Limit of WAL LSN value of type pg_lsn

[Shubham Shingne]

Hi all,

I am trying to determine optimal standby for automatic failover based on
pg_last_wal_recieve_lsn() value of all slaves.

But what if max_wal_size is reached, is LSN value reset to zero.

Please share some documentation that mentions clarification.

Also suggest if there is any better approach to get node with best RPO out
of all slaves.

Thanks & regards,
Shubham