Re: -1 shutdown_timeout?

["Lin Jen-Shin (godfat)" <godfat@godfat.org>]

On Wed, Sep 23, 2015 at 4:05 PM, Eric Wong <e@80x24.org> wrote:
> "Lin Jen-Shin (godfat)" <godfat@godfat.org> wrote:
[...]
>> The timeout would be -1 after a few seconds, and then
>> it would only stop when those clients timeout at 60 seconds
>> (this is my assumption though, it would show a request was
>>  around 60 seconds from CommonLogger (assumption again)
>>  in the end, and yahns would quit gracefully)
>
> So your long request taking 60s is normal/expected?  yahns
> *should* be waiting that long (unless you send another SIGQUIT).
>
> You can probably set a shutdown_timeout >= 60s to quiet down the log
> messages.  It defaults to the highest client_timeout of all the apps
> running.

Looking at the code again (it's written long ago), yes you're right,
the polling would stop at 60s if there's no data available.
So I guess this is quite expected behaviour.

However instead of setting shutdown_timeout, I think I would probably
need to make the application know that the server is shutting down,
and stop right there instead of waiting for full 60 seconds.

Not sure if I could do this without talking to yahns directly...

>> I looked around the code, which should be:
>>
>>   def dropping(fdmap)
>>     if drop_acceptors[0] || fdmap.size > 0
>>       timeout = @shutdown_expire < Yahns.now ? -1 : @shutdown_timeout
>>       fdmap.desperate_expire(timeout)
>>       true
>>     else
>>       false
>>     end
>>   end
>>
>> While Yahns.now would get growing, I don't really understand why
>> it's written like this? Is this intentional? If so, how could I force
>> yahns shut those clients down in this case?
>
> Rereading the code, it seems intentional and correct.  Setting the -1
> timeout, means the shutdown_timeout has expired.  yahns will not raise
> cross-thread exceptions or signals to interrupt apps, so I guess the use
> of the word "desperate" is a misnomer.
>
> Admittedly, the shutdown code is a bit hairy and it took me to a bit to
> fix some of the race conditions back in 2013.

Understood now. Thank you!