication. This table was visible from both now.
> >
> > Question is should I expect to see the first table, let me call it T1
> > after a while from Coord2 also?
> >
> >
> > thanks,
> > Shankar
> >
> >
> >
> >
> > ------------------------------------------------------------------------------
> > Live Security Virtual Conference
> > Exclusive live event will cover all the ways today's security and
> > threat landscape has changed and how IT managers can respond. Discussions
> > will include endpoint security, mobile security and the latest in malware
> > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> > _______________________________________________
> > Postgres-xc-developers mailing list
> > Pos...@li...
> > https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
> >
> >
> 
> 
> -- 
> Best Wishes,
> Ashutosh Bapat
> EntepriseDB Corporation
> The Enterprise Postgres Company
> -------------- next part --------------
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> ------------------------------
> 
> Message: 3
> Date: Fri, 6 Jul 2012 18:07:44 +0900
> From: Michael Paquier <mic...@gm...>
> Subject: [Postgres-xc-developers] Incorrect COPY for partially
>     replicated    tables
> To: Postgres-XC mailing list
>     <pos...@li...>
> Message-ID:
>     <CAB7nPqR=dA4=Hbw...@ma...>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> Hi all,
> 
> While testing data redistribution I found this bug with COPY.
> It is reproducible with master, and very probably with 1.0 stable.
> postgres=# create table aa (a int) distribute by replication to node dn2;
> CREATE TABLE
> postgres=# insert into aa values (generate_series(1,10));
> INSERT 0 10
> postgres=# copy aa to stdout; -- no output here
> postgres=#
> I'll investigate this problem on Monday. For the time being this bug is
> registered here:
> https://sourceforge.net/tracker/?func=detail&aid=3540784&group_id=311227&atid=1310232
> 
> Regards,
> -- 
> Michael Paquier
> http://michael.otacoo.com
> -------------- next part --------------
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> ------------------------------
> 
> Message: 4
> Date: Fri, 6 Jul 2012 06:22:12 -0700 (PDT)
> From: Shankar Hariharan <har...@ya...>
> Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
> To: Ashutosh Bapat <ash...@en...>
> Cc: "pos...@li..."
>     <pos...@li...>
> Message-ID:
>     <134...@we...>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> Hi Ashutosh,
> I was trying to size the load on a server and was wondering if ?a GTM could be shared w/o much performance overhead between a small number of datanodes and coordinators. I will post my findings here.
> thanks,
> Shankar
> 
> 
> ________________________________
> From: Ashutosh Bapat <ash...@en...>
> To: Shankar Hariharan <har...@ya...> 
> Cc: "pos...@li..." <pos...@li...> 
> Sent: Friday, July 6, 2012 12:25 AM
> Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
> 
> 
> Hi Shankar,
> Running gtm-proxy has shown to improve the performance, because it lessens the load on GTM, by serving requests locally. Why do you want the coordinators to connect directly to the GTM? Are you seeing any performance improvement from doing that?
> 
> 
> On Fri, Jul 6, 2012 at 10:08 AM, Shankar Hariharan <har...@ya...> wrote:
> 
> Follow up to earlier email. In the setup described below, can I avoid using a gtm-proxy? That is, can I just simply point coordinators to the one gtm running on node 3 ?
> >My initial plan was to just run the gtm on node 3 then I thought I could try a datanode without a local coordinator which was why I put these two together on node 3.
> >thanks,
> >Shankar
> >
> >
> >
> >________________________________
> > From: Shankar Hariharan <har...@ya...>
> >To: "pos...@li..." <pos...@li...> 
> >Sent: Thursday, July 5, 2012 11:35 PM
> >Subject: Question on multiple coordinators
> > 
> >
> >Hello,
> >
> >
> >Am trying out XC 1.0 in the following configuraiton.
> >Node 1 - Coord1, Datanode1, gtm-proxy1
> >Node 2-?Coord2, Datanode2, gtm-proxy2
> >Node 3-?Datanode3, gtm
> >
> >
> >I setup all nodes but forgot to add Coord1 to?Coord2 and vice versa. In addition I missed the pg_hba edit as well.?So the first table T1 that I created for distribution from?Coord1?was not "visible| from?Coord2 but was on all the data nodes.?
> >I tried to get Coord2 backinto business in various ways but the first table I created refused to show up on Coord2 :
> >- edit pg_hba and add node on both coord1 and 2. Then run?select pgxc_pool_reload();
> >- restart coord 1 and 2
> >- drop node c2 from c1 and c1 from c2 and add them back followed by?select pgxc_pool_reload();
> >
> >
> >So I tried to create the same table T1 from?Coord2 to observe behavior and it did not like it clearly as all nodes it "wrote" to reported that the table already existed which was good. At this point I could understand that Coord2 and Coord1 are not talking alright so I created a new table from coord1 with replication. This table was visible from both now.?
> >
> >
> >Question is should I expect to see the first table, let me call it T1 after a while from Coord2 also??
> >
> >
> >
> >
> >thanks,
> >Shankar
> >
> >
> >------------------------------------------------------------------------------
> >Live Security Virtual Conference
> >Exclusive live event will cover all the ways today's security and
> >threat landscape has changed and how IT managers can respond. Discussions
> >will include endpoint security, mobile security and the latest in malware
> >threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> >_______________________________________________
> >Postgres-xc-developers mailing list
> >Pos...@li...
> >https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
> >
> >
> 
> 
> -- 
> Best Wishes,
> Ashutosh Bapat
> EntepriseDB Corporation
> The Enterprise Postgres Company
> -------------- next part --------------
> An HTML attachment was scrubbed...
> 
> ------------------------------
> 
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and 
> threat landscape has changed and how IT managers can respond. Discussions 
> will include endpoint security, mobile security and the latest in malware 
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> 
> ------------------------------
> 
> _______________________________________________
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> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
> 
> 
> End of Postgres-xc-developers Digest, Vol 25, Issue 10
> ******************************************************
> 
> 
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and 
> threat landscape has changed and how IT managers can respond. Discussions 
> will include endpoint security, mobile security and the latest in malware 
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
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As planned I ran some tests using PGBench on this setup :

