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Date:      Fri, 10 Apr 2015 11:01:44 +0200 (CEST)
From:      Raimund Sacherer <rs@logitravel.com>
To:        opendaddy@hushmail.com
Cc:        freebsd-questions@freebsd.org
Subject:   Re: Initial request to server extremely slow after longer periods of inactivity
Message-ID:  <369199529.123430074.1428656504549.JavaMail.zimbra@logitravel.com>
In-Reply-To: <20150409185801.1B1E9401E3@smtp.hushmail.com>
References:  <20150409034121.7D7C720395@smtp.hushmail.com> <CADqw_gL6b4fYyda9GzKt4BGv=d=sASttf4bp2_W%2B6JnuKQUCjg@mail.gmail.com> <20150409113928.EE31F401E4@smtp.hushmail.com> <CADqw_gK8-bxeNTYw4ATQnSM-w0iNBVWma83hMScdbsCwzEGxEw@mail.gmail.com> <20150409185801.1B1E9401E3@smtp.hushmail.com>

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----- Original Message -----=20

> From: opendaddy@hushmail.com
> To: "Michael Schuster" <michaelsprivate@gmail.com>, terje@elde.net,
> freebsd-questions@freebsd.org
> Sent: Thursday, April 9, 2015 8:58:00 PM
> Subject: Re: Initial request to server extremely slow after longer period=
s of
> inactivity

> It's probably not my DNS. From the NSD mailinglist:

> > On 9. april 2015 at 6:49 PM, "Ond=C5=99ej Sur=C3=BD" <ondrej@sury.org> =
wrote:
> >
> > if you run the daemon in any environment that is resource starved and
> > the process(es) gets swapped than anything will be slow on first reques=
t
> > after period of inactivity. Not just NSD and not just any DNS server,
> > but anything...

> I read somewhere that some people use a cron script to send a request to =
the
> webserver every so often. Is this something that everybody does but that
> I've somehow missed? Does it have a name?

> Thanks!

> O.D.

Hi,=20

we have quite a few unix servers around and I am unfamiliar with a cron-set=
up just to keep some sort of connectivity going.=20

First I would check the /etc/resolv.conf, if you want post it.=20

Then what I would do in your case is open a few ssh sessions, run top with =
cpu focus in one, top with IO focus in another and in a third i would take =
a tcpdump written to a file. Maybe another session with vmstat to check on =
pagin/pageout, etc.=20

Then I'd wait the appropriate amount of time and try a web connection, if i=
t takes long, I'l check the top's if there is something going on (lot's of =
CPU, lot's of IO, pages etc.) and check the tcpdump in wireshark to see if =
there are problematic DNS queries which maybe are timing out, etc.=20

That should cover the bases ... Maybe you are on some sort of cheap VPS ser=
vice which has resources severely over-commited and maybe your whole system=
 has to "wake up" ... but this is a very far-fetched scenario.=20

Best=20
Ray=20




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