On 12/6/21 4:58 PM, Yann Ylavic wrote:
> On Mon, Dec 6, 2021 at 3:27 PM Yann Ylavic <ylavic....@gmail.com> wrote:
>>
>> On Mon, Dec 6, 2021 at 1:53 PM Ruediger Pluem <rpl...@apache.org> wrote:
>>>
>>> On 12/6/21 1:33 PM, Yann Ylavic wrote:
>>>>
>>>> How about (modulo brain fart):
>>>> const int N = 1; /* or 2, 3, 4.. */
>>>> int avail_daemons = server_limit - retained->total_daemons;
>>>> int have_room_for_N_restarts = (avail_daemons / N >=
>>>> active_daemons_limit);
>>>> int inactive_daemons = retained->total_daemons -
>>>> retained->active_daemons;
>>>> int do_kill = (have_room_for_N_restarts || inactive_daemons == 0);
>>>> if (do_kill) {
>>>> ap_mpm_podx_signal(retained->buckets[child_bucket].pod,
>>>> AP_MPM_PODX_GRACEFUL);
>>>> }
>>>> else {
>>>> /* Wait for inactive_daemons to settle down */
>>>> }
>>>> ?
>>>>
>>>
>>> Not sure if it is worth it as I think that have_room_for_N_restarts will
>>> only rarely be true.
>>
>> You are right if "server_limit < 2 * active_daemons_limit" but I don't
>> think it's a "reasonable" configuration, I wouldn't mind serializing
>> kills (i.e. inactive_daemons == 0) in this case to avoid "Scoreboard
>> is full" issues on a "loady" restart, all the more with slow-to-exit
>> processes (asynchronous, huge timeouts connections). Scoreboard is
>> quite cheap in (shared-)memory space, "ServerLimit >= 5 *
>> active_daemons_limit" is not what will eat system memory..
>>
>> So if we take "N = server_limit / active_daemons_limit", the above
>> looks like something that could work for killing processes >
>> MaxSpareThreads faster (even though I don't find it necessarily
>> helpful personally) with a "reasonable" configuration.
>
> Argh no sorry for the babbling (we don't want to maintain N potential
> restarts all the time, one is enough, more is at the admin's
> discretion depending on the workflow..).
>
> If we want to stop killing processes to keep a reserve of
> active_daemons_limit for a potential graceful restart, the condition
> might be:
> int do_kill = (retained->total_daemons == retained->active_daemons
> || (server_limit - retained->total_daemons >
> active_daemons_limit));
>
> But after all it might not be your concern nor your priority..
This is fine. Maybe the large headroom is a good idea for people that complain
about the change in behavior and as you state, a
large scoreboard should not be too costly these days. Hence +1 to the
additional condition.
Regards
Rüdiger