Node 1 - Coord1, Datanode1, gtm-proxy1
Node 2- Coord2, Datanode2, gtm-proxy2
Node 3- Datanode3, gtm

I was connecting via Coord1 for these tests:
- scale factor of 30 used
- tests run using the following input parameters for pgbench:


ClientsThreadsDurationTransactions
111006204
221009960
4410012880
6610016768
8810019758
101010021944
121210020674

The run went well until the 8 clients. I started seeing errors on 10 clients onwards and eventually the 14 client run has been hanging around for over an hour now. The errors I have been seeing on console are the following :

pgbench console :
Client 8 aborted in state 12: ERROR:  GTM error, could not obtain snapshot

Client 0 aborted in state 13: ERROR:  maximum number of prepared transactions reached
Client 7 aborted in state 13: ERROR:  maximum number of prepared transactions reached
Client 11 aborted in state 13: ERROR:  maximum number of prepared transactions reached
Client 9 aborted in state 13: ERROR:  maximum number of prepared transactions reached

node console:
ERROR:  GTM error, could not obtain snapshot
STATEMENT:  INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (253, 26, 1888413, -817, CURRENT_TIMESTAMP);
ERROR:  maximum number of prepared transactions reached
HINT:  Increase max_prepared_transactions (currently 10).
STATEMENT:  PREPARE TRANSACTION 'T201428'
ERROR:  maximum number of prepared transactions reached
STATEMENT:  END;
ERROR:  maximum number of prepared transactions reached
STATEMENT:  END;
ERROR:  maximum number of prepared transactions reached
STATEMENT:  END;
ERROR:  maximum number of prepared transactions reached
STATEMENT:  END;
ERROR:  GTM error, could not obtain snapshot
STATEMENT:  INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (140, 29, 2416403, -4192, CURRENT_TIMESTAMP);

I was also watching the processes on each node and see the following for the 14 client run:


Node1 :
postgres 25571 10511  0 04:41 ?        00:00:02 postgres: postgres postgres ::1(33481) TRUNCATE TABLE waiting
postgres 25620 11694  0 04:46 ?        00:00:00 postgres: postgres postgres pgbench-address (50388) TRUNCATE TABLE

Node2:
postgres 10979  9631  0 Jul05 ?        00:00:42 postgres: postgres postgres coord1-address(57357) idle in transaction


Node3:

postgres 20264  9911  0 08:35 ?        00:00:05 postgres: postgres postgres coord1-address(51406) TRUNCATE TABLE waiting



I was going to restart the processes on all nodes and start over but did not want to lose this data as it could be useful information.

Any explanation on the above issue is much appreciated. I will try the next run with a higher value set for  max_prepared_transactions. Any recommendations for a good value on this front?


thanks,
Shankar 



________________________________
 From: Shankar Hariharan <har...@ya...>
To: Ashutosh Bapat <ash...@en...> 
Cc: "pos...@li..." <pos...@li...> 
Sent: Friday, July 6, 2012 8:22 AM
Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
 

Hi Ashutosh,
I was trying to size the load on a server and was wondering if  a GTM could be shared w/o much performance overhead between a small number of datanodes and coordinators. I will post my findings here.
thanks,
Shankar


________________________________
 From: Ashutosh Bapat <ash...@en...>
To: Shankar Hariharan <har...@ya...> 
Cc: "pos...@li..." <pos...@li...> 
Sent: Friday, July 6, 2012 12:25 AM
Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
 

Hi Shankar,
Running gtm-proxy has shown to improve the performance, because it lessens the load on GTM, by serving requests locally. Why do you want the coordinators to connect directly to the GTM? Are you seeing any performance improvement from doing that?


