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To add an interior node under the selected node, click Add Node. A blank Node Info window appears, where you can enter the node's name and number of shares. You can enter any node name or share number.

To add a leaf node under the selected node, click Add Leaf. A blank Node Info window appears, where you can enter the node's name and number of shares. The node's name must be an existing grid engine user (Configuring User Objects With QMON) or project (Defining Projects)

The following rules apply when you are adding a leaf node:

  • All nodes have a unique path in share tree.

  • A project is not referenced more than once in share tree.

  • A user appears only once in a project subtree.

  • A user appears only once outside of a project subtree.

  • A user does not appear as a nonleaf node.

  • All leaf nodes in a project subtree reference a known user or the reserved name default. See a detailed description of this special user in About the Special User default.

  • Project subtrees do not have subprojects.

  • All leaf nodes not in a project subtree reference a known user or known project.

  • All user leaf nodes in a project subtree have access to the project.

To edit the selected node, click Modify. A Node Info window appears. The window displays the mode's name and its number of shares.

To cut or copy the selected node to a buffer, click Cut or Copy. To Paste under the selected node the contents of the most recently cut or copied node, click Paste.

To delete the selected node and all its descendents, click Delete.

To clear the entire share-tree hierarchy, click Clear Usage. Clear the hierarchy when the share-based policy is aligned to a budget and needs to start from scratch at the beginning of each budget term. The Clear Usage facility also is handy when setting up or modifying test N1 Grid Engine 6 software environments.

QMON periodically updates the information displayed in the Share Tree Policy dialog box. Click Refresh to force the display to refresh immediately.

To save all the node changes that you make, click Apply. To close the dialog box without saving changes, click Done.

To search the share tree for a node name, click Find, and then type a search string. Node names are indicated which begin with the case sensitive search string. Click Find Next to find the next occurrence of the search string.

Click Help to open the online help system.

Share Tree Policy Parameters

To display the Share Tree Policy Parameters, click the arrow at the right of the Node Attributes.

  • CPU [%] slider -- This slider's setting indicates what percentage of Combined Usage CPU is. When you change this slider, the MEM and I/O sliders change to compensate for the change in CPU percentage.

  • MEM [%] slider -- This slider's setting indicates what percentage of Combined Usage memory is. When you change this slider, the CPU and I/O sliders change to compensate for the change in MEM percentage.

  • I/O [%] slider -- This slider's setting indicates what percentage of Combined Usage I/O is. When you change this slider, the CPU and MEM sliders change to compensate for the change in I/O percentage.


    Note - CPU [%], MEM [%], and I/O [%] always add up to 100%


  • Lock Symbol -- When a lock is open, the slider that it guards can change freely. The slider can change either because the slider was moved or because it is compensating for another slider's being moved.

    When a lock is closed, the slider that it guards cannot change. If two locks are closed and one lock is open, no sliders can be changed.

  • Half-life -- Use this field to specify the half-life for usage. Usage is decayed during each scheduling interval so that any particular contribution to accumulated usage has half the value after a duration of half-life.

  • Days/Hours selection menu -- Select whether half-life is to be measured in days or hours.

  • Compensation Factor -- This field accepts a positive integer for the compensation factor. Reasonable values are in the range between 2 and 10.

    The actual usage of a user or project can be far below its targeted usage. The compensation factor prevents such users or projects from dominating resources when they first get those resources. See Compensation Factor for more information.

About the Special User default

You can use the special user default to reduce the amount of share-tree maintenance for sites with many users. Under the share-tree policy, a job's priority is determined based on the node the job maps to in the share tree. Users who are not explicitly named in the share tree are mapped to the default node, if it exists.

The specification of a single default node allows for a simple share tree to be created. Such a share tree makes user-based fair sharing possible.

You can use the default user also in cases where the same share entitlement is assigned to most users. Same share entitlement is also known as equal share scheduling.

The default user configures all user entries under the default node, giving the same share amount to each user. Each user who submits jobs receives the same share entitlement as that configured for the default user. To activate the facility for a particular user, you must add this user to the list of grid engine users.

The share tree displays "virtual" nodes for all users who are mapped to the default node. The display of virtual nodes enables you to examine the usage and the fair-share scheduling parameters for users who are mapped to the default node.

You can also use the default user for "hybrid" share trees, where users are subordinated under projects in the share tree. The default user can be a leaf node under a project node.

The short-term entitlements of users vary according to differences in the amount of resources that the users consume. However, long-term entitlements of users remain the same.

You might want to assign lower or higher entitlements to some users while maintaining the same long-term entitlement for all other users. To do so, configure a share tree with individual user entries next to the default user for those users with special entitlements.

In Example A, all users submitting to Project A get equal long-term entitlements. The users submitting to Project B only contribute to the accumulated resource consumption of Project B. Entitlements of Project B users are not managed.

Example 5-2 Example A

Diagram shows project nodes A and B. Project A has the default
user as a leaf node. Project B has no leaf nodes.

Compare Example A with Example B:

Example 5-3 Example B

Diagram shows project nodes A and B. Project A has the default
user as a leaf node. Project B has three leaf nodes: default, and Users A and B.

In Example B, treatment for Project A is the same as for Example A. But all default users who submit jobs to Project B, except users A and B, receive equal long-term resource entitlements. Default users have 20 shares. User A, with 10 shares, receives half the entitlement of the default users. User B, with 40 shares, receives twice the entitlement as the default users.

Configuring the Share-Based Policy From the Command Line


Note - Use QMON to configure the share tree policy, because a hierarchical tree is well-suited for graphical display and for editing. However, if you need to integrate share tree modifications in shell scripts, for example, you can use the qconf command and its options.


To configure the share-based policy from the command line, use the qconf command with appropriate options.

  • The qconf options -astree, -mstree, -dstree, and -sstree, enable you to do the following:

    • Add a new share tree

    • Modify an existing share tree

    • Delete a share tree

    • Display the share tree configuration

    See the qconf(1) man page for details about these options. The share_tree(5) man page contains a description of the format of the share tree configuration.

  • The -astnode, -mstnode, -dstnode, and -sstnode options do not address the entire share tree, but only a single node. The node is referenced as path through all parent nodes down the share tree, similar to a directory path. The options enable you to add, modify, delete, and display a node. The information contained in a node includes its name and the attached shares.

  • The weighting of the usage parameters CPU, memory, and I/O are contained in the scheduler configuration as usage_weight. The weighting of the half-life is contained in the scheduler configuration as halftime. The compensation factor is contained in the scheduler configuration as compensation_factor. You can access the scheduler configuration from the command line by using the -msconf and the -ssconf options of qconf. See the sched_conf(5) man page for details about the format.

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