Warning message from Teradata Enterprise stage on read

bcarlson · Post by **bcarlson** » Thu Mar 31, 2005 5:39 pm

We have been using DS with DB2 for a long time and are now starting to use Teradata.

I just created a simple program to test connectivity from our Teradata database. It is a read, using the Teradata Enterprise stage, to a dataset.

I can read the table okay, but get the following warning in the log:

Teradata_Enterprise_0: There will be some skew in the usage of the server because the number of players (3) is not evenly divided by the number of available nodes (8). [terareadop.C:439]

Our system:
Unix - IBM AIX 5.21on a P650
Database - Teradata V2R5.1, 1 physical node with 8 amps

ray.wurlod · Post by **ray.wurlod** » Fri Apr 01, 2005 6:53 am

This really belongs on the parallel forum.

The message is clear; it's alerting you to the fact that, because of choices you made (that is, to use three players), some players will be handling a greater workload than others.

To get an even workload from eight nodes, specify a whole divisor of 8 (for example 2 or 4) rather than three.

bcarlson · Post by **bcarlson** » Fri Apr 01, 2005 10:35 am

Sorry about the server vs. parallel forum, didn't realize where my message was being posted. Is it possible to move the posting?

As for the player config, how do I specify how many players to use?

We use DB2 and DataStage a lot, and I know that we have a configuration that was setup the described the DB2 environment. However, when I looked at the documentation on using Teradata with DataStage, I couldn't find any information about configuration. Is this documented somewhere and I just missed it?

ArndW · Post by **ArndW** » Fri Apr 01, 2005 10:42 am

The $APT_CONFIG_FILE specifies your node information, and detailed information is in the documentation, I would suggest starting on page 43 of the Parallel Job Developer's guide and progressing from there.

bcarlson · Post by **bcarlson** » Fri Apr 01, 2005 1:27 pm

How is the number of players related to the number of nodes? We have a number of different config files with node definitions ranging between 8 and 12 nodes. Here's a sample:

{
node "myserver" {
fastname "myserver"
pool ""
resource disk "/mydir/DataStage_work/1" {}
resource scratchdisk "/mydir/DataStage_scratch/1" {}
}
node "myserver-2" {
fastname "myserver"
pool ""
resource disk "/mydir/DataStage_work/2" {}
resource scratchdisk "/mydir/DataStage_scratch/2" {}
}

... etc., etc.,
node "myserver-8" {
fastname "myserver"
pool ""
resource disk "/mydir/DataStage_work/3" {}
resource scratchdisk "/mydir/DataStage_scratch/3" {}
}
}

So we have more than 3 nodes defined, but only 3 players are being used. No matter which configuration I use, only 3 players are used and I get the same warning everytime.

I've looked at the documentation (both the PJob and Mngr) before and again now, but I don't see what I am missing. And unfortunately, there isn't anything Teradata-specific in the config file docs.