Recently, extreme high temperature weather in California caused a large area of ​​Twitter data center to be paralyzed. Another company executive said in an internal memo obtained by CNN that another outage at other data centers could result in some users being unable to use Twitter.

Like most social media platforms, Twitter relies on data centers, which are essentially huge warehouses full of computers, including servers and storage systems. It is important to control the temperature in these data centers to ensure that the computers do not fail due to overheating. To save on cooling costs, some tech companies want to build their data centers in colder climates. For example, Google opened a data center in Finland in 2011, and Meta has had a data center in northern Sweden since 2013.

“On September 5th, Twitter suffered huge losses due to the failure of its Sacramento data center due to extreme heat that shut down all of SMF’s physical equipment,” Carrie Fernandez, vice president of engineering at Google, said in a message to Twitter engineers.

Large tech companies often have multiple data centers just to ensure their services remain online if one of the centers fails, a state known as redundancy.

According to Fernandez’s memo, Twitter was in a “non-redundant state” due to the power outage in Sacramento. “Twitter’s Atlanta and Portland data centers are still operating, but if we lose either of those data centers, we may not be able to serve Twitter users,” she explained.

Twitter now prohibits non-critical product updates until the Sacramento data center is restored. “All product changes, including deployments and releases to mobile platforms, will be blocked, except for urgent needs,” Fernandez wrote.

The restrictions underscore the apparent fragility of Twitter’s underlying systems, an issue that Peiter Zatko, Twitter’s former security chief and turned whistleblower, reported in a whistleblower document sent to lawmakers and government agencies in July. In first reports by CNN and The Washington Post, Zatko said Twitter’s “insufficient data center backup” would increase the risk of brief service outages that could even cause Twitter to go offline forever.

“Even brief, multiple outages in a small number of data centers can take Twitter offline for weeks, months, or forever,” according to whistleblower Zatko.

The news of the data center outage came the day before Zatko went to testify in the Senate.

Twitter did not disclose the number or locations of its data centers, but whistleblowers said a public news report indicated that Twitter has data centers in Sacramento and Atlanta. In 2020, Amazon announced that Twitter had chosen its cloud computing platform to serve some tweets from Amazon’s data centers.

In a statement about the Sacramento power outage, a Twitter spokesperson told CNN, “There is no impact on Twitter access and usage at this time. Our team is operating normally and will continue to provide users with a smooth experience.”

Former U.S. government chief information security officer Greg Touhill said: “Data centers need adequate water, electricity, proper humidity and strong cooling to survive.”

“You need to have backup data centers to enhance your network resiliency so you can mitigate the negative impact of a data center failure,” Touhill, head of the CERT division at Carnegie Mellon University’s Software Engineering Institute, told CNN.