Re: multi-install PostgresNode fails with older postgres versions - Mailing list pgsql-hackers

On 4/17/21 12:31 PM, Andrew Dunstan wrote:
> On 4/12/21 10:57 AM, Jehan-Guillaume de Rorthais wrote:
>> On Mon, 12 Apr 2021 09:52:24 -0400
>> Andrew Dunstan <andrew@dunslane.net> wrote:
>>
>>> On 4/12/21 8:59 AM, Jehan-Guillaume de Rorthais wrote:
>>>> Hi,
>>>>
>>>> On Wed, 7 Apr 2021 20:07:41 +0200
>>>> Jehan-Guillaume de Rorthais <jgdr@dalibo.com> wrote:
>>>> [...]  
>>>>>>> Let me know if it worth that I work on an official patch.      
>>>>>> Let's give it a try ...    
>>>>> OK  
>>>> So, as promised, here is my take to port my previous work on PostgreSQL
>>>> source tree.
>>>>
>>>> Make check pass with no errors. The new class probably deserve some own TAP
>>>> tests.
>>>>
>>>> Note that I added a PostgresVersion class for easier and cleaner version
>>>> comparisons. This could be an interesting take away no matter what.
>>>>
>>>> I still have some more ideas to cleanup, revamp and extend the base class,
>>>> but I prefer to go incremental to keep things review-ability.
>>>>  
>>> Thanks for this. We have been working somewhat on parallel lines. With
>>> your permission I'm going to take some of what you've done and
>>> incorporate it in the patch I'm working on.
>> The current context makes my weeks difficult to plan and quite chaotic, that's
>> why it took me some days to produce the patch I promised.
>>
>> I'm fine with working with a common base code, thanks. Feel free to merge both
>> code, we'll trade patches during review. However, I'm not sure what is the
>> status of your patch, so I can not judge what would be the easier way to
>> incorporate. Mine is tested down to 9.1 (9.0 was meaningless because of lack of
>> pg_stat_replication) with:
>>
>> * get_new_node
>> * init(allows_streaming => 1)
>> * start
>> * stop
>> * backup
>> * init_from_backup
>> * wait_for_catchup
>> * command_checks_all
>>
>> Note the various changes in my init() and new method allow_streaming(), etc.
>>
>> FYI (to avoid duplicate work), the next step on my todo was to produce some
>> meaningful tap tests to prove the class.
>>
>>> A PostgresVersion class is a good idea - I was already contemplating
>>> something of the kind.
>> Thanks!
>>
>
> OK, here is more WIP on this item. I have drawn substantially on Mark's
> and Jehan-Guillaime's work, but it doesn't really resemble either, and I
> take full responsibility for it.
>
> The guiding principles have been:
>
> . avoid doing version tests, or capability tests which are the moral
> equivalent, and rely instead on pure overloading.
>
> . avoid overriding large pieces of code.
>
>
> The last has involved breaking up some large subroutines (like init)
> into pieces which can more sensibly be overridden. Breaking them up
> isn't a bad thing to do anyway.
>
> There is a new PostgresVersion object, but it's deliberately very
> minimal. Since we're not doing version tests we don't need more complex
> routines.
>
>


I should have also attached my test program - here it is. Also, I have
been testing with the binaries which I've published here:
<https://gitlab.com/adunstan/pg-old-bin> along with some saved by my
buildfarm animal.


cheers


andrew


--
Andrew Dunstan
EDB: https://www.enterprisedb.com