[Postgres-xl-general] ALTER TABLE - ADD NODE

Aaron Jackson ajackson at revionics.com
Thu Sep 18 21:35:41 PDT 2014


For many reasons, you should ignore my previous email.  Obviously what I tried to do was add a datanode to a cluster in a live fashion - and the documentation clearly doesn't recommend doing that for adding a new datanode.

The bigger kicker here is that I actually added datanode4 with the same port as datanode1 - they're one digit off.  My mistake.

Aaron
________________________________
From: Aaron Jackson
Sent: Thursday, September 18, 2014 11:06 PM
To: postgres-xl-general at lists.sourceforge.net
Subject: ALTER TABLE - ADD NODE

So I added a datanode to my cluster this evening (more or less by hand for fear of it going sideways with pgxc_ctl).  The datanode was added to all coordinators and then to all other datanodes without any incident.  Then I did the following:

ALTER TABLE client.foo ADD NODE (datanode4);

Well, client.foo has about 60M rows in it so this took a while.  When I came back, I saw the following error on my screen.

ERROR:  tuple already updated by self

So, I decided to see if the table sizes on each node via an execute direct with each node.

devanalysis57=# execute direct on (datanode1) 'select count(*) from client.foo';
  count
----------
 21541902

devanalysis57=# execute direct on (datanode2) 'select count(*) from client.foo';
  count
----------
 21051824

devanalysis57=# execute direct on (datanode3) 'select count(*) from client.foo';
  count
----------
 17412700

devanalysis57=# execute direct on (datanode4) 'select count(*) from client.foo';
  count
----------
 21541902

I think it's a little too coincidental that datanode4 and datanode1 have the same number of entries.  I ran pgxc_pool_reload() on all nodes, so they should all be aware but to be sure, I checked pg_catalog.pgxc_node to be sure.

So, I then tried to drop datanode4 from client.foo which it didn't like very much.

ALTER TABLE client.foo delete node (datanode4);
ERROR:  PGXC Node datanode4: object not in relation node list

Aaron
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.postgres-xl.org/private.cgi/postgres-xl-general-postgres-xl.org/attachments/20140919/fdcd184d/attachment.htm>


More information about the postgres-xl-general mailing list