On Fri, Jul 6, 2012 at 10:08 AM, Shankar Hariharan <har...@ya...> wrote:

Follow up to earlier email. In the setup described below, can I avoid using a gtm-proxy? That is, can I just simply point coordinators to the one gtm running on node 3 ?
>My initial plan was to just run the gtm on node 3 then I thought I could try a datanode without a local coordinator which was why I put these two together on node 3.
>thanks,
>Shankar
>
>
>
>________________________________
> From: Shankar Hariharan <har...@ya...>
>To: "pos...@li..." <pos...@li...> 
>Sent: Thursday, July 5, 2012 11:35 PM
>Subject: Question on multiple coordinators
> 
>
>Hello,
>
>
>Am trying out XC 1.0 in the following configuraiton.
>Node 1 - Coord1, Datanode1, gtm-proxy1
>Node 2- Coord2, Datanode2, gtm-proxy2
>Node 3- Datanode3, gtm
>
>
>I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In addition I missed the pg_hba edit as well. So the first table T1 that I created for distribution from Coord1 was not "visible| from Coord2 but was on all the data nodes. 
>I tried to get Coord2 backinto business in various ways but the first table I created refused to show up on Coord2 :
>- edit pg_hba and add node on both coord1 and 2. Then run select pgxc_pool_reload();
>- restart coord 1 and 2
>- drop node c2 from c1 and c1 from c2 and add them back followed by select pgxc_pool_reload();
>
>
>So I tried to create the same table T1 from Coord2 to observe behavior and it did not like it clearly as all nodes it "wrote" to reported that the table already existed which was good. At this point I could understand that Coord2 and Coord1 are not talking alright so I created a new table from coord1 with replication. This table was visible from both now. 
>
>
>Question is should I expect to see the first table, let me call it T1 after a while from Coord2 also? 
>
>
>
>
>thanks,
>Shankar
>
>
>------------------------------------------------------------------------------
>Live Security Virtual Conference
>Exclusive live event will cover all the ways today's security and
>threat landscape has changed and how IT managers can respond. Discussions
>will include endpoint security, mobile security and the latest in malware
>threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
>_______________________________________________
>Postgres-xc-developers mailing list
>Pos...@li...
>https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>
>


-- 
Best Wishes,
Ashutosh Bapat
EntepriseDB Corporation
The Enterprise Postgres Company

Hi Shankar,

Yeah, the GTM might be able to scale a bit to some level, but after
that having the proxies around on each node makes much more sense. It
also helps reduce the direct CPU load on the GTM node. And the proxies
shouldn't consume that much CPU by themselves too. Unless you are
trying a CPU intensive benchmark, but most benchmarks try to churn up
IO..

Regards,
Nikhils

On Fri, Jul 6, 2012 at 9:22 AM, Shankar Hariharan
<har...@ya...> wrote:
> Hi Ashutosh,
> I was trying to size the load on a server and was wondering if  a GTM could
> be shared w/o much performance overhead between a small number of datanodes
> and coordinators. I will post my findings here.
> thanks,
> Shankar
>
> ________________________________
> From: Ashutosh Bapat <ash...@en...>
> To: Shankar Hariharan <har...@ya...>
> Cc: "pos...@li..."
> <pos...@li...>
> Sent: Friday, July 6, 2012 12:25 AM
> Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
>
> Hi Shankar,
> Running gtm-proxy has shown to improve the performance, because it lessens
> the load on GTM, by serving requests locally. Why do you want the
> coordinators to connect directly to the GTM? Are you seeing any performance
> improvement from doing that?
>
> On Fri, Jul 6, 2012 at 10:08 AM, Shankar Hariharan
> <har...@ya...> wrote:
>
> Follow up to earlier email. In the setup described below, can I avoid using
> a gtm-proxy? That is, can I just simply point coordinators to the one gtm
> running on node 3 ?
> My initial plan was to just run the gtm on node 3 then I thought I could try
> a datanode without a local coordinator which was why I put these two
> together on node 3.
> thanks,
> Shankar
>
> ________________________________
> From: Shankar Hariharan <har...@ya...>
> To: "pos...@li..."
> <pos...@li...>
> Sent: Thursday, July 5, 2012 11:35 PM
> Subject: Question on multiple coordinators
>
> Hello,
>
> Am trying out XC 1.0 in the following configuraiton.
> Node 1 - Coord1, Datanode1, gtm-proxy1
> Node 2- Coord2, Datanode2, gtm-proxy2
> Node 3- Datanode3, gtm
>
> I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In
> addition I missed the pg_hba edit as well. So the first table T1 that I
> created for distribution from Coord1 was not "visible| from Coord2 but was
> on all the data nodes.
> I tried to get Coord2 backinto business in various ways but the first table
> I created refused to show up on Coord2 :
> - edit pg_hba and add node on both coord1 and 2. Then run select
> pgxc_pool_reload();
> - restart coord 1 and 2
> - drop node c2 from c1 and c1 from c2 and add them back followed by select
> pgxc_pool_reload();
>
> So I tried to create the same table T1 from Coord2 to observe behavior and
> it did not like it clearly as all nodes it "wrote" to reported that the
> table already existed which was good. At this point I could understand that
> Coord2 and Coord1 are not talking alright so I created a new table from
> coord1 with replication. This table was visible from both now.
>
> Question is should I expect to see the first table, let me call it T1 after
> a while from Coord2 also?
>
>
> thanks,
> Shankar
>
>
>
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> Postgres-xc-developers mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>
>
>
>
> --
> Best Wishes,
> Ashutosh Bapat
> EntepriseDB Corporation
> The Enterprise Postgres Company
>
>
>
>
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> Postgres-xc-developers mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>



-- 
StormDB - http://www.stormdb.com
The Database Cloud

Thanks Andrei. I will try this out. Appreciate the help.


