Обсуждение: Wall replay
I am realatively new to PostgreSQL. I have two servers in a Master/Slave relationship using WAL as the replication method. I have what I hope to be an easy question. If the Master goes down and before the slave is promoted, there may be a case where a log file may not have been shipped to the slave yet. If the new Master starts to process new transactions, is there a way to have it process the unshipped WAL files if they are copied to it? I do not see that case in the documentation.
Thanks you in advance.
Keith
Keith Ouellette <Keith.Ouellette@Airgas.com> writes:
> I am realatively new to PostgreSQL. I have two servers in a Master/Slave relationship using WAL as the replication
method.I have what I hope to be an easy question. If the Master goes down and before the slave is promoted, there may
bea case where a log file may not have been shipped to the slave yet. If the new Master starts to process new
transactions,is there a way to have it process the unshipped WAL files if they are copied to it? I do not see that case
inthe documentation.
You'd have to ship the remaining WAL over *before* the slave has come
up live, else it's too late.
If you're concerned about gaps of that sort, though, you should not be
using log file shipping at all. Set up streaming replication instead.
(If the PG version you're using hasn't got that, high time to move
to something newer.)
regards, tom lane