Analytics high-availability in multi-site set-up

We have two sites that participate the set up that secures the uninterrupted operations for API traffic (high availability: active-passive). The analytics data needs to be collected uninterruptedly from the active site. See Use Case for more details of the customer set-up and description of requirements.

We are looking to have the same service level and be able to use Analytics (data collection & reporting) in v10 the same way as in v5 but have bumped into some constraints and limitations in v10:
- Rate Limit ensured only between DP servers in one cluster
- Single DataPower Service can have only single Analytics Service associated
- Multiple Analytics Services per catalog disable analytics for Developer Portal
- DataPowers pushes analytics data via loadbalancer endpoint
- API Manager pulls analytics data via loadbalancer endpoint
- Not possible to have ACTIVE-PASSIVE setup for Analytics clusters (possible for APIM and DEVPort). - Not possible to synchronize data between Analytics clusters
- Nodes inside one (analytics) cluster should have latency under 6ms

We have looked into possible alternatives together with IBM specialist:
1) one Analytics service serving several sites: not possible
2) one site solution for Analytics where data is buffered on DP in another site for the duration of issue and then fed back to the site where Analytics reside: queuing/buffering not possible between Analytics and DP
3) regular back-ups and manual data restore: considerable maintenance overhead, error-prone manual process at the time of failure, data losses. Requires identical hostnames for both sites which is not possible at customer end.
4) external storage filesystem: solution not tested at IBM end. Requires buidling a customised solution at customer's end and does not fulfill the business requirements of using API Connect product for all API management aspects, including operations monitoring, analytics and reporting.