________________________________
 From: Andrei Martsinchyk <and...@gm...>
To: Shankar Hariharan <har...@ya...> 
Cc: "pos...@li..." <pos...@li...> 
Sent: Friday, July 6, 2012 9:18 AM
Subject: Re: [Postgres-xc-developers] Question on multiple coordinators
 

Hi Shankar,

You can safely clone Coordinators by plain copying of the data directory and adjusting configuration afterwards. That approach may be used to fix your problem or to add a coordinator to existing cluster.

1. Stop all cluster components.
2. Copy coordinator database to the new location.
3. Start GTM, GTM proxy if appropriate and Coordinator specifying -D <new datadir location>. Make sure you are not running coordinator on the master copy of the data directory, they share the same name yet, GTM would not allow that. 
4. Connect psql or other client to the coordinator and create a record in pgxc_node table for future "self" entry using CREATE NODE command. You may need to adjust connection info for current self, which will be pointing to the original coordinator, since the view may be different from the new location, like you may want to replace host='localhost' with host = '<IP adress>'
5. Adjust configuration of the new coordinator, you must change pgxc_node_name so it is unique in the cluster; if the new location is on the same box you may need to change port to listen on for client connections and pooler port. The configuration should match the "self" entry you created on previous step.
6. Restart the new coordinator, start other cluster components. 
7. Connect to old coordinators and use CREATE NODE command to make them aware of new coordinator.
8. Enjoy.


2012/7/6 Shankar Hariharan <har...@ya...>

Hello,
>
>
>Am trying out XC 1.0 in the following configuraiton.
>Node 1 - Coord1, Datanode1, gtm-proxy1
>Node 2- Coord2, Datanode2, gtm-proxy2
>Node 3- Datanode3, gtm
>
>
>I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In addition I missed the pg_hba edit as well. So the first table T1 that I created for distribution from Coord1 was not "visible| from Coord2 but was on all the data nodes. 
>I tried to get Coord2 backinto business in various ways but the first table I created refused to show up on Coord2 :
>- edit pg_hba and add node on both coord1 and 2. Then run select pgxc_pool_reload();
>- restart coord 1 and 2
>- drop node c2 from c1 and c1 from c2 and add them back followed by select pgxc_pool_reload();
>
>
>So I tried to create the same table T1 from Coord2 to observe behavior and it did not like it clearly as all nodes it "wrote" to reported that the table already existed which was good. At this point I could understand that Coord2 and Coord1 are not talking alright so I created a new table from coord1 with replication. This table was visible from both now. 
>
>
>Question is should I expect to see the first table, let me call it T1 after a while from Coord2 also? 
>
>
>
>
>thanks,
>Shankar
>------------------------------------------------------------------------------
>Live Security Virtual Conference
>Exclusive live event will cover all the ways today's security and
>threat landscape has changed and how IT managers can respond. Discussions
>will include endpoint security, mobile security and the latest in malware
>threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
>_______________________________________________
>Postgres-xc-developers mailing list
>Pos...@li...
>https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>
>


-- 
Andrei Martsinchyk

StormDB - http://www.stormdb.com/
The Database Cloud

Michael,  read your message on incorrect copy. I was wondering if it is possible to both replicate and distribute a table. Just wondering if it can be used to gather all distributed data in one spot to work around data loss.

thanks,
Shankar


________________________________
 From: "pos...@li..." <pos...@li...>
To: pos...@li... 
Sent: Friday, July 6, 2012 8:24 AM
Subject: Postgres-xc-developers Digest, Vol 25, Issue 10
 
Send Postgres-xc-developers mailing list submissions to
    pos...@li...

To subscribe or unsubscribe via the World Wide Web, visit
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When replying, please edit your Subject line so it is more specific
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Today's Topics:

   1. Re: Question on gtm-proxy (Michael Paquier)
   2. Re: Question on gtm-proxy (Ashutosh Bapat)
   3. Incorrect COPY for partially replicated    tables (Michael Paquier)
   4. Re: Question on gtm-proxy (Shankar Hariharan)


----------------------------------------------------------------------

Message: 1
Date: Fri, 6 Jul 2012 14:00:51 +0900
From: Michael Paquier <mic...@gm...>
Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
To: Shankar Hariharan <har...@ya...>
Cc: "pos...@li..."
    <pos...@li...>
Message-ID:
    <CAB...@ma...>
Content-Type: text/plain; charset="iso-8859-1"

On Fri, Jul 6, 2012 at 1:38 PM, Shankar Hariharan <
har...@ya...> wrote:

