Re: Transaction-controlled robustness for replication

On Tue, 2008-08-12 at 11:51 -0400, Bruce Momjian wrote:
> I think you need to make it an enumerated type like log_min_messages; 
> something like:
> 
>     wal_transfer_wait

Yeh, that way sounds best and I like name.

> with values of:
> 
>     nothing:    have network traffic send WAL as needed
>     netflush:    wait for flush of WAL network packets to slave
>     process:    wait for slave to process WAL traffic and
>             optionally fsync

Suggest  async syncnet syncdisk

> The 'process' option either waits for fsync on the slave or not
> depending on how the slave is configured, meaning you could use
> synchronous_commit off to not wait for the fsync to disk.

Hmmm, not sure that flicking a switch on the standby should cause a loss
of performance on the master. That will be an accident waiting to
happen. Best to make all things that effect the performance/robustness
of the master be configuration options on the master side.

> I think we can add a table in the documention to show how to set things
> up in postgresql.conf for async master and async slave, and other
> combinations.

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Training, Services and Support