APT_CONFIG_FILE

{
node “node1″
{
fastname “SVR1″
pools “”
resource disk “C:/IBM/InformationServer/Server/Datasets/Node1″ {pools “”}
resource scratchdisk “C:/IBM/InformationServer/Server/Scratch/Node1″ {pools “}
}
node “node2″
{
fastname “SVR1″
pools “”
resource disk “C:/IBM/InformationServer/Server/Datasets/Node1″ {pools “”}
resource scratchdisk “C:/IBM/InformationServer/Server/Scratch/Node1″ {pools “”}
}
node “node3″
{
fastname “SVR2″
pools “” “sort”
resource disk “C:/IBM/InformationServer/Server/Datasets/Node1″ {pools “”}
resource scratchdisk “C:/IBM/InformationServer/Server/Scratch/Node1″ {pools  ”" }
}

}

This is a 3 node configuration file. Lets go through the basic entries and what it represents.

Fastname – This refers to the node name on a fast network. From this we can imply that the nodes node1 and node2 are on the same physical node. However if we look at node3 we can see that it is on a different physical node (identified by SVR2). So basically in node1 and node2 , all the resources are shared. This means that the disk and scratch disk specified is actually shared between those two logical nodes. Node3 on the other hand has its own disk and scratch disk space.

Pools – Pools allow us to associate different processing nodes based on their functions and characteristics. So if you see an entry other  entry like “node0” or other reserved node pools like “sort”,”db2”,etc.. Then it means that this node is part of the specified pool.  A node will be by default associated to the default pool which is indicated by “”. Now if you look at node3 can see that this node is associated to the sort pool. This will ensure that that the sort stage will run only on nodes part of the sort pool.

Resource disk  - This will specify Specifies the location on your server where the processing node will write all the data set files. As you might know when Datastage creates a dataset, the file you see will not contain the actual data. The dataset file will actually point to the place where the actual data is stored. Now where the dataset data is stored is specified in this line.

Resource scratchdisk – The location of temporary files created during Datastage processes, like lookups and sorts will be specified here. If the node is part of the sort pool then the scratch disk can also be made part of the sort scratch disk pool. This will ensure that the temporary files created during sort are stored only in this location. If such a pool is not specified then Datastage determines if there are any scratch disk resources that belong to the default scratch disk pool on the nodes  that sort is specified to run on. If this is the case then this space will be used.