Shanghai II (SHA2), Beijing (BJS1), Beijing III (BJS3) Datacenter Issue

Zscaler is currently investigating reports of an issue with its Shanghai II (SHA2), Beijing (BJS1), Beijing III (BJS3) datacenters. We are investigating periods of slowness, connection timeouts and/or increased latency. If you’re currently experiencing any traffic impacting issues please failover to your secondary DC or any other alternate DC. For more information, please refer to the following support article. We will continue to provide updates here as the investigation progresses. For detailed updates, please check the Service Status section in your Zscaler customer support portal (CSP). Status changes and updates will be posted there as they become available.Latest Update - Tue, 23 Dec 2025 11:34:21 UTCWe continue to monitor the situation and validate the mitigation applied, while gathering customer feedback. We plan to extend this change during the next off-peak maintenance window and will provide the next update as we proceed.Update - Mon, 22 Dec 2025 08:24:46 UTCZscaler has implemented mitigation for the issue. Our systems remain fully operational, and we will continue to monitor closely to ensure ongoing stability.Update - Mon, 22 Dec 2025 10:58:22 UTCThe issue has resurfaced, impacting Shanghai II (SHA2), Beijing (BJS1), Beijing III (BJS3) datacenters with intermittent slowness, timeouts, and increased latency. We are investigating further and will share updates when available.Update - Mon, 22 Dec 2025 15:50:23 UTCZscaler is prioritizing the issue and is actively working to isolate the problem and identify the root cause. We appreciate your patience and understanding during this investigation. Additional updates will be provided as more information becomes available.Update - Mon, 22 Dec 2025 18:12:17 UTCWe have not yet received an update from the initial service provider we engaged. In parallel, we are working with another provider familiar with the issue to continue the investigation and determine recommended actions. We will share further updates as soon as more information becomes available.Update - Tue, 23 Dec 2025 03:30:02 UTCWe have not yet received an update from the providers we engaged. We are contacting them to confirm the recommended next steps and will share further updates as soon as additional information becomes available.Update - Tue, 23 Dec 2025 07:20:32 UTCWe applied a partial mitigation on the BJS3 ZSN cloud by shifting to alternative public DNS resolvers and are observing the issue and related metrics. We are monitoring error rates and resolution latency, coordinating with external partners, and will review the metrics to discuss the effectiveness of the change and decide next steps at the upcoming checkpoint.Update - Tue, 23 Dec 2025 08:37:37 UTCWe applied a partial mitigation in our Beijing (BJS3) environment by switching to alternative public DNS resolvers, which has significantly reduced DNS errors. Validation confirms these resolvers successfully resolve the affected domains, whereas the previous resolvers were intermittently not able to get response from authoritative DNS servers. Some users may still experience intermittent issues. We plan to extend the change during the next off-peak maintenance window and will provide the next update as we proceed.Update - Tue, 23 Dec 2025 11:34:21 UTCWe continue to monitor the situation and validate the mitigation applied, while gathering customer feedback. We plan to extend this change during the next off-peak maintenance window and will provide the next update as we proceed.