Re: Replication performance - how to measure it ?

From: DA Morgan <damorgan_at_psoug.org>
Date: Thu, 24 Aug 2006 16:27:02 -0700
Message-ID: <1156462022.36143@bubbleator.drizzle.com>

diesel wrote:

>> And if you don't have Books Online installed, here's a link to the
>> internet copy: http://msdn2.microsoft.com/en-us/library/ms152751.aspx
>>
>> --
>> Hugo Kornelis, SQL Server MVP

>
> Thanks for fast reply, guys.
> Hugo, thanks for the link about MS SQL Server monitoring :)
>
> DA Morgan&fitzjarrell, you're right. I'm sorry, my mistake.
> Oracle version is 10gR2 10.2.0.1.0, IBM DB2 v8.1.7
> and Microsoft product will be probably MS SQL Server 2005
>
> At present I've got configured replication only for DB2,
> as concerns Oracle - I'm working on it.
> Actually, I'm going to test almost all kinds of replication method
> offered by these RDBMS,
> so I need the most uniwersal benchmark&monitoring tool for this.

No such thing in the Oracle world. Different tools for different requirements and different modes depending on your priority.

The faster the replication the more risk of data being lost. Here's something to consider. Is the transaction completed when it is committed on the primary box or is it completed when it is committed both locally and at the replication site? What happens if the link between the two goes down? Do you continue local processing and hope to catch up later or do you stop all transactions? These are all very important questions.

To just be testing speed alone is sort of like the airplane pilot who cuts the engines at 35,000 feet and at 1,500 feet announces to the passengers that fuel economy is really improved.

> I know that it's hard to advice, but believe me that since a few days
> I'm just searching&looking for information about a software or
> procedure to evaluate replication performance.

And what I am cautioning you about is that replication performance is a meaningless metric unless you are comparing technologies that produce the same outcome. Not just when all is perfect but in real world situations. I can make anything really fast if I don't care what happens later when there is a network glitch.

> On usenet, ftp's, WWW, P2P, DBA forums, etc. well, just everywhere.
> But it seems, that not a lot of admins need to make a replication
> tests. Thats why I decided to ask for help here .
>
> Cheers,
> Mark

I hope you do help ... but I see no evidence that you are really trying to compare apples with apples. If you don't your will produce numbers. Meaningless numbers ... but numbers. I suspect that is not your goal.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org

Received on Thu Aug 24 2006 - 18:27:02 CDT