> Follow up to earlier email. In the setup described below, can I avoid
> using a gtm-proxy? That is, can I just simply point coordinators to the one
> gtm running on node 3 ?
> My initial plan was to just run the gtm on node 3 then I thought I could
> try a datanode without a local coordinator which was why I put these two
> together on node 3.
> thanks,
>
GTM proxy is not a mandatory element in an XC cluster.
So yes, you can connect directly a Coordinator or a Datanode to a GTM.
-- 
Michael Paquier
http://michael.otacoo.com
-------------- next part --------------
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------------------------------

Message: 2
Date: Fri, 6 Jul 2012 10:55:37 +0530
From: Ashutosh Bapat <ash...@en...>
Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
To: Shankar Hariharan <har...@ya...>
Cc: "pos...@li..."
    <pos...@li...>
Message-ID:
    <CAF...@ma...>
Content-Type: text/plain; charset="iso-8859-1"

Hi Shankar,
Running gtm-proxy has shown to improve the performance, because it lessens
the load on GTM, by serving requests locally. Why do you want the
coordinators to connect directly to the GTM? Are you seeing any performance
improvement from doing that?

On Fri, Jul 6, 2012 at 10:08 AM, Shankar Hariharan <
har...@ya...> wrote:

> Follow up to earlier email. In the setup described below, can I avoid
> using a gtm-proxy? That is, can I just simply point coordinators to the one
> gtm running on node 3 ?
> My initial plan was to just run the gtm on node 3 then I thought I could
> try a datanode without a local coordinator which was why I put these two
> together on node 3.
> thanks,
> Shankar
>
>   ------------------------------
> *From:* Shankar Hariharan <har...@ya...>
> *To:* "pos...@li..." <
> pos...@li...>
> *Sent:* Thursday, July 5, 2012 11:35 PM
> *Subject:* Question on multiple coordinators
>
> Hello,
>
> Am trying out XC 1.0 in the following configuraiton.
> Node 1 - Coord1, Datanode1, gtm-proxy1
> Node 2- Coord2, Datanode2, gtm-proxy2
> Node 3- Datanode3, gtm
>
> I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In
> addition I missed the pg_hba edit as well. So the first table T1 that I
> created for distribution from Coord1 was not "visible| from Coord2 but
> was on all the data nodes.
> I tried to get Coord2 backinto business in various ways but the first
> table I created refused to show up on Coord2 :
> - edit pg_hba and add node on both coord1 and 2. Then run select
> pgxc_pool_reload();
> - restart coord 1 and 2
> - drop node c2 from c1 and c1 from c2 and add them back followed by select
> pgxc_pool_reload();
>
> So I tried to create the same table T1 from Coord2 to observe behavior
> and it did not like it clearly as all nodes it "wrote" to reported that the
> table already existed which was good. At this point I could understand that
> Coord2 and Coord1 are not talking alright so I created a new table from
> coord1 with replication. This table was visible from both now.
>
> Question is should I expect to see the first table, let me call it T1
> after a while from Coord2 also?
>
>
> thanks,
> Shankar
>
>
>
>
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> Postgres-xc-developers mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>
>


-- 
Best Wishes,
Ashutosh Bapat
EntepriseDB Corporation
The Enterprise Postgres Company
-------------- next part --------------
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------------------------------

Message: 3
Date: Fri, 6 Jul 2012 18:07:44 +0900
From: Michael Paquier <mic...@gm...>
Subject: [Postgres-xc-developers] Incorrect COPY for partially
    replicated    tables
To: Postgres-XC mailing list
    <pos...@li...>
Message-ID:
    <CAB7nPqR=dA4=Hbw...@ma...>
Content-Type: text/plain; charset="iso-8859-1"

Hi all,

While testing data redistribution I found this bug with COPY.
It is reproducible with master, and very probably with 1.0 stable.
postgres=# create table aa (a int) distribute by replication to node dn2;
CREATE TABLE
postgres=# insert into aa values (generate_series(1,10));
INSERT 0 10
postgres=# copy aa to stdout; -- no output here
postgres=#
I'll investigate this problem on Monday. For the time being this bug is
registered here:
https://sourceforge.net/tracker/?func=detail&aid=3540784&group_id=311227&atid=1310232

Regards,
-- 
Michael Paquier
http://michael.otacoo.com
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------------------------------

Message: 4
Date: Fri, 6 Jul 2012 06:22:12 -0700 (PDT)
From: Shankar Hariharan <har...@ya...>
Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
To: Ashutosh Bapat <ash...@en...>
Cc: "pos...@li..."
    <pos...@li...>
Message-ID:
    <134...@we...>
Content-Type: text/plain; charset="iso-8859-1"

Hi Ashutosh,
I was trying to size the load on a server and was wondering if ?a GTM could be shared w/o much performance overhead between a small number of datanodes and coordinators. I will post my findings here.
thanks,
Shankar


________________________________
From: Ashutosh Bapat <ash...@en...>
To: Shankar Hariharan <har...@ya...> 
Cc: "pos...@li..." <pos...@li...> 
Sent: Friday, July 6, 2012 12:25 AM
Subject: Re: [Postgres-xc-developers] Question on gtm-proxy


Hi Shankar,
Running gtm-proxy has shown to improve the performance, because it lessens the load on GTM, by serving requests locally. Why do you want the coordinators to connect directly to the GTM? Are you seeing any performance improvement from doing that?


