[Building Sakai] Confusing LTI error message

[George Pipkin]

Hi -

   Please forgive me for posting this question a second time, but I have 
recieved no answers from my first posting over a month ago.

We've been noticing some log entries associated with LTI that tell us:

2014-05-23 09:54:31,028 ERROR localhost-startStop-1 
org.sakaiproject.lti.impl.DBLTIService - SQL Needed:

This despite the fact that we had already run the database conversion 
scripts successfully, doing so first by auto.ddl, and then on seeing the 
continuing error messages, doing so manually.A little examination of the 
code revealed that LTI was checking actual column sizes in the database 
against a table of desired sizes, and where there is a discrepancy, 
including "ALTER TABLE..." queries in a list of queries that is 
scheduled for execution upon an auto_ddl restart.The problem is, even if 
the actual columns are correct, the correcting query still goes into the 
list, and if you don't have auto_ddl activated, the error message cited 
above goes into the logs.The decision to include or not include the 
correcting query is made in the Foorm class, down in 
formAdjustTable(line 1395).What we think happens is the Mysql driver is 
not returning max sizes for the columns -- instead returning 3/4 max as 
an estimate of how many 1-to-4-byte Unicode characters the column can 
hold. This causes LTI to falsely assume they are incorrect and add them 
to the list of ones needing correction.This may not have turned up with 
Oracle, but it is a problem for schools using Mysql, as we do.Even 
though the message can be ignored, in situations where auto-ddl is 
activated at attempt to correct the field is actually made, and this 
involves a DB lock which can endanger a melt-down in some situations.Is 
there some way to address this issue ?





- GeorgePipkin
                                 U.Va.
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