DBS Bank customers, who already had experienced multiple service disruptions in recent months, were unable to access various services on Saturday, including mobile banking and peer-to-peer funds transfer service, PayLah. The bank's ATMs also were down.
Citi Singapore customers reported similar disruptions, with the bank confirming there were "issues" transacting with its ATMs, credit cards, and mobile app, among others.
In subsequent updates on its Facebook profile, DBS said the disruption was caused by an issue with its data center service provider, Equinix.
"We are doing our utmost to swing over to our backup data center and expect to progressively restore services," the bank said. By late night on Saturday, it posted an update to notify customers its ATMs had resumed operations, but some services such as its online services remained unavailable.
In an update Sunday morning, DBS said all its services were back up and running. The bank in 2017 partnered with Equinix to move its main data center to smaller "cloud-optimized" premises, enabling DBS' to run the facility at 75% cheaper.
ZDNET contacted Equinix with questions regarding the service disruption, including why its failover measures and secondary site were unable to prevent the incident, and how many organizations were impacted.
In an email response, an Equinix spokesperson said: "On Oct. 14, a technical issue with the chilled water system occurred during a planned system upgrade at one of our data centers in Singapore. This raised the temperatures in some of the halls in the data center and impacted some customer's operations. The technical issue has been resolved and we are in contact with impacted customers."
The spokesperson said the vendor currently is "thoroughly investigating" the incident and will offer more details when these are available.