IDS Forum

RE: database replication setup help

Posted By: LARRY SORENSEN
Date: Thursday, 23 May 2013, at 2:05 p.m.

In Response To: database replication setup help (Justin Killen)

Along with what Art said, you would need to set up the sqlhosts file on all the servers involved so that they know about eachother. The services file on the two secondary servers also need to be set up similar to the primary.

If your secondary servers are intended to be read only, you can set up the servers as you suggest or have two HDR secondaries. One of the major differences that you will see is that the HDR secondary is guaranteed to be in sync, but may slow down transaction processing on the primary, slightly, depending upon your network. The RSS secondary could possibly be out of sync slightly since transactions on the primary are processed first and then sent to the RSS secondary. If you want the secondary servers to be exactly in sync at all times, you should have two HDR secondaries.

To have your applications at site1 still point to the primary, you just need the correct sqlhosts entries and your environment variables set up correctly. If your primary server goes down and you would like to promote a secondary, you just go through the process on that secondary to promote it, and then change your environment variables to point at it instead of the original primary.

I hope this helps.

Larry Sorensen

> To: ids@iiug.org
> From: jkillen@allamericanasphalt.com
> Subject: database replication setup help [30326]
> Date: Thu, 23 May 2013 13:31:24 -0400
>
> Hi.
>
> For the last several years, we've been running an Informix database for our
> accounting and production systems. We have two primary locations, which for
> the purpose of this email I'll call HQ and Site1. Site1 is connected to HQ
> over a WAN link (T1, etc), but we are investigating possible options to change
> this to use Informix's replication (mainly to speed up access). HQ and Site1
> both work on the same data sets, so in the event the line goes down, we would
> prefer Site1 be read-only to avoid any data conflicts. Additionally, we like
> to add redundancy in the HQ location to prevent down-time in the event of
> server hardware failure, etc.
>
> After some research and reading, here's what we've come up with:
>
> HQ location:
> 1 HDR primary server
> 1 HDR secondary server
>
> Site1:
> 1 RSS server (readonly)
>
> Does this sound reasonable?
> When a program is run from Site1, and an update/insert/delete statement is
> run, how do we set it up so that the statement gets sent up to the HQ primary
> transparently?
> I read that schema change propagation only happens in Flexible Grid and not in
> ER, so when a schema change is made on the HDR primary, does it automatically
> propagate down to the secondary and RSS servers? I'm a little confused about
> the difference between Flexible Grid and ER and how they work together.
>
> Thanks In Advance,
> -Justin
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>

Messages In This Thread

• database replication setup help
  Justin Killen -- Thursday, 23 May 2013, at 1:31 p.m.
  • Re: database replication setup help
    Art Kagel -- Thursday, 23 May 2013, at 1:52 p.m.
    • RE: database replication setup help
      Justin Killen -- Thursday, 23 May 2013, at 2:43 p.m.
      • Re: database replication setup help
        Art Kagel -- Thursday, 23 May 2013, at 2:55 p.m.
        • RE: database replication setup help
          Justin Killen -- Thursday, 23 May 2013, at 4:03 p.m.
          • Re: database replication setup help
            Art Kagel -- Thursday, 23 May 2013, at 4:18 p.m.
      • RE: database replication setup help
        Everett Mills -- Thursday, 23 May 2013, at 3:24 p.m.
  • RE: database replication setup help
    LARRY SORENSEN -- Thursday, 23 May 2013, at 2:05 p.m.
    • Re: database replication setup help
      Art Kagel -- Thursday, 23 May 2013, at 2:33 p.m.
  • Re: database replication setup help
    Madison Pruet -- Thursday, 23 May 2013, at 2:08 p.m.

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