Обсуждение:

Hi Pierre,

in my opinion it depends a bit from your setup, the workload and your goal.

Since streaming replication offers near-realtime data view, you might go
for that and offload your master too.

Also consider that there are more options, like pg_logical, which is
quite cool.

regards,

fabio pardi


On 11/2/18 4:56 PM, Pierre Ochsenbein wrote:
> Hey guy's,
> 
> What is your best recommendation for a PostgreSQL HA with two nodes if I
> use pgpool-II.
> Warm standby or read only with streaming replication?
> 
> Thanks
> 

>
> Also consider that there are more options, like pg_logical, which is
> quite cool.
>

I wouldn’t use pg_logical for HA; it should be an exact replica which pg_logical is not.

For an HA setup I would highly recommend using streaming replication with synchronous commits.  There is no reason to
risklosing a single committed transaction in a HA setup.  As far as managing the system which I believe your question
ismore about; that is going to depend on your environment and there are numerous cluster solutions out there;
personallyI use a CARP based solution. 

For DR it’s more customary to use asynchronous replication due to the high latency in most DR setups thus there is a
riskof losing committed transactions. 

> On Nov 5, 2018, at 11:25 AM, Pierre Ochsenbein <pierreochsenbein@gmail.com> wrote:
>
> but on your stdby you have configure a script to become the primary automatically?

Yes, as soon at the CARP address (i.e. the VIP) is migrated to the standby the database is promoted automatically.  All
theexisting TCP connections are reset/dropped and the clients reconnect to the new server within seconds.  

You have to researched the best solution for your given OS platform.  There are solutions that are platform agnostic
too. I don’t have a canned one to recommend though.