Re: Rename max_parallel_degree?

On Sat, Oct 1, 2016 at 1:23 AM, Julien Rouhaud
<julien(dot)rouhaud(at)dalibo(dot)com> wrote:
> On 23/09/2016 21:10, Robert Haas wrote:
>> On Fri, Sep 23, 2016 at 8:54 AM, Peter Eisentraut
>> <peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
>>> On 9/20/16 4:07 PM, Robert Haas wrote:
>>>> No, I'm assuming that the classes would be built-in. A string tag
>>>> seems like over-engineering to me, particularly because the postmaster
>>>> needs to switch on the tag, and we need to be very careful about the
>>>> degree to which the postmaster trusts the contents of shared memory.
>>>
>>> I'm hoping that we can come up with something that extensions can
>>> participate in, without the core having to know ahead of time what those
>>> extensions are or how they would be categorized.
>>>
>>> My vision is something like
>>>
>>> max_processes = 512 # requires restart
>>>
>>> process_allowances = 'connection:300 superuser:10 autovacuum:10
>>> parallel:30 replication:10 someextension:20 someotherextension:20'
>>> # does not require restart
>>
>> I don't think it's going to be very practical to allow extensions to
>> participate in the mechanism because there have to be a finite number
>> of slots that is known at the time we create the main shared memory
>> segment.
>>
>> Also, it's really important that we don't add lots more surface area
>> for the postmaster to crash and burn.
>>
>
> It seems that there's no objection on Robert's initial proposal, so I'll
> try to implement it.
>
> I've already fixed every other issues mentioned upthread, but I'm facing
> a problem for this one. Assuming that the bgworker classes are supposed
> to be mutually exclusive, I don't see a simple and clean way to add such
> a check in SanityCheckBackgroundWorker(). Am I missing something
> obvious, or can someone give me some advice for this?

Okay, so marking it as returned with feedback is adapted? I have done
so but feel free to contradict me.
--
Michael