NOTICE DATE: October 1, 2015 NOTICE TYPE: M-A092015-06 Unplanned Outage SHORT DESCRIPTION: Unplanned Outage of some ERCOT systems – Unplanned Fail-over INTENDED AUDIENCE: ERCOT Market Participants DAY AFFECTED: October 2, 2015 10:00 – 16:00 CPT LONG DESCRIPTION: On October 2, 2015, ERCOT will perform a controlled fail-over between data centers to allow for further preventive maintenance to be completed on systems currently used to operate applications involved in the fail-over on September 21, 2015. During this fail-over, the following market-facing systems will be intermittently unavailable at the corresponding times: 10:00 – 12:00 CPT · Find ESIID 13:00 – 16:00 CPT · Find Transaction for historical searches (greater than 1 year) · Market Data Transparency (MDT) Web Services · Extract Subscriber · Net Dependable Capability and Reactive Capability (NDCRC) 15:00 – 16:00 CPT • Components of the ERCOT Market Information System (MIS) including: o Report publishing to the MIS o Downloading of extracts and reports from MIS and External Web Services (EWS) · MIS and ERCOT.com dashboards and displays CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at [log in to unmask]<mailto:[log in to unmask]>. If you are receiving email from an ERCOT distribution list that you no longer wish to receive, please follow this link in order to unsubscribe from this list: http://lists.ercot.com. sa