Any idea why synchronization failed to asynchronous node.
Nothing more than what the errorlog shows.
During redoing of a logged operation in database 'MYDatabase',
an error occurred at log record ID (4234:121234:6). Typically, the specific failure is previously logged as an error in the operating system error log. Restore the database from a full backup,or repair the database.
Time-out occurred while waiting for buffer latch type 3 for page (1:9), database ID xx.
There was some logged operation which either explicitly or by way of another mechanism wanted to update the boot page (1:9). This wanted a latch of type 3 which is an
Update latch and it ended up timing out, which means it waited 300 seconds (5 minutes) which is the timeout value (not configurable).
There are various reasons this could occur, which comes down to two types of buckets.
The first are the ones that you can just resume and everything is fine, which means that this was due to some contention on the latches due to various internal and external reasons.
The second are the ones where resuming continually fails at the same LSN. These are hard failures and the database will need to be restored.
Regardless which bucket, there's essentially no chance to figure out why it happened after the issue occurred if there was no data collection setup and completed before the issue occurred. Thus, it's going to be impossible to say why just from this data.