Re: [Dime] [dime] #45: Why is a validity duration of 0 disallowed?

Steve Donovan <srdonovan@usdonovans.com> Thu, 13 February 2014 12:15 UTC

Return-Path: <srdonovan@usdonovans.com>
X-Original-To: dime@ietfa.amsl.com
Delivered-To: dime@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1E0CC1A0200 for <dime@ietfa.amsl.com>; Thu, 13 Feb 2014 04:15:53 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.12
X-Spam-Level:
X-Spam-Status: No, score=-1.12 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HTML_MESSAGE=0.001, SPF_NEUTRAL=0.779] autolearn=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id m89jVGYliLEC for <dime@ietfa.amsl.com>; Thu, 13 Feb 2014 04:15:48 -0800 (PST)
Received: from biz131.inmotionhosting.com (biz131.inmotionhosting.com [173.247.247.114]) by ietfa.amsl.com (Postfix) with ESMTP id F32361A01F8 for <dime@ietf.org>; Thu, 13 Feb 2014 04:15:47 -0800 (PST)
Received: from cpe-76-187-100-94.tx.res.rr.com ([76.187.100.94]:53679 helo=SDmac.local) by biz131.inmotionhosting.com with esmtpsa (TLSv1:DHE-RSA-AES128-SHA:128) (Exim 4.82) (envelope-from <srdonovan@usdonovans.com>) id 1WDvCb-0004jO-Vj for dime@ietf.org; Thu, 13 Feb 2014 04:15:46 -0800
Message-ID: <52FCB76E.6020202@usdonovans.com>
Date: Thu, 13 Feb 2014 06:15:42 -0600
From: Steve Donovan <srdonovan@usdonovans.com>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Thunderbird/24.3.0
MIME-Version: 1.0
To: dime@ietf.org
References: <057.2153d3a0ed57933cb4ec7468d82db1d9@trac.tools.ietf.org> <61BD40D6-20C5-4F47-876D-27E2D323C241@nostrum.com> <97EF76DD-0AAA-458C-90E4-A16443E5B06B@gmail.com> <F8DA59C4-65A5-44B5-8DD9-AEDA8F04C