NOTICE DATE: September 21, 2015

NOTICE TYPE: M-A092015-03 Unplanned Outage

SHORT DESCRIPTION: Unplanned Outage of some ERCOT systems – Unplanned Fail-over

INTENDED AUDIENCE: ERCOT Market Participants

DAY AFFECTED: September, 21, 2015 17:00 to 20:00

LONG DESCRIPTION: ERCOT will be performing a controlled fail-over at 17:00 this evening. During this fail-over, the following market-facing systems will be intermittently impacted:

· 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

· MOTE

· NMMS

· Find ESI ID and Find Transaction

ADDITIONAL INFORMATION: The potential for additional system issues was identified during testing and validation. As a precaution, ERCOT will perform a controlled fail-over and operate key systems in the alternate data center. This will allow preventative maintenance to be completed on affected systems.

Missed report posting information will be sent in a follow-up Notice.

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].

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.