The Define Clustering step creates the cluster definitions for the AMP vprocs in the current Teradata configuration. AMPs can be assigned to their default clusters automatically, or you can create your own custom cluster assignments by running the Configure Teradata Vantage operation in Custom configuration mode.
It is strongly recommended that you use the PUT default cluster assignments unless you are an experienced Teradata system administrator.
This step runs after the new vconfig.gdo file has been created.
Define Clustering in Typical Mode
In Typical configuration mode, once the cluster definitions have been generated, the Define Clustering step is complete and operation continues with the next step. An exception to this is when new AMP vprocs have been added to an existing system using non-standard clustering definitions. In this case, PUT cannot automatically assign the new AMPs to clusters because it does not have the formula used to set up the original clustering. As a result, PUT displays the clustering screen with a list of all the current cluster definitions and the new AMPs are listed as "unassigned." You are responsible for assigning the new AMPs to their proper clusters. Follow the instructions in "Define Clustering in Custom Mode" to assign new AMPs.
Define Clustering in Custom Mode
In Custom configuration mode, the current clustering definitions are listed (either based on the PUT defaults or the previous assignments) and you can update the cluster assignments as needed. AMP vprocs that have been created during the current session of Configure Teradata Vantage (for example, "new" AMPs) are indicated with an "*" in front of their ids.
Option | Action |
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Display cluster assignments | Double-click either the cluster name or its icon to display the cluster assignments. AMPs are shown immediately under their assigned cluster number. |
Assign (or move) an AMP vproc to a specific cluster | Click and drag an AMP vproc from the right pane and drop it on the desired cluster number in the left pane. You can select and move one or more AMPs at a time. |
Reset current clustering and generate all PUT standard cluster assignments | At any time while the screen is open, discard the current clustering and have PUT re-generate its default clustering by clicking Reset current clustering and generate all PUT standard cluster assignments at the top of the screen and then clicking Next. The current cluster assignments are discarded and PUT generates new cluster definitions for the complete configuration based on the algorithm described in "How AMPs-per-cluster are Calculated." |
Save the cluster assignments | The clustering assignments made during this step are only saved during Config/Reconfig when PUT starts the database. If you choose to not have PUT start the database at the end of the operation, any clustering assignments made during this session are lost and you will have to re-do them the next time Configure Teradata Vantage is performed. As long as you choose to have PUT start the database, PUT issues the appropriate clustering commands and the cluster assignments are retained. |
Define Clustering Rules
- AMP vprocs are not allowed to remain in the unassigned list when you click Next. All AMP vprocs must be assigned to a cluster number before the clustering can be completed.
- Cluster assignments must always start with cluster number 0 and continue sequentially. You cannot leave an empty cluster between two clusters that have AMP vprocs assigned to them.
- PUT always displays the entire list of the maximum clusters allowed (total AMPs / 2). You can use as few or as many clusters as you like (following the rules above). When you have completed the cluster assignments, any remaining empty clusters are ignored and only the clusters with AMP vprocs assigned are retained.
- The default cluster size for new systems is set to 2. If clustering on an existing system was generated by PUT, new AMPs are clustered using the same method. If the current clustering is not the PUT default, new AMPs must be clustered by the user.
Define Clustering Operational Messages
Message | Description |
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One or more AMP vprocs have not been assigned to a cluster | This message indicates there are still AMP vprocs in the unassigned list. You cannot click Next until all AMP vprocs have been moved from the unassigned list to a cluster number. |
There are one or more unused clusters between cluster X and cluster Y | This message indicates you have left an empty cluster between two assigned clusters. This is an error. Any empty clusters must always be the last (for example, highest) clusters in the list. Cluster assignments must always start with cluster 0 and continue through sequential cluster numbers until all AMPs have been assigned. You must assign AMP vprocs to the unused cluster(s) between the cluster numbers indicated on this message. |
Cluster 0 is unused | This message indicates you have left cluster 0 with no AMP vprocs assigned to it. Since cluster assignments must always start with cluster 0, this is an error. You must assign AMP vprocs to cluster 0 and continue through sequential cluster numbers until all AMPs have been assigned. |