On Fri, Jul 6, 2012 at 10:08 AM, Shankar Hariharan <har...@ya...> wrote:

Follow up to earlier email. In the setup described below, can I avoid using a gtm-proxy? That is, can I just simply point coordinators to the one gtm running on node 3 ?
>My initial plan was to just run the gtm on node 3 then I thought I could try a datanode without a local coordinator which was why I put these two together on node 3.
>thanks,
>Shankar
>
>
>
>________________________________
> From: Shankar Hariharan <har...@ya...>
>To: "pos...@li..." <pos...@li...> 
>Sent: Thursday, July 5, 2012 11:35 PM
>Subject: Question on multiple coordinators
> 
>
>Hello,
>
>
>Am trying out XC 1.0 in the following configuraiton.
>Node 1 - Coord1, Datanode1, gtm-proxy1
>Node 2-?Coord2, Datanode2, gtm-proxy2
>Node 3-?Datanode3, gtm
>
>
>I setup all nodes but forgot to add Coord1 to?Coord2 and vice versa. In addition I missed the pg_hba edit as well.?So the first table T1 that I created for distribution from?Coord1?was not "visible| from?Coord2 but was on all the data nodes.?
>I tried to get Coord2 backinto business in various ways but the first table I created refused to show up on Coord2 :
>- edit pg_hba and add node on both coord1 and 2. Then run?select pgxc_pool_reload();
>- restart coord 1 and 2
>- drop node c2 from c1 and c1 from c2 and add them back followed by?select pgxc_pool_reload();
>
>
>So I tried to create the same table T1 from?Coord2 to observe behavior and it did not like it clearly as all nodes it "wrote" to reported that the table already existed which was good. At this point I could understand that Coord2 and Coord1 are not talking alright so I created a new table from coord1 with replication. This table was visible from both now.?
>
>
>Question is should I expect to see the first table, let me call it T1 after a while from Coord2 also??
>
>
>
>
>thanks,
>Shankar
>
>
>------------------------------------------------------------------------------
>Live Security Virtual Conference
>Exclusive live event will cover all the ways today's security and
>threat landscape has changed and how IT managers can respond. Discussions
>will include endpoint security, mobile security and the latest in malware
>threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
>_______________________________________________
>Postgres-xc-developers mailing list
>Pos...@li...
>https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>
>


-- 
Best Wishes,
Ashutosh Bapat
EntepriseDB Corporation
The Enterprise Postgres Company
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------------------------------

------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/

------------------------------

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Postgres-xc-developers mailing list
Pos...@li...
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End of Postgres-xc-developers Digest, Vol 25, Issue 10
******************************************************

Hi Shankar,

You can safely clone Coordinators by plain copying of the data directory
and adjusting configuration afterwards. That approach may be used to fix
your problem or to add a coordinator to existing cluster.

1. Stop all cluster components.
2. Copy coordinator database to the new location.
3. Start GTM, GTM proxy if appropriate and Coordinator specifying -D <new
datadir location>. Make sure you are not running coordinator on the master
copy of the data directory, they share the same name yet, GTM would not
allow that.
4. Connect psql or other client to the coordinator and create a record in
pgxc_node table for future "self" entry using CREATE NODE command. You may
need to adjust connection info for current self, which will be pointing to
the original coordinator, since the view may be different from the new
location, like you may want to replace host='localhost' with host = '<IP
adress>'
5. Adjust configuration of the new coordinator, you must change
pgxc_node_name so it is unique in the cluster; if the new location is on
the same box you may need to change port to listen on for client
connections and pooler port. The configuration should match the "self"
entry you created on previous step.
6. Restart the new coordinator, start other cluster components.
7. Connect to old coordinators and use CREATE NODE command to make them
aware of new coordinator.
8. Enjoy.

2012/7/6 Shankar Hariharan <har...@ya...>

> Hello,
>
> Am trying out XC 1.0 in the following configuraiton.
> Node 1 - Coord1, Datanode1, gtm-proxy1
> Node 2- Coord2, Datanode2, gtm-proxy2
> Node 3- Datanode3, gtm
>
> I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In
> addition I missed the pg_hba edit as well. So the first table T1 that I
> created for distribution from Coord1 was not "visible| from Coord2 but
> was on all the data nodes.
> I tried to get Coord2 backinto business in various ways but the first
> table I created refused to show up on Coord2 :
> - edit pg_hba and add node on both coord1 and 2. Then run select
> pgxc_pool_reload();
> - restart coord 1 and 2
> - drop node c2 from c1 and c1 from c2 and add them back followed by select
> pgxc_pool_reload();
>
> So I tried to create the same table T1 from Coord2 to observe behavior
> and it did not like it clearly as all nodes it "wrote" to reported that the
> table already existed which was good. At this point I could understand that
> Coord2 and Coord1 are not talking alright so I created a new table from
> coord1 with replication. This table was visible from both now.
>
> Question is should I expect to see the first table, let me call it T1
> after a while from Coord2 also?
>
>
> thanks,
> Shankar
>
>
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> Postgres-xc-developers mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>
>


