[pgpool-general: 7260] Re: Pgpool-HA without watchdog, kubernetes scenario.

Bo Peng pengbo at sraoss.co.jp
Wed Sep 2 15:30:06 JST 2020


On Tue, 1 Sep 2020 17:24:15 +0200
Rafael Rios Saavedra <rafael.rios.saavedra at gmail.com> wrote:

> Hi,
>   First of all I am not very sure if this is the right list to post this
> question, if it is not, please point me to the appropriate place.

Yes. Here is the right place to ask questions related to pgpool.

>   I would like to deploy pgpool in HA in kubernetes, but as kubernetes
> handle all the liveness test of the nodes, load balancing and "virtual" IPs
> handling, I would like to know what I should configure in pgpool.
>   Let's say I would like to run 2 instances of pgpool, 

As you said K8s will handle all the liveness test of the nodes,
why do you need 2 instances of pgpool?

> if I have a Load
> balancer that send requests to the nodes, Would it be safe to do just that,
> or does a pgpool instance need to know the others to sync some information
> ?.

Do you mean you will send queries via another load balancer, not via pgpool?
It is possible to send queries without going through pgpool.

Below is an example of configuring pgpool on k8s.


>   I have seen this
> <https://www.pgpool.net/docs/latest/en/html/example-aws.html> and this
> <https://www.pgpool.net/docs/latest/en/html/example-aws.html> pages, but it
> is not clear to me if the `other_xxxx` parameters are used just for
> watchdogging or there is more involved that I am missing.

Yes. "other_xxxx" is used only for watchdog.

> Example configuration from the AWS link.
> use_watchdog = on
> delegate_IP = ''
> wd_hostname = 'instance-1-private-ip'
> other_pgpool_hostname0 = 'instance-2-private-ip'
> other_pgpool_port0 = 9999
> other_wd_port0 = 9000
> wd_escalation_command = '$path_to_script/aws-escalation.sh'
> wd_de_escalation_command = '$path_to_script/aws-de-escalation.sh
> Thanks forehand.

Bo Peng <pengbo at sraoss.co.jp>
SRA OSS, Inc. Japan

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