You can use different tools which detects if primary fails and automatically promotes standby.
To assure all data on standby you should use synchronous replication.
On Wed, 13 Jan 2021, 6:54 pm Pepe TD Vo, <pepevo@xxxxxxxxx> wrote:
>>If you shut down the primary server cleanly, all changes will be replicated,so you should be good.
>>During a failover, that is, if the primary suddenly fails, there is always
the possibility that you lose some transactions, unless you use synchronousyou said above which I don't need to run promote to make it failover as long as I set synchronous on? The last couple of weeks I have a failure on the primary server and can't run on a slave. It picks up as reading mode only.Bach-Nga
No one in this world is pure and perfect. If you avoid people for their mistakes you will be alone. So judge less, love, and forgive more.To call him a dog hardly seems to do him justice though in as much as he had four legs, a tail, and barked, I admit he was, to all outward appearances. But to those who knew him well, he was a perfect gentleman (Hermione Gingold)
**Live simply **Love generously **Care deeply **Speak kindly.*** Genuinely rich *** Faithful talent *** Sharing successOn Wednesday, January 13, 2021, 06:25:53 AM EST, Laurenz Albe <laurenz.albe@xxxxxxxxxxx> wrote:On Wed, 2021-01-13 at 09:27 +0100, Jan Peters wrote:
> we are running postgresqlserver on s390 zLinux machines. The distribution
> is RedHat 7 and RedHat 8, so we do not have the many x86 tools available.
>
> We always run 2 instances with a replication (streaming) async mode, the replica
> is in hot_standby and we use it for read-only accesses. About the setup we have the following question:
>
> How is an orderly failover accomplished? Our current procedure is.
>
> 1. primary stop
> 2. promote replica to primary
> 3. create standby.signal on old primary
> 4. change primary_conninfo on old primary
> 5. start old primary as new replica
>
> Is this processing correct? Are there any other steps that simplify a failover?
> How can we be sure that all changes have been transferred from the old master to the replica?
What you describe is not a failover, but a switchover.
If you shut down the primary server cleanly, all changes will be replicated,
so you should be good.
During a failover, that is, if the primary suddenly fails, there is always
the possibility that you lose some transactions, unless you use synchronous
replication.
Yours,
Laurenz Albe
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