Re: [Postgres-xc-general] Install postgres-xc on redhat

[Joseph M. <ma...@wi...>]

Thanks for your help! I did a dumpall out of the existing server and loaded it into the new “cluster”. It seemed to work fine, but I did not get this message until after, so I did not add any “Distribute By” statements to the CREATE TABLE commands. I will have to do the import again before turning up the server for real. I will try to do this on the next important.

My last two questions are about adding a server to the cluster, and startup commands.

First off, after I get the first server running as a clustered machine, I will be transferring all our sql client software over to it. Then I will be taking what was the original, reconfiguring it to be another machine in the cluster, and adding it to the cluster for a two-machine cluster.

Unless I am looking in the wrong place I have found very little info on how to add a machine to the cluster. Everything seems to assume that all the machines in the cluster are being created together. Does anyone know where I can find info on adding a machine, including configuring the second machine, adding it so it talks to the other, bring the databases into sync with each other, etc.?

Lastly, I am running under redhat, and I haven’t found anything about how to set up the software to start under chkconfig. It’s tricky, especially since you have 3 daemons to start (gtm, postgres datanode, and postgres coord) and I believe it matters what order they are started in.

From: Mason Sharp 
Sent: Monday, August 11, 2014 4:45 PM
To: Joseph Mays 
Subject: Re: [Postgres-xc-general] Install postgres-xc on redhat

Hi Joseph,




On Wed, Aug 6, 2014 at 4:47 PM, Joseph Mays <ma...@wi...> wrote:

  I did several searches of the entire file system for it, to no avail. I finally downloaded the source to 1.0.4 and built the binaries from the source code and installed, and initgtm as well as the other pieces are there now.

  What I am trying to do is turned a what was a slaved streaming backup of another pgsql server into a server in a postgres-xc cluster. When I have it operational, and have the database running on it, I’ll point things at it instead of the primary, then make what used to be the primary into a second server in this cluster.

  So, I a couple of questions. Is there any problem with using databases created under a standard postgres server on a postgres-xc cluster?

You would have to export it and then import it into Postgres-XC (or Postgres-XL).  You should spend some time on your CREATE TABLE statements to add the appropriate DISTRIBUTE BY clause; it may make a big difference in performance.


  Also it says gtm should not be run on the same server with the other components. Is this correct? 

You should be fine running it together if the number of servers is small and it meets your performance requirements.

  I have only two servers here, and I assumed I was going to be running gtm, as well as the other software, on both, so either could function as the primary or secondary at will. Is this a problem?

You can do that-- have datanode masters on server 1 and server 2, have server 1's datanode slave(s) on server 2, and vice versa.

Good luck!

-- 

Mason Sharp

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