-- 
Andrei Martsinchyk

StormDB - http://www.stormdb.com
The Database Cloud

Thanks Michael. Based on your experience, is that good behavior to have a GTM shared across multiple coordinators/datanodes? I do plan to run some tests to observe behavior but would like to understand if there are some metrics around this already.

thanks,
Shankar


________________________________
 From: Michael Paquier <mic...@gm...>
To: Shankar Hariharan <har...@ya...> 
Cc: "pos...@li..." <pos...@li...> 
Sent: Friday, July 6, 2012 12:00 AM
Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
 




On Fri, Jul 6, 2012 at 1:38 PM, Shankar Hariharan <har...@ya...> wrote:

Follow up to earlier email. In the setup described below, can I avoid using a gtm-proxy? That is, can I just simply point coordinators to the one gtm running on node 3 ?
>My initial plan was to just run the gtm on node 3 then I thought I could try a datanode without a local coordinator which was why I put these two together on node 3.
>thanks,
GTM proxy is not a mandatory element in an XC cluster.
So yes, you can connect directly a Coordinator or a Datanode to a GTM.
-- 
Michael Paquier
http://michael.otacoo.com

Hi Ashutosh,
I was trying to size the load on a server and was wondering if  a GTM could be shared w/o much performance overhead between a small number of datanodes and coordinators. I will post my findings here.
thanks,
Shankar


________________________________
 From: Ashutosh Bapat <ash...@en...>
To: Shankar Hariharan <har...@ya...> 
Cc: "pos...@li..." <pos...@li...> 
Sent: Friday, July 6, 2012 12:25 AM
Subject: Re: [Postgres-xc-developers] Question on gtm-proxy
 

Hi Shankar,
Running gtm-proxy has shown to improve the performance, because it lessens the load on GTM, by serving requests locally. Why do you want the coordinators to connect directly to the GTM? Are you seeing any performance improvement from doing that?


On Fri, Jul 6, 2012 at 10:08 AM, Shankar Hariharan <har...@ya...> wrote:

Follow up to earlier email. In the setup described below, can I avoid using a gtm-proxy? That is, can I just simply point coordinators to the one gtm running on node 3 ?
>My initial plan was to just run the gtm on node 3 then I thought I could try a datanode without a local coordinator which was why I put these two together on node 3.
>thanks,
>Shankar
>
>
>
>________________________________
> From: Shankar Hariharan <har...@ya...>
>To: "pos...@li..." <pos...@li...> 
>Sent: Thursday, July 5, 2012 11:35 PM
>Subject: Question on multiple coordinators
> 
>
>Hello,
>
>
>Am trying out XC 1.0 in the following configuraiton.
>Node 1 - Coord1, Datanode1, gtm-proxy1
>Node 2- Coord2, Datanode2, gtm-proxy2
>Node 3- Datanode3, gtm
>
>
>I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In addition I missed the pg_hba edit as well. So the first table T1 that I created for distribution from Coord1 was not "visible| from Coord2 but was on all the data nodes. 
>I tried to get Coord2 backinto business in various ways but the first table I created refused to show up on Coord2 :
>- edit pg_hba and add node on both coord1 and 2. Then run select pgxc_pool_reload();
>- restart coord 1 and 2
>- drop node c2 from c1 and c1 from c2 and add them back followed by select pgxc_pool_reload();
>
>
>So I tried to create the same table T1 from Coord2 to observe behavior and it did not like it clearly as all nodes it "wrote" to reported that the table already existed which was good. At this point I could understand that Coord2 and Coord1 are not talking alright so I created a new table from coord1 with replication. This table was visible from both now. 
>
>
>Question is should I expect to see the first table, let me call it T1 after a while from Coord2 also? 
>
>
>
>
>thanks,
>Shankar
>
>
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-- 
Best Wishes,
Ashutosh Bapat
EntepriseDB Corporation
The Enterprise Postgres Company

Hi all,

While testing data redistribution I found this bug with COPY.
It is reproducible with master, and very probably with 1.0 stable.
postgres=# create table aa (a int) distribute by replication to node dn2;
CREATE TABLE
postgres=# insert into aa values (generate_series(1,10));
INSERT 0 10
postgres=# copy aa to stdout; -- no output here
postgres=#
I'll investigate this problem on Monday. For the time being this bug is
registered here:
https://sourceforge.net/tracker/?func=detail&aid=3540784&group_id=311227&atid=1310232

Regards,
-- 
Michael Paquier
http://michael.otacoo.com

Hi Shankar,
Running gtm-proxy has shown to improve the performance, because it lessens
the load on GTM, by serving requests locally. Why do you want the
coordinators to connect directly to the GTM? Are you seeing any performance
improvement from doing that?

