St Andrews SITS Apps interaction

Report
SITS Interactive Apps at St
Andrews
• Two key applications that interact with
SITS:
– MMS: institutional data flow management tool
suite
– Admissions: does what it says on the tin
• As of Jan 2013 MMS is read/write via DB
• Admissions is read via DB, write-back
using StuTalk
MMS
• MMS is primarily designed to minimise
manual handling of data
• Extracts data from SITS over database
links, including:
– Courses, course enrolment
– Degree intention, supervisors (PGR)
– Course results for degree classification
– Exceptional circumstances
– Disability information
MMS (2)
• Data written back semi-automatically
• CSV files generated for end-of-course
results
• Imported in batch operations through SITS
client
• As of Jan 2013, work partially completed
for writing back automatically as XML
feeds
MMS (Students on Module)
Admissions
• Reads SITS data directly from database
– Performance issues performing mass-reads
over StuTalk
• Reads SITS data for update over StuTalk
• Writes decisions back via StuTalk web
services
• Student details, applications, etc. written
back via StuTalk XML
Admissions (Applicant Import)
Feedback
• Very positive response to user interfaces
– Substantially simpler to adopt institutional look
and feel
– SITS-specific detail generally hidden from
user
• Issues with performance
• Issues with reliability
• Hiding implementation detail can cause
confusion
StuTalk Web Services v8.5.1
• SOAP based
• Ability to run processes
– Assign new student ID
– Generate reports
– Etc.
• Immediate feedback on success/failure
– Useful for development
– Well suited to small interactive tasks
– Can report outcome directly to user
StuTalk Web Services (2)
• Poorly designed
– JSON in SOAP
• XML in JSON in SOAP!
– Base64 in App
XMLEngine
in JSON
in SOAP!?
Datastore
– No use of standard authentication tools
– No transaction safety
• Slow (200-500ms/request)
• Limited support for writing multiple records
– Embedded XML feeds
StuTalk Web Services Request
<soapenv:Body>
<urn:ACTION>
<urn:USER>stutalk</urn:USER>
<urn:PASSWORD>topsecret</urn:PASSWORD>
<urn:DELIMITER>JSON</urn:DELIMITER>
<urn:FUNCTION>DMU</urn:FUNCTION>
<urn:PARAMETERS>{"ACTION":"UPDATE","DCT":"SRS","ENT":"CAP"}</urn:PARAMETERS>
App Engine Datastore
<urn:INDATA>
{
"cap_stuc":"120004054",
"cap_apfs":"01",
"cap_seqn":"01",
"cap_blok":"24",
"cap_qstc":"NQ", }
</urn:INDATA>
<urn:MD5>b447291e73dc268a717e276c2e96da0b</urn:MD5>
</urn:ACTION>
</soapenv:Body>
StuTalk XML
•
•
•
•
Intended for bulk data import/export
Appear more robust for simple data sets
Some issues with mixed data sets
Writing back inter-related data sets has
issues with primary key generation
– For example CAP, APF and STU for a new
student application
• Require shared space for storing XML files
StuTalk XML Example
<EXCHANGE>
<stu>
<stu.ins>
<stu_code>01234567890</stu_code>
<stu_had1>1 Made Up Street</stu_had1>
App Engine Datastore
<stu_had2>Edinburgh</stu_had2>
<stu_hapc>EH1 2AA</stu_hapc>
<stu_haem>[email protected]</stu_haem>
</stu.ins>
</stu>
</EXCHANGE>
Reading by Database
• Fast
– Especially joining tables
• Risk of issues due to schema changes
• Non-database fields cannot be accessed
– Unaware of any times this was an actual
problem
Writing by Database
• Fast, however:
– No SITS triggers
– No integrity constraints
– No feedback
• Cannot run processes
– For example student ID assignment
• Usable only in very simple use-cases
StuTalk Interaction Layer
• Developed in-house at St Andrews
• Web service & XML wrapping layer
• Hides implementation details
– Allows easy re-targeting of SOAP & XML
interfaces
• Simple object-mapping layer
– Data object definitions automatically
generated from SITS ENT & FLD records
Summary
•
•
•
•
In theory, good
In practice, some significant challenges
Likely to be worth persevering with
Upcoming changes/improvements to
StuTalk?
– “Beta” API in 8.5.1
Suggestions
• StuTalk XML feed into EUGEX
• Staging database for changes to go to
SITS
• Work with Tribal on API to improve key
issues:
– Lack of transaction support
– Performance (session instantiation?)
– Read/write related records as a batch
Questions?

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