I have a alwayson cluster with 4 instances in ASYNC mode.. 2 Instances on SITE A and 2 on B. When there is large operation happens in primary, secondaries goes behind. Most of the time when its goes behind i see log send queue is 60 in replicas.But when i switch to SYNC mode,log send queue immediately populates to much larger value.
what is really happening when i change the mode from ASYNC to SYNC when secondary is behind? or vice versa.any doc tell about this?
Best Regards, Arun http://whynotsql.blogspot.com/