Can someone point me to the MS article or blog post that explains in details how AlwaysOn Availability Group secondary replica catches up with primary after secondary server long downtime?
I did below tests with AAG (async, manual failover, read-only configuration). A) Killed secondary instance during continuos insert into primary and started secondary instance few minutes after. AAG dashboard turned into a green almost immediately after secondary restart and started to catch up with primary until number of rows became the same in both instances. No transaction log backup was done. B) Same as A) but few transaction logs were done from primary during the test.
1) What is the size of log cache/messaging framework etc that are used to keep tran log blocks (which are sent to secondary replica)
2) Can above structure (log cache/send queue etc - whatever is used as transport for AAG replication) sizes be configured/increased (similar to encrease of tran log backup retention period in log shipping, for example)?
3) As I backed up (truncated) tran log in test B) and secondary replica was syncronised with primary automatically what was used to find row difference between primary and secondary (apparently not tran log as it was truncated) and then bring then in sync?
4) How does this automatic catch up process work and what are its limitations?