Clique/AMP Modeling - Parallel Upgrade Tool (PUT)

Parallel Upgrade Tool (PUT) Reference

Parallel Upgrade Tool (PUT)
Release Number
February 2020
English (United States)
Last Update
Product Category
Teradata Tools and Utilities

The Clique/AMP Modeling step determines what storage to use for Teradata pdisks, how to configure that storage, and the optimal number of AMP vprocs to define for the storage. Recommendations are presented in a system summary screen where modifications can be made if necessary. For systems running Teradata Database release V2R5 or later, you can also define Hot Standby nodes.

Designate Hot Standby Nodes

The Designate Hot Standby Nodes screen opens when you select Support Hot Standby Nodes on the Set Defaults screen, which is only available for systems running Teradata Database release V2R5 or later or when your platform family is in the 1000 or 6000 series. This screen is skipped for systems running earlier versions of Teradata Database, whether the Support Hot Standby Nodes options is selected or not.

For Teradata Database release 14.0 or later, you can designate a node as Persistent Hot Standby. Persistent Hot Standby nodes are kept in the configuration indefinitely, to avoid unneeded AMP movement.

For Teradata Database release 13.10 or earlier, the left side of the screen lists all TPA nodes present in the system; the right side lists the nodes currently defined as Hot Standby. A Hot Standby Node is one that is reserved for use as a backup node in case a TPA node fails. Hot Standby nodes can be defined only for multi-node cliques.

For Teradata Database release 14.0 or later, the screen contains three columns: TPA nodes present in the system on the left; nodes currently defined as Hot Standby in the middle; and Persistent Hot Standby nodes on the right.

To designate a node as either TPA, Hot Standby or Persistent Hot Standby, select it and click the arrow buttons to move them from one list to the other. The default Hot Standby node is the node with the highest node-id within each clique.

If you do not want to define any Hot Standby nodes, move all the nodes to the TPA list and click Next to move on to the next process.

Clique/AMP Summary Screen

The Clique/AMP Summary screen displays a summary of the AMP and storage selections for each clique in the system. Cliques are summarized into "groups." A group is the set of cliques that share the same number of nodes, CPUs per node, amount of memory, and storage characteristics. Within a group, each clique is displayed with the node-ids for that clique along with the number of existing AMPs, new AMPs, and total number of LUNs selected for AMP pdisks.

Clique/Amp Summary screen

The initial display shows the current system configuration (if any) as well as PUT recommendations for new AMPs and storage (if any). Examine the information on the screen, and if no changes are necessary, click Next to continue to the next process.

To display detailed information about the storage and AMPs selected for a particular clique, or to modify the selections, double-click the clique’s folder icon to open the Clique Details screen.

How Does PUT Determine Its Recommendations?

PUT determines the system model for each node in each clique in the system and assigns a performance rating to the clique. Next, PUT looks at the amount of real memory available for AMP vprocs on each clique to establish and recommend the maximum number of AMPs for each clique.

The system model characteristics and AMP memory requirement constants are stored in the CliqueModInfo.txt file in the TDput/data/permanent directory.

PUT then scans the performance data for all cliques in the system and identifies the clique with the lowest performance rating and least amount of memory available. This is considered to be the "base clique." PUT determines the recommended number of AMPs for the base clique by examining the storage available for use as AMP pdisks in this clique and choosing an optimal mix of AMPs to match it. In some cases, PUT may recommend leaving some storage unused in order to ensure a balanced clique where each AMP has the same amount of storage available and each node has the same number of AMPs assigned. Once the recommendations have been built for the base clique, the process is repeated for each of the remaining cliques with one additional restriction: the remaining cliques are now constrained by the AMPs and storage assigned to the base clique. This means that the recommendations for all remaining cliques are relative to the recommended numbers for the base clique. This is PUT’s attempt to construct a system that is balanced both within each clique and across all cliques.

When calculating the proper number of AMPs for a multi-node clique, PUT chooses a number such that if one node fails in the clique, the remaining nodes have sufficient resources to pick up the migrating AMPs from the failed node and continue running. PUT may therefore recommend fewer AMPs than expected at times. If the clique has one or more Hot Standby nodes defined, PUT skips this added constraint and assumes the Hot Standby nodes are sufficient to handle node failures within the clique. Hot Standby nodes are not counted during PUT's performance evaluation of the clique since they do not participate as TPA nodes except during a node failure.

Clique Details Screen

The Clique details screen opens when you double-click a clique folder on the Clique/Amp Summary screen. The number of new AMPs to be created for this clique are shown along with the storage selected for use. It also displays any storage to be excluded from the configuration. Storage is displayed by type (NS, EMC, or JBOD), disk array name or serial number, LUN number, and partition or slice. Note that the number of existing AMPs is not displayed on this screen - only the number of new AMPs.

When the storage trees are expanded, storage already assigned to existing AMPs is displayed in red and cannot be modified. Recommended storage for new AMPs is displayed in blue. Storage displayed in black is excluded.

You can update the number of new AMPs and the storage to be selected or excluded (with the exception of storage already assigned to existing AMPs). To modify the number of new AMPs to define, enter the number of AMPs desired in the Number of new AMP vprocs to create box. Note that there is always a relationship between the number of AMPs to create and the amount of storage pieces selected. Always make sure that you have enough storage selected to satisfy the number of AMPs requested; if insufficient storage is selected an error appears.

