[Contrib: Evaluation System] Proposal to merge email changes into evaluation trunk

[Jim Eng]

We would like to merge our work on improved performance in processing email notifications into trunk of evaluation as soon as possible.  We describe the proposed changes below and ask for lazy consensus to merge these changes to trunk one week from now on May 2, 2011.  We will go ahead an merge those changes unless we have heard objections before noon EDT on that date (Monday, May 2, 2011 at 16:00:00 UTC).  

The proposed changes are described in a JIRA ticket:  

	https://jira.sakaiproject.org/browse/EVALSYS-1055

The changes have been checked into a branch of evaluation in subversion:

	https://source.sakaiproject.org/contrib/evaluation/branches/EVALSYS-1055-3/

A patch file is appended to the JIRA ticket:

	https://jira.sakaiproject.org/secure/attachment/25962/evalsys-1055.patch

Two screenshots attached to the JIRA ticket show the way the admin page for controlling email notifications looks if the features are enabled.  

	https://jira.sakaiproject.org/secure/attachment/25960/001-individual-selected.png
	https://jira.sakaiproject.org/secure/attachment/25961/001-summary-selected.png

The major change involves implementation of an efficient database query to select data for "consolidated" email notifications, which provide summary announcement and reminder emails. 

We believe this to be a very positive improvement over the current email-processing code in trunk of the evaluation module, which uses multiple database queries to obtain information needed to send email notifications. We have been told that sending individual reminder emails for 8,000 to 10,000 evaluations can take six hours or more using the code currently in trunk.  Notification emails can be sent to 20,000 users or more in less than an hour using the code that will be merged to trunk under this proposal.  The performance difference is primarily due to reducing the database activity to a few queries selecting based on well-indexed columns. This code also improves performance by sending fewer emails with use of a single "consolidated" email template that summarizes information about several evals, rather than sending separate emails about each eval in which a student is an evaluator.  

The ability to send separate emails for each eval is retained for anyone wanting that behavior.  

Please send questions and comments to this list.

Thanks.

Jim