Re: High Availability and Replication

Hi,

When Master server goes down, either you need to promote one of slave node
or configure HA mechanism so that in case of master server goes down it
will automatically promote the slave server as new master.

Patroni HA tool would be good option for your requirement.

https://patroni.readthedocs.io/en/latest/README.html

Hope this helps.

Thanks & Regards,
Abdul Sayeed
PostgreSQL DBA

On Sat, 2 Mar 2024 at 2:15 AM, Israel Brewster <ijbrewster(at)alaska(dot)edu>
wrote:

> On Mar 1, 2024, at 11:36 AM, normandavis1990 <normandavis1990(at)proton(dot)me>
> wrote:
>
> > On Thursday, February 29th, 2024 at 11:38 PM, Israel Brewster <
> ijbrewster(at)alaska(dot)edu> wrote:
>
> On Feb 29, 2024, at 10:15 AM, David G. Johnston <
> david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
>
>
>
> On Thursday, February 29, 2024, normandavis1990 <normandavis1990(at)proton(dot)me>
> wrote:
>
>>
>> What is the difference between High Availability and Replication?
>>
>
> The former is a goal, the later is a technique.
>
>
> Perhaps more specifically: Replication is simply Replicating - or copying
> - the “master” database to one or more “slave” databases, generally in
> real-time such that the slave database clusters are replicas of the master.
> This is good when the master goes down, because you’ll still have one or
> more copies of it available, but by itself it doesn’t keep there from being
> an outage if/when the master goes down.
>
> High Availability layers on top of replication to provide some means of
> ensuring that the database is HIGHLY available, such as an automatic
> failover system or load balancer. Many different options that work in many
> different ways are available to help meet this goal.
> ---
> Israel Brewster
> Software Engineer
> Alaska Volcano Observatory
> Geophysical Institute - UAF
> 2156 Koyukuk Drive
> <https://www.google.com/maps/search/2156+Koyukuk+Drive+Fairbanks+AK+99775-7320?entry=gmail&source=g>
>
> Fairbanks AK 99775-7320
> <https://www.google.com/maps/search/2156+Koyukuk+Drive+Fairbanks+AK+99775-7320?entry=gmail&source=g>
> Work: 907-474-5172
> cell: 907-328-9145
>
>
> David J.
>
>
>
>
> Hi,
> You said "This is good when the master goes down, because you’ll still
> have one or more copies of it available, but by itself it doesn’t keep
> there from being an outage if/when the master goes down.". What does "goes
> down" mean?
>
>
> Exactly what I said - it goes down. Not functioning. Offline.
> Inaccessible. It is not up and running, therefore, it is down.
>
> In Replication mode, if the primary server is shut down, then the data
> will also be lost?
>
>
> No. As I said - and you quoted - “When the master goes down…you’ll still
> have one or more copies of it available”. So no, the data will NOT be lost.
>
> ---
> Israel Brewster
> Software Engineer
> Alaska Volcano Observatory
> Geophysical Institute - UAF
> 2156 Koyukuk Drive
> <https://www.google.com/maps/search/2156+Koyukuk+Drive+Fairbanks+AK+99775-7320?entry=gmail&source=g>
>
> Fairbanks AK 99775-7320
> <https://www.google.com/maps/search/2156+Koyukuk+Drive+Fairbanks+AK+99775-7320?entry=gmail&source=g>
> Work: 907-474-5172
> cell: 907-328-9145
>
>