[pgpool-general: 8213] Re: Pgpool Memory Requirement

[Nikolay Mastilo (HM)]

Ok, thanks a lot!

Regards,
    Nikola

10.06.2022 3:21, Bo Peng пишет:
> Hello,
>
>> Hello Bo,
>>
>> Thanks for your reply.
>>
>> Could you describe the formula by which the calculation is made in your
>> letter.
>> Where is the Shared Memory calculation here and where is the Processing
>> Memory.
> If your settings are:
>
>      num_init_children = 1000
>      max_pool=1
>
> Shared memory requirement (in mega bytes) = 10 + 1000 * 1 * 0.02 = 30MB
> Process memory requirement in total (in mega bytes) = 1000 * 0.16 = 160MB
>
> The requried memory is: 30MB + 160MB = 190MB
>
>> On 09.06.2022 17:05, Bo Peng wrote:
>>> Hello,
>>>
>>>> Pgpool works as load balancer in Kubernetes with 3 replicas. Docker
>>>> image pgpool/pgpool:4.2.2 is used.
>>>>
>>>> The section "7.1.1. Memory Requirement" of Pgpool documentation
>>>> specifies an amount of memory is required.
>>>>
>>>> According to formulas there if I need 1000 of num_init_children with
>>>> max_pool=1 , the amount of Shared Memory should be
>>>>
>>>> 1000*1*17408 Bytes = 17 MB. That's not a lot for Shared Memory.
>>>>
>>>> In addition  Process Memory is calculated as num_init_children * 5 MB.
>>>> In my case it reaches 5000MB or 5GB.
>>>>
>>>> My question is:
>>>> Should we assign such an amount of memory for the pod in k8s in which
>>>> the Pgpool docker image works, given that we use Pgpool exclusively as a
>>>> load balancer?
>>> Sorry. There was a bug in the document "Memory Requirement" section.
>>>
>>> It's fixed in the following commit:
>>> https://git.postgresql.org/gitweb/?p=pgpool2.git;a=commit;h=2b0f513430bab8b1d7898291638b335e8f04a76d
>>>
>>> Let me answer your question.
>>>
>>> If you settings is:
>>>
>>>     num_init_children = 1000
>>>     max_pool=1
>>>
>>> The requried memory is:
>>>
>>>     10 + 1000 * 1 * 0.02  + 1000 * 0.16 = 30MB + 160MB = 190MB
>>>
>>> Best regards,
>