Sponsors Data

The hierarchical text files under the directory /software/accounts-master/data/sponsors on the machine cs-xh-admin.cs.private.uwaterloo.ca are a means to describe resources which should be allocated to users on various other machines. Computer programs are used to update remote machines to reflect the information there.

History

The system was designed by MFCF to facilitate charging real money for resources, and is based heavily upon the concept that all resources must have a sponsor (although sponsors do not need to provide real money, nor do sponsors even need to correspond to identifiable people). A long-time maintainer wrote an overview.

Overview

The text files can loosely be thought of as a database. In other respects their contents are really a configuration language, approaching the complexity (although not the generalized power) of a programming language. In fact, they are configuration files which are used to generate a text file database under the corresponding /software/accounts-master/data/resources directory. Those files are text tables, with identifiable fields or columns, but are not in normal relational form because some of the fields contain lists containing an arbitrary number of multiple values.

Furthermore, in fact, there is data embodied in the sponsors data which is not reflected in any particular version of the generated resource data. Resources can have start and end ("expiration") dates which are not present in the generated data; shown by SponsorshipEnds and MembershipEnds (also corresponding Starts). In the internal model used by several programs, sponsor_resources among them, an End date is recorded internally, corresponding to SponsorshipEnds (similarly for SponsorshipStarts, MembershipStarts and MembershipEnds), but those dates are not shown in any output.

So a "proper" database representation of resources embodied in the sponsors data might include all start and end dates, listing some resource data which is not in effect on the current day.

The author is beginning to conclude the sponsors data is not a database, but, rather, a configuration language to generate a database state corresponding to resource allocation desired for any particular day.

Leaving aside the quibble about what is a database, people sometimes refer to these files (either sponsors or resources directory) as the accounts database but computer accounts (working login names for particular computer systems) are created only as a side-effect of sponsorship. Furthermore, those accounts are only one type of resource which can be controlled by these files.

The types of resources which can currently be allocated are Computing, Printing, and MailAlias.

When doing actual accounts maintenance, it is usually the Computing type of resource we will be dealing with. But allocating Printing quota, or even setting up a MailAlias can be considered accounts maintenance too.

Historically ppp(dialin) access was maintained as a separate type, and there appears to be under development some attempt to incorporate some sort of maintenance of a licence resource, but those are currently irrelevant.

Computing resources will generate login userids for some computer system; currently CSCF generates login userids for either a specific UNIX system (which can be the NFS server for a region of related machines), or a Active Directory domain. For historical reasons, the Active Directory domains are referred to by the names of specific servers.

Resources which trigger the generation of login userids are actually of type Quota or Groups. If the sponsors database indicates that some valid login userid should receive (disk) Quota, or be made a member of some Group on some controlled system, that will cause the corresponding login userid to be created on that system, if it did not already exist.

Resource allocation or removal can be configured ahead of time by the use of Start and End dates. System configuration on the controlled machines will define how soon after sponsorship ends an account will actually be removed. This cannot be modified by users who can otherwise modify the sponsors data. In fact, it's even difficult for them to determine. When an account is no longer sponsored, but has not been removed, the sponsors data software considered it to be already "Expired", but "in grace period". This terminology can be confusing.

A similar confusion can occur because other system configuration on the controlled machines will define a base quota for all users. On some systems, this is so huge that most users are typically given zero quota. This base quota similarly cannot be modified and is difficult to determine for users who can otherwise modify the sponsors data.

As an example, perhaps see this attempt at an explanation of how the data is organized on host cs-xh-admin.cs.private.uwaterloo.ca.

Strengths and Weaknesses

The system's forté is assigning lots of similar resources to large groups of users based on userid (user name) and student id (number) and course or program registration as received from the registrar. In contrast, the system does not readily provide means for mass maintenance of information about users whose resource needs are otherwise arbitrarily varied. Note, however, that the fact the sponsors data is composed purely of text files does allow arbitrary tools to be used when massive changes are required.

Philosophy

The system is not really designed to make the creation of computer accounts an easy task. Rather, it is designed to make it difficult to allocate resources without creating an audit trail for those resources. Even without any special software, allocation of resources on computer systems tends to be naturally relatively easy. But several years later it can be difficult to tell why those resources were allocated and whether their allocation is still legitimate. The extra pain the sponsors database requires to attribute resource requests to sponsors can help solve that future problem, and allow the reclamation of resources whose allocation has become unjustified. And that said, the sponsors database does make some aspects of resource allocation easy, as a few lines of configuration can cause the allocation of hundreds of computer logins (or other resources) across several machines.

Omissions

The sponsors data can contain lots of information specific to classes which is not used in the generation of computer accounts. The documentation here largely ignores that; it is really only relevant for RegistrarSponsoredAccounts, and, even then, the accuracy or inaccuracy of any such configuration does not actually affect the accounts generated.

Getting Started

A good way to learn what can be done in the sponsors database is to simply read portions of it. SponsorsDataEditingTutorial purports to be a tutorial.

Tools

Various Unix command-line tools, run on cs-xh-admin.cs.private.uwaterloo.ca, allow privileged users to view and manipulate the sponsors data.

When adjusting resources for one user, the usual cycle is "userinfo" to see their current state, followed by manipulation of the sponsors database with a standard text editor, followed by "sponsor_resources", and then appropriate use of "accounts-client" to actually send the changes to the desired machine(s). For example, you might manipulate the sponsors database to give an existing user extra disk space (disk quota), or to cause an entirely new account (login name) to appear on a particular computer.

Documentation

See Also

-- AdrianPepper - 21 Jul 2011

Topic revision: r26 - 2019-02-04 - AdrianPepper
 
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