Assume there is a 7 member replica set, where each node is a voting member and no arbiter node is present. For a
write w1, Using
w:majority would ensure that a write is written to the journal and let's assume to the disk also after the default time interval.
If 3 nodes fail (all having the write
w1 mentioned above) at the same time including the primary, only one of the remaining 4 nodes has the write
w1. If this node does not get enough votes (say it's overloaded and will not be suitable for role of a primary), and some other node gets all enough votes to become primary, we have basically lost the write
I know this is a rare case, but it still can happen. So isn't it true that using
j= true and
w:majority also will not assure that the writes are durable?