Hi @ingenthr,
Re: guarantee replication across XDCR.
I work in a large financial institution and RPO zero (zero data lost when a site is wiped out) gets toss around quite often because we can afford to build low latency network between sites with synchronous disk write across sites and it is easy for infrastructure team to recommend database solutions system that provides RPO zero for all types of transactions because no caveats need to be given. It’s a big hammer approach.
In reality, most data doesn’t need to have RPO zero. It would be very handy if couchbase sdk offer a mode that guarantee replication across configured XDCR. For certain type of transaction, if we are prepared to/required to wait then that would make the solution more adaptable as we can then choose appropriate level of consistency with tradeoff in the time that the transaction might take.
If there are failure in site replication then we’d expect couchbase to rollback the data that was persisted locally.