Re: [Postgres-xc-general] Corosync Resource configuration for Postgres-XC

[ssoorruu <sso...@gm...>]

Hi Suzuki-san,

Thank you for responding to my email.
At first, your question was sound tough for me (because I'm new to
DRBD, Postgres and Corosync/Pacemaker/Heartbeat).
After I re-read the tutorial and the DRBD references, I'm sure that
the I have configured the DRBD to run Fully-synchronous (called
protocol C in DRBD term) in fixed rate (1Gbps).

I've read your presentation slide about: High Availability in
Postgres-XC, The symmetric PostgreSQL cluster
In that presentation you were using Pacemaker/Hearbeat with Postgres-XC.


Would you share to me the guide of how to configure the
Pacemaker/Heartbeat with Postgres-XC?
Or maybe you have publish it, can I have the link to your tutorial
about Postgres-XC-Pacemaker/Heartbeat?


Big thanks,
FattahRozzaq
--
On 26/08/2015, Koichi Suzuki <koi...@gm...> wrote:
> Hello;
>
> I just know general thing about DRBD, Corosync and Pacemaker so I'd like to
> post my comment with a question of DRBD basics.
>
> First of all, I have one important questions on DRBD basics:
>
> Does DRBD send all the update to slaves in synchronous manner, or is there
> any chance that DRBD slave fails to receive some of the updates at the
> master?
>
> If you cannot configure DRBD update backup synchronously, we may have some
> consistent issue among the data stored in different datanodes.
>
> The background is:
>
> Postgres-XC assumes consistency of data stored in all the coordinators and
> datanodes.    If some coordinator/datanode fails and is switched to the
> slave, the slave must not lose any commits done to the master.
>
> This is the same in the case of log-shipping replication and this is why I
> advise to use synchronized replication.
>
> If you can keep slave in sync with the master, then what you should do is
> to start Postgres-XC component at the slave.
>
> Thank you very much;
>
> ---
> Koichi Suzuki
> https://www.linkedin.com/in/koichidbms
>
>
> 2015-08-26 16:12 GMT+09:00 ssoorruu <sso...@gm...>:
>
>> Dear fellow PGXC enthusiasts,
>>
>> Good day and I hope you're all doing well, especially with Postgres-XC :)
>>
>> I have job to deploy Postgres-XC cluster replication using DRBD, and
>> cluster resource manager using Corosync-Pacemaker.
>> I've followed the tutorial from this link:
>>
>> https://www.howtoforge.com/how-to-set-up-an-active-passive-postgresql-cluster-with-pacemaker-corosync-and-drbd-centos-5.5
>>
>> But I cannot understand how to configure a Corosync resource for
>> Postgres-XC.
>>
>> Does anyone can give me tutorial on how to do Postgres-XC with
>> Corosync-Pacemaker?
>>
>> Very appreciate and thank you in advance.
>>
>>
>> Regards,
>> FattahRozzaq
>>
>>
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