ECS 3.5.0.1 Administration Guide

Two-site geo-federated deployment with ADO-enabled buckets

When an application is connected to a non-owner site, and it modifies an object within an ADO-enabled bucket during a network outage, ECS transfers ownership of the object to the site where the object was modified.

The following figure shows how a write to a non-owner site causes the non-owner site to take ownership of the object during a TSO in a two-site geo-federated deployment. This functionality allows applications connected to each site to continue to read and write objects from buckets in a shared namespace.

When the same object is modified in both Site A and Site B during a TSO, the copy on the non-owner site is the authoritative copy. When an object that is owned by Site B is modified in both Site A and Site B during a network outage, the copy on Site A is the authoritative copy that is kept, and the other copy is overwritten.

When network connectivity between two sites is restored, the heartbeat mechanism automatically detects connectivity, restores service, and reconciles objects from the two sites. This synchronization operation is done in the background and can be monitored on the Monitor > Recovery Status page in the ECS Portal.