Volume 2. No 3 Information Technology News of the University of California, Davis Spring 1994

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Electronic Mail Crisis Has Passed

by Dan Dorough, Distributed Computing Analysis & Support
and
Dana Drennan, Information Resources

Around second week of January 1994, electronic mail on IT-managed machines UCDavis and Bullwinkle bogged down. Load on network monitoring and other software contributed to the slowdown, but the problem was essentially that email traffic, both incoming and outgoing, had reached a phenomenal rate of almost 40,000 messages per day.

IT staff dealt with the problem in several stages over the next weeks. On February 21, the most significant change occurred when we installed new email routing software and completely changed the routing structure. After a few problems with the software were worked out, email began transmitting normally again. On February 27, we put new processor boards on Bullwinkle, which further increased the capacity of that system. No problems with email delivery have been reported since then.

Now IT is looking to get ahead of the wave - by adding a Sun SparcServer 1000 to handle email routing. This machine will add four times the capacity of the current Bullwinkle (retaining the name Bullwinkle, however). IT expects that the new machine will handle email traffic without problems for another year. At the end of one year, IT will increase system capacity again as needed.

User Expectations for Email High

The system was originally designed for a 2-day turnaround. That is, after two days, undeliverable mail is returned to the sender. However, for many years, email users have received and expected much faster delivery. It was rare for a local message to reach an on-campus destination in more than an hour. During the recent crisis, people were upset that it was taking 4-6 hours for email transmission. In some instances, it took a day.

Some situations come up that are completely out of local control.

For example, a number of departmental systems on campus have frequent periods when they do not accept electronic mail delivery. When mail is sent to a user on such a system, delays in email delivery may occur. IT does not control those systems.

Another example: Outgoing messages addressed to the same system may take different paths over the Internet. Sometimes, an earlier message can arrive after a later message sent to the same person. IT has no control over electronic mail once it has left campus.

IT remains committed to meeting expectations and strives to provide a service that delivers 99% of messages in one hour. With the recent and pending changes to the system, client satisfaction should be on the rise again.