Read this section before you purchase and use Alibaba Cloud Edge Node Service (ENS).
Node Resources
Edge nodes support local disks and ultra disks. Available disk options vary by node.
A local disk resides on a single host. Its data reliability depends on the host’s reliability. Local disks are subject to single point of failure and data loss. If your application requires high data reliability, implement data redundancy at the application layer.
You have full usage rights to the node resources provided by ENS for the duration of your subscription. You do not have usage rights to any node resources not provided by ENS. If you use node resources without authorization, ENS may take action against those unauthorized resources and their associated instances.
Some ENS nodes may be retired due to supplier changes or other factors. We notify you of retirements and list replacement nodes—within the same province and under the same carrier—on the Cloud Monitor platform at least 15 days in advance. Configure email or phone alerts in Cloud Monitor to receive these notifications. On the retirement date, the node stops service and releases resources. Back up your data, release resources, and migrate your workloads before then.
All tenants on a single edge node share the same public bandwidth egress. Billing is based on usage. Per-tenant, per-node bandwidth is capped at 5 Gbps. To request additional bandwidth, contact your sales representative or submit a ticket.
Node O&M
ENS guarantees a service availability of at least 99.9%, as defined in the Service-Level Agreement (SLA). For details, see Service Level Agreement. This SLA does not cover downtime caused by carrier core network failures, scheduled system maintenance announced in advance by Alibaba Cloud, network or device failures outside Alibaba Cloud’s control, or issues caused by customers.
Network cutover occurs on edge nodes no more than once per month per node. Each cutover lasts no longer than six hours.
Carrier networks may experience unexpected outages or jitter. ENS monitors node networks 24/7 and reports events to Cloud Monitor. Configure Cloud Monitor to send alerts via email, phone, or API so you stay informed about node network status in real time.
The reliability of local disk instances depends on host reliability. If a single point of failure occurs, ENS migrates the instance to another host within the same node to restore connectivity as soon as possible. Data reliability is not guaranteed.
If a single edge node becomes unreachable, ENS migrates your instance to another node in the same region to restore regional connectivity as soon as possible. The instance ID remains unchanged, but the instance IP address changes. Data reliability is not guaranteed.