Re: [Postgres-xc-general] HA features interrogations

[鈴木 幸市 <ko...@in...>]

Again, XC’s first goal is read/write scale out and parallel transaction processing among the nodes.    HA feature should be a separate solution combined with other failure handling with Corosync, for example.

Thank you;
---
Koichi Suzuki

2014/05/01 12:02、Tim Uckun <tim...@gm...<mailto:tim...@gm...>> のメール：

If pgxc could distribute the shards in a redundant fashion across the storage nodes I think it would go a very long way to make pgxc a very good HA solution.  If a storage node goes down then other nodes can serve the same shards and when a node is brought back up shards could be distributed to it.

Elasticsearch and other data stores use a similar strategy.


On Thu, May 1, 2014 at 1:11 PM, 鈴木 幸市 <ko...@in...<mailto:ko...@in...>> wrote:
It is just like PostgreSQL slave does not work as a master without explicit promote operation.

XC provides features for HA configuration but it does not provide HA feature by itself.   It is also similar to PG.   HA feature cannot be configured only within XC.   It needs much more, for example, hardware, network, and storage monitoring, failover and virtual IP.

At present this is why XC (and I believe PG as well) provides fundamental feature but not total HA solution.

This can be changed in the future though.

Pgxc_ctl provides simple way to start everything and monitor if everything is working, as well as simple manual failover mechanism.

Regards;
---
Koichi Suzuki

2014/04/30 23:54、Thibault Marquand <thi...@ec...<mailto:thi...@ec...>> のメール：

> Hi,
> I am setting up a High Availability (HA) architecture and I use PG-XC.
> Thank you very much for your work, it works fine and you are the only
> one active project for synchronous multi master replication.
>
> I don't understand why GTM proxies and GTM standby don't
> reconnect/promote themselves in case of GTM crash.
> At the moment, I use shell script to do this but I am not enthusiast
> with this because of maintenance trouble in future.
> Is there any reason of this lack of automation ?
>
> Still about HA feature, I realized that when all cluster start, if GTM
> doesn't work neither does GTM standby. Obviously database doesn't work
> in that case.
> I also made a script to handle this situation and change GTM standby
> config in order to transform it in GTM before starting. (Not using
> promote command, only changing configuration file). Maybe I missed
> something to make it work ? If not, could it be a new feature for future
> release ?
>
> You can find my script on my puppet module for postgres-xc :
> https://forge.puppetlabs.com/echoes/postgres_xc or
> https://github.com/echoes-tech/puppet-postgres_xc.
>
> Best regards,
> Thibault Marquand
>
> ------------------------------------------------------------------------------
> "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE
> Instantly run your Selenium tests across 300+ browser/OS combos.  Get
> unparalleled scalability from the best Selenium testing platform available.
> Simple to use. Nothing to install. Get started now for free."
> http://p.sf.net/sfu/SauceLabs
> _______________________________________________
> Postgres-xc-general mailing list
> Pos...@li...<mailto:Pos...@li...>
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-general
>

------------------------------------------------------------------------------
"Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE
Instantly run your Selenium tests across 300+ browser/OS combos.  Get
unparalleled scalability from the best Selenium testing platform available.
Simple to use. Nothing to install. Get started now for free."
http://p.sf.net/sfu/SauceLabs
_______________________________________________
Postgres-xc-general mailing list
Pos...@li...<mailto:Pos...@li...>
https://lists.sourceforge.net/lists/listinfo/postgres-xc-general