On Fri, Jul 6, 2012 at 10:08 AM, Shankar Hariharan <
har...@ya...> wrote:

> Follow up to earlier email. In the setup described below, can I avoid
> using a gtm-proxy? That is, can I just simply point coordinators to the one
> gtm running on node 3 ?
> My initial plan was to just run the gtm on node 3 then I thought I could
> try a datanode without a local coordinator which was why I put these two
> together on node 3.
> thanks,
> Shankar
>
>   ------------------------------
> *From:* Shankar Hariharan <har...@ya...>
> *To:* "pos...@li..." <
> pos...@li...>
> *Sent:* Thursday, July 5, 2012 11:35 PM
> *Subject:* Question on multiple coordinators
>
> Hello,
>
> Am trying out XC 1.0 in the following configuraiton.
> Node 1 - Coord1, Datanode1, gtm-proxy1
> Node 2- Coord2, Datanode2, gtm-proxy2
> Node 3- Datanode3, gtm
>
> I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In
> addition I missed the pg_hba edit as well. So the first table T1 that I
> created for distribution from Coord1 was not "visible| from Coord2 but
> was on all the data nodes.
> I tried to get Coord2 backinto business in various ways but the first
> table I created refused to show up on Coord2 :
> - edit pg_hba and add node on both coord1 and 2. Then run select
> pgxc_pool_reload();
> - restart coord 1 and 2
> - drop node c2 from c1 and c1 from c2 and add them back followed by select
> pgxc_pool_reload();
>
> So I tried to create the same table T1 from Coord2 to observe behavior
> and it did not like it clearly as all nodes it "wrote" to reported that the
> table already existed which was good. At this point I could understand that
> Coord2 and Coord1 are not talking alright so I created a new table from
> coord1 with replication. This table was visible from both now.
>
> Question is should I expect to see the first table, let me call it T1
> after a while from Coord2 also?
>
>
> thanks,
> Shankar
>
>
>
>
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> Postgres-xc-developers mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>
>


-- 
Best Wishes,
Ashutosh Bapat
EntepriseDB Corporation
The Enterprise Postgres Company

On Fri, Jul 6, 2012 at 1:38 PM, Shankar Hariharan <
har...@ya...> wrote:

> Follow up to earlier email. In the setup described below, can I avoid
> using a gtm-proxy? That is, can I just simply point coordinators to the one
> gtm running on node 3 ?
> My initial plan was to just run the gtm on node 3 then I thought I could
> try a datanode without a local coordinator which was why I put these two
> together on node 3.
> thanks,
>
GTM proxy is not a mandatory element in an XC cluster.
So yes, you can connect directly a Coordinator or a Datanode to a GTM.
-- 
Michael Paquier
http://michael.otacoo.com

Follow up to earlier email. In the setup described below, can I avoid using a gtm-proxy? That is, can I just simply point coordinators to the one gtm running on node 3 ?
My initial plan was to just run the gtm on node 3 then I thought I could try a datanode without a local coordinator which was why I put these two together on node 3.
thanks,
Shankar


________________________________
 From: Shankar Hariharan <har...@ya...>
To: "pos...@li..." <pos...@li...> 
Sent: Thursday, July 5, 2012 11:35 PM
Subject: Question on multiple coordinators
 

Hello,

Am trying out XC 1.0 in the following configuraiton.
Node 1 - Coord1, Datanode1, gtm-proxy1
Node 2- Coord2, Datanode2, gtm-proxy2
Node 3- Datanode3, gtm

I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In addition I missed the pg_hba edit as well. So the first table T1 that I created for distribution from Coord1 was not "visible| from Coord2 but was on all the data nodes. 
I tried to get Coord2 backinto business in various ways but the first table I created refused to show up on Coord2 :
- edit pg_hba and add node on both coord1 and 2. Then run select pgxc_pool_reload();
- restart coord 1 and 2
- drop node c2 from c1 and c1 from c2 and add them back followed by select pgxc_pool_reload();

So I tried to create the same table T1 from Coord2 to observe behavior and it did not like it clearly as all nodes it "wrote" to reported that the table already existed which was good. At this point I could understand that Coord2 and Coord1 are not talking alright so I created a new table from coord1 with replication. This table was visible from both now. 

Question is should I expect to see the first table, let me call it T1 after a while from Coord2 also? 


thanks,
Shankar

Hello,

Am trying out XC 1.0 in the following configuraiton.
Node 1 - Coord1, Datanode1, gtm-proxy1
Node 2- Coord2, Datanode2, gtm-proxy2
Node 3- Datanode3, gtm

I setup all nodes but forgot to add Coord1 to Coord2 and vice versa. In addition I missed the pg_hba edit as well. So the first table T1 that I created for distribution from Coord1 was not "visible| from Coord2 but was on all the data nodes. 
I tried to get Coord2 backinto business in various ways but the first table I created refused to show up on Coord2 :
- edit pg_hba and add node on both coord1 and 2. Then run select pgxc_pool_reload();
- restart coord 1 and 2
- drop node c2 from c1 and c1 from c2 and add them back followed by select pgxc_pool_reload();

So I tried to create the same table T1 from Coord2 to observe behavior and it did not like it clearly as all nodes it "wrote" to reported that the table already existed which was good. At this point I could understand that Coord2 and Coord1 are not talking alright so I created a new table from coord1 with replication. This table was visible from both now. 

Question is should I expect to see the first table, let me call it T1 after a while from Coord2 also? 


thanks,
Shankar