Admin Pools
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[edit] IV. Pools
The Cluster Admin of a cluster decides whether or not that cluster will contribute resources to the default pool at the Grid Portal. Additionally, the cluster can join specialty pools on the Grid and contribute resources there as well. Resources contributed consist of: compute cycles and applications. Only jobs that run applications can be run in pools.
The Cluster Admin is responsible for setting up the scheduler queues so that Pool Jobs do not take more resources than have been allocated for them. At any given cluster, all pool jobs run under a single Pool Guest User.
[edit] A. Pool Guest User
The Pool Guest User must:
- Have a real login id on the cluster and have a home directory there.
- Be Grid-Enabled and set up for the Grid Portal in the normal way.
- Not actually be able to login to the Grid Portal.
The Cluster Admin and the Grid Admin will have to work cooperatively on these tasks.
[edit] Create the Pool Guest User
The Cluster Admin can create the Pool Guest User as follows:
1. As root on the cluster head node, create the login id and assign a home directory to it via the useradd command. For example:
useradd -c 'POOL USER' -u uid -g gid -s /bin/bash -d homedirectory -M
pooluser
2. Go to the Grid Portal's home page and click Apply for Grid Access and go through the workflow in the normal way including Grid-Enabling the user.
After the Grid Admin clicks on Approve during his/her part of the workflow process, he/she should additionally follow the instructions given in the section on Users in this document to disable the user. This will prevent anyone from logging in to the Grid Portal as the guest user. Pool jobs can then be run under the Pool Guest User's Username/cluster login id but that Username cannot be used for any other purpose.
[edit] Configure the Grid Portal to Submits Pool Jobs for a Particular Cluster as the Pool Guest User Created for that Purpose
The Grid Admin has to configure the Grid Portal so that it submits pool jobs to the cluster as the Pool Guest User just created for the cluster. To do so, the Grid Admin has to login to the Grid Portal machine as user globus and edit the file:
UCLAGridPortal/Portal/config/pool.xml
After modifying the file, the Grid Admin has to redeploy UGP by entering:
cd UCLAGridPortal/Portal ant deploy
To add cluster resources to a Grid Portal, look for the the "DefaultGrid" section of the pool.xml file. This is where the information about Pool Guest Users and the clusters contributing pool resources is provided to the Grid Portal. It will look something like this:
<grid-pool name="DefaultGrid">
<pool-account>
<pool-cluster>ga1.abcd.edu</pool-cluster>
<pool-home>/u/home3</pool-home>
<pool-scheduler>SGE</pool-scheduler>
<pool-myproxy>myproxy.abcd.org</pool-myproxy>
<pooluser username="poolguest" password="guestpass" />
</pool-account>
<pool-account>
<pool-cluster>ga2.abcd.edu</pool-cluster>
<pool-home>/u/home3</pool-home>
<pool-scheduler>SGE</pool-scheduler>
<pool-myproxy>myproxy.abcd.org</pool-myproxy>
<pooluser username="guest01" password="47a963bol843s" />
</pool-account>
</grid-pool>
In the example above, two clusters are providing pool resources. To add an additional cluster, duplicate the lines starting with the pool-account opening tag and ending with the pool-account closing tag and modify the fields as follows:
pool-cluster
Enter the address of the Grid Appliance attached to the cluster that is
contributing resources.
pool-home
Enter the path to the user home directories on that cluster.
pool-scheduler
Enter the scheduler used by this cluster, either: SGE or PBS. If you
are using Torque, enter PBS.
pool-myproxy
Enter the address of the MyProxy Server containing the proxy
certificate for the Pool Guest User.
pooluser
Enter the Grid Portal Username and Password of the Pool Guest User.
[edit] Manage Resources for the Pool Guest User at the Cluster Level
On the cluster, the Cluster Admin can up the scheduler to limit the resources that the Pool Guest User can consume. For example, if the cluster is contributing 20 percent of its cycles to the pool, then the Pool Guest User should not be able to use more than that.
Using SGE, the simplest method of control is to use consumable resources. In this approach, you limit maximum number of jobs that can be run at the same time on the cluster by a specific user, in this case the Pool Guest User, to a fixed number. Whenever this many Pool Guest User jobs are running all other Pool Guest User jobs will wait in the queue until one of the running Pool Guest Users jobs finishes.
The other means of restricting resources invlolve policy configurations. The two kinds of policies that are available in SGE 6.0 are called Shared Tree policy and Functional policy. Functional policies allow users, per departments, projects, or jobs to allocate resource percentages. Please refer to the SGE 6.0 documentation for an explanation of how to create projects and allocate resources through the qmon GUI.
If you are using a scheduler other than SGE, refer to the documentation for your scheduler for how resource use can be limited.
[edit] B. Pools and Applications
Every Grid Portal that includes support for pools must have a Default Pool. Every user, whether a Cluster User or a Pool-Only User, has access to the Default Pool. In addition to the Default Pool, you can set up specialty pools.
[edit] Set up the Default Pool
1. Login to the Grid Portal as the Grid Admin.
2. Go to Pool Admin under Grid Admin.
3. Click on the Add button. Create a Pool and name it something like UCLA Default Pool, replacing UCLA with whatever your Grid is. Give the Grid Admin's email address and check that the pool is the default pool and local only. For the Storage Server enter the address of the Storage Server at your Grid Portal.
4. Click on the Save button.
[edit] Associate Applications with the Default Pool
Before you can associate applications with the Default Pool you must configure those applications. Follow the instructions in the section titled Applications in this document.
Now associate the applications that can be run by pool users with the Default Pool. Go to Application Pool under the Grid Admin tab. On that page, the pull down menu labeled Application Name is a list of the Display Names of all the applications on every cluster in the Grid.
1. Select the application you want to add to the Default Pool and click on the Load Application List button.
2. You will see a list of all the unique names of this application on every cluster in the Grid which has it. Click on the one you want to add to the Default Pool and then on the Update button. The application will be associated with the pool.
[edit] Create Specialty Pools and Associate Applications with them
Follow the instructions above to add a new pool and associate applications with it whenever a group of Cluster Admins want to join together to create a new pool.
