Sudden Onset Freezes and Lockups - Ideas

["Karl Beiser" <beiser at maine dot edu>]

Beginning a week ago our Minerva consortial system has had a very frustrating 
problem with momentary freezes and hard Millennium client lockups that come 
with such frequency that the various Millennium clients are virtually 
unuseable. Any experience or insight you might have with this sort of thing 
would be much appreciated.

Problem Description

Millennium Circulation, Cataloging, Serials "hesitate" 10 seconds to a minute 
or more between mouse clicks and keystrokes. This can happen at any point. 
There is no pattern to when this happens or what the user is doing at the 
time.  These hesitations can happens as frequently as every minute or two, 
though once every 5-10 minutes is more common.

Often, the "hesitations" appear to never end.  They turn into full lockups.  
Staff must use the Windows Task Manager to close down the client, then start 
up a new one.  Other client software runs normally during the lockup.  

This problem occurs only in libraries that connect to the server through our 
statewide Maine School and Library Network (MSLN).  Those using a DSL or 
cable modem circuit do not have the problem.  However, only 1/4 of the MSLN 
libraries have the problem -- about 10 libraries.  Those 10 libraries have no 
geographical or network topology commonalities that separate them from the 
other libraries as far as we can see.

The problem has been very nearly constant for about a week among the 10 
affected libraries.  Pretty much all the Millennium client machines behave 
about the same, irrespective of operating system.  The machines are all over 
the map in respect to workstation memory, from 128 MB to 1 GB of RAM, from 
Win 98, NT, 2000 to XP.

Oh, and bandwidth tests indicate that there is plenty of available network 
bandwidth coincident with these problems. There could be downward spikes, but 
in general terms the bandwidth is not being strangled by some other factor.

Any suggestions, insights, clarifying questions, etc. would be much 
appreciated as we work with the folks who host our server and manage MSLN to 
try to uncover what is an elusive and probably compound cause of this 
problem...

Regards,

Karl
-- 
Karl Beiser, Library Systems Coordinator
Maine State Library
POB 2145
Bangor, ME 04402
beiser at maine dot edu
tel:207-581-1656; fax: 207-581-1653; pager: 207-750-0330
http://www.maine.gov/msl/