Move the storage pieces from and to the Selected and Excluded lists using the drag-and-drop method. You can select multiple items and move them all at the same time. You can also move an entire array, or all parts of a LUN, by dragging the array or LUN to the desired list. When you move an array or LUN, all associated storage moves at the same time.

Storage in the Selected list is used by PUT in the best way possible. You can force PUT to use additional storage by moving storage from the Excluded list to the Selected list. Once you click Next, whatever storage is in the Selected list becomes the final list of storage used for the clique. PUT then allocates that storage based on the number of AMPs selected.

Excluded storage is recorded in the excluded_storage.txt file. This file is written to all TPA nodes and is stored in the TDput/data/permanent directory. Once stored in the excluded_storage.txt file, storage is considered permanently excluded from the configuration and is not seen by PUT again until it is removed from this file or the file is deleted from all TPA nodes.

Clique Details screen

The lower portion of the Clique details screen contains four buttons:
Button Action:
Save Changes Saves updates and sends them to the PUT sequencer for processing. If you try to close the window without committing the changes, PUT asks if you want to save the changes. Additional changes can be made after you save current changes.
Discard Unsaved Changes Discards changes if they have not been saved yet.
Restore Initial Display Discards all changes and returns to the initial configuration display.
Close Returns the display to the main summary screen.

Unpartitioned Storage

PUT usually creates one partition per LUN by default. However, the exact number depends on the specific platform family selected.

Verify the number of partitions to be created by expanding the list of LUNs in the Partition LUN tree (which can be accessed from the Partition LUN step of the PUT operation). If necessary, you can override this number on a per-LUN basis.

Error Messages and Warnings

Error Message Description
Clique shared storage error detected This message indicates that at least one node shares only some of the storage devices in the clique. The display shows the two nodes in conflict. Under each node is a list of shared disk controller serial numbers accessible from that node. The lists must be identical for both nodes to be in the same clique.

This is a fatal error and must be corrected before the Configure Teradata Vantage sequence can run successfully. Locate the LUN in conflict and make sure it is visible to the operating system on all nodes in the clique, or remove it from all but one node so it is not included as available clique storage.

CliqueAmpMod determined this is a re-config, but no previous GDO information can be found This message indicates that the GDO Info step found previous configuration information, but the SysMerge step cannot access the internal tables that contain the previous configuration data. This is a fatal error and the step aborts to prevent any possibility of overwriting an existing configuration with a new one.
Configure Teradata Vantage cannot match previously-defined pdisks with current storage. Configure Teradata Vantage cannot continue This message indicates that CliqueAmpMod cannot find previously defined pdisks within the current system storage devices. This is a fatal error. CliqueAmpMod does not continue because to do so would risk losing existing data.
One or more ACTIVE AMP vprocs were found to have pdisks spread across multiple cliques. All pdisks assigned to an AMP must be in the same clique This message indicates that the pdisks for an AMP are currently on devices in different cliques. This is an invalid system configuration. All storage for a single AMP must physically reside in the same clique as the AMP. Because the AMP is currently active, this is a fatal error and must be corrected before Configure Teradata Vantage can run successfully.
CliqueAmpMod has detected an empty storage table. This means that no available storage space was found and no existing Teradata pdisks were found This message indicates there is no available disk storage on the system and there is no existing database. You cannot create a valid Teradata configuration without at least one piece of disk storage. This is a fatal error.
Error defining Hot Standby Nodes This error indicates the nodes selected cannot be configured as Hot Standby nodes. This can occur if you try to select all nodes in a clique to be Hot Standby nodes. There must always be at least one node defined as a TPA node in each clique. This error can also occur if you try to select a node that already has assigned AMP vprocs. In this case use Configure Teradata Vantage to re-assign the AMPs to another node in the clique. Then run Configure Teradata Vantage again and select this node to be a Hot Standby node.
No Storage Selected for Clique This error appears if one or more cliques with no storage are selected for use as pdisks. Each clique in the display must have some storage selected - either already used for existing AMPs or storage intended for use in new AMPs. By definition, each clique must have at least one AMP and each AMP must have at least one pdisk.
No AMP vprocs specified for clique This error appears if you have one or more cliques with no AMPs specified. Each clique must have at least one AMP and each AMP must have at least one pdisk.
Clique does not have enough pdisks This error indicates that more AMPs than the number of selected storage pieces for the clique have been selected. Since the storage is already partitioned, PUT must use it as is, but there are not enough storage pieces selected to assign pdisks to the number of AMPs specified.
Warning - possible configuration errors detected This message indicates that the cliques listed either have too many AMPs defined compared to the rest of the system, or too much storage, or both. This message is a warning only. PUT considers any number of AMPs beyond its recommendations to be "excess." If the number of AMPs specified is correct, ignore this warning.

The excess storage condition occurs when the amount of storage selected would cause the associated AMPs to have more storage capacity than the rest of the AMPs in the system. In this case, the excess capacity is ignored by Teradata and essentially wasted. Sometimes this condition is unavoidable, depending on the mix of storage types in the system. Ignore this warning and continue with the configuration as selected.