At the end of a peer recovery the primary wants to mark the replica as in-sync. For that the
persisted local checkpoint of the replica needs to have caught up with the global checkpoint on the
primary. If translog durability is set to ASYNC, this means that information about the persisted local
checkpoint can lag on the primary and might need to be explicitly fetched through a global
checkpoint sync action. Unfortunately, that action will only be triggered after 30 seconds, and, even
worse, will only run based on what the in-sync shard copies say (see
IndexShard.maybeSyncGlobalCheckpoint). As the replica has not been marked as in-sync yet, it is
not taken into consideration, and the primary might have its global checkpoint equal to the max seq
no, so it thinks nothing needs to be done.
Closes#43486
d45f12799c