1. Annie Griffith November 2007 Gemini OSU - UKLC Update

2. Drivers for Upgrade to Oracle 10g  Prior to 21 st Oct Gemini running on Oracle version 9i systems  xoserve notified by Oracle that version 9i would no longer be supported post April 07  System changes to move to Oracle version 10g planned, and tested prior to October go-live  Extensive testing programme  2 months integration and system testing  8 weeks UAT  4 weeks shipper trials (voluntary)  7 weeks dress rehearsal  Shippers advised of planned outages on 14 th and 21 st Oct

3. Overview of events  21 st Oct – upgraded system implemented –  API errors identified  22 nd Oct – issue with Shipper views of other shippers’ data  shipper access revoked  24 th Oct – Code fix for data view implemented  internal National Grid access only  26 th Oct – external on-line service restored  1 st Nov – hardware changes implemented to external service  2 nd Nov – API service restored  Further intermittent outage problem occurring  5 th Nov – Last outage on API service recorded at 13:00  work on full resolution still ongoing.

4. Sunday 21 st October  Planned outage expected 04:00 – 12:00  Outage time exceeded by 3 hours, system restored at 15:00 Sunday afternoon  Initial shipper error regarding intermittent API functionality and system access received 5pm  Gemini issues escalated to highest priority – shippers notified and advised that contingencies not being invoked at this time.

5. Monday 22 nd October  00.20 – system fix put in place and shippers advised  14.20pm – Shipper reports being able to see another User’s data in one of the Gemini re-nomination screens.  Action:  Verified report and then immediately initiated removal of shipper access to system (14.25).  Manual code contingency processes triggered – staff and facilities mobilised.  Shippers notified via ANS that Code Contingency arrangements had been triggered. External User access removed.  Investigations commenced to determine cause of problem

6. 23 rd -26 th October  Investigations identified application code construct error  Wed 24 th 04:15 Weds 24 th Oct  Apparent errors still present via external stack so further investigations activities continued  Fri 26 th 15:00 External on-line service restored, without API service  Fri 26 th 16.50 – Gemini access temporarily suspended to allow further checks/tests after shipper reports of data issues  Fri 26 th 21.30 - Data issues resolved and Gemini external on- line service returned

7. Further actions 1 st – 5 th Nov  Thu 1 st Nov – full Gemini external configuration restored  Fri 2 nd Nov - API service restored for Users  Intermittent service experienced by both API and on-line Users  Problems different to those experienced before and after Oracle upgrade  Sat 3 rd - API service upgrades applied  Intermittent service continues with some improvement  15 to 20 min disruption every 2 - 2 ½ hours  Sun 4 th – further API service upgrades applied  Intermittent API service continues with noticeable improvement (6-8 hours between occurrences)  Mon 5 th - API service upgrades and isolation of API intermittency from ‘direct access’ users  effects on on-line users eliminated  noticeable improvement for API Users – last disruption 13:00 Monday, resolution still ongoing