default resource limits

I wrote:

>
>
> Tom Lane wrote:
>
>> Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
>>
>>
>>> Nearly everyone seems to agree that the default for max_fsm_pages is
>>> woefully low, so I would like to have the default for this set
>>> unconditionally to 200,000 rather than 20,000. The cost would be
>>> just over 1Mb of shared memory, if the docs are correct.
>>> Alternatively, we could put this into the mix that is calculated by
>>> initdb, scaling it linearly with shared_buffers (but with the
>>> default still at 200,000).
>>>
>>
>>
>>
>>
>>> I would also like to propose a more modest increase in
>>> max_connections and shared_buffers by a factor of 3.
>>>
>>
>>
>> I don't mind having initdb try larger values to see if they work, but
>> if you are suggesting that we try to force adoption of larger settings
>> I'll resist it.
>>
>>
>
> OK, works for me. The only thing I suggested might be set in stone was
> max_fsm_pages; I always envisioned the others being tested as now by
> initdb.
>
>> "Factor of three" seems mighty weird. The existing numbers (100 and
>> 1000)
>> at least have the defensibility of being round.
>>
>>
>>
>>
>
> What numbers would you like? If what I suggested seems odd, how about
> targets of 400 connections, 4000 shared_buffers and 200,000
> max_fsm_pages?
>
>

Here's a patch that does what I had in mind. On my modest workstation it
tops out at 400 connections and 2500/125000
shared_buffers/max_fsm_pages. An idle postmaster with these settings
consumed less than 4% of the 380Mb of memory, according to top, making
it still dwarfed by X, mozilla, apache and amavisd among other memory hogs.

Comments welcome.

cheers

andrew