[ClusterLabs] Resource Agents: pgsql vs. pgsqlms

[Ede Wolf]

Just let me take this mail as a placeholder to thank you all very much 
for your rather fast replies!

Just wondering, besides implementation and documentation, is there an 
overview of features / percieved advantages of one over the other?

One is, the older ra is somewhat more timeproven, the other the 
language. Bash is realistic to read, perl probably not.

Since both documentations seem to not to be up to date, using those as a 
baseline may not be the most useful for a comparison. Now, if that's all 
there is, then be it.

Since this does not free us from actually testing both in a lab. But as 
we are rather new to this as well, we might not initally have the 
knowledge to evaluate both to its fullest.

Maybe we are missing or misjudging something that may come back later.
Of course, that is completely our responsibility, just trying to be 
prepared as well as possible beforehand

Thanks again

Ede

Am 11.07.24 um 10:38 schrieb Jehan-Guillaume de Rorthais:
> Hello Ede,
> 
> On Wed, 10 Jul 2024 19:18:26 +0200
> Ede Wolf <listac at nebelschwaden.de> wrote:
> 
>> […]
>> we are about to set up a postgresql 15 ha solution and since we already
>> have some experience with pacemaker, this seems the obvious route to go
>> first.
> 
> Indeed!
> 
>> What however is somewhat confusing are the available resource agents.
>> By default the pgsql agent is shipped, at least with debian and
>> SLES, that however has a copyright notice dating back to 2012.
> 
> I don't know for SLES, but PAF is shipped under Debian and RH/Rocky from
> official repositories as package "resource-agents-paf".
> 
>> Now, when trying to research postgres and pacemaker, most articles do
>> talk about PAF, or the pgsqlms resource.
>>
>> I have so far not been able to find the differences between both,
> 
> These are big differences between both agents. Just do some lab with both of
> them, you'll find the doc, pre-requisits, setup and management are quite
> different.
> 
>> and in case PAF is, for one reason or the other, the better or more up
>> to date solution, why is it not shipped by default? At least not with
>> debian or SLES15?
> 
> It is shipped, but not in the "resource-agents" package. This might be
> because PAF has been created outside of the clusterlabs repositories, but has
> then been accepted there after few years, but in its own repository.
> 
>> Since postgres ha is rather new to us and me having been lucky not
>> having had to deal with perl so far, just reading the agents
>> themselves does not really shed that much light on this issue.
>>
>> So in case there is some documentation on comparing these two, or some
>> experience, that would be really helpful
> 
> You might find this FAQ entry useful:
> 
> https://clusterlabs.github.io/PAF/FAQ.html#why-new-ra-for-postgresql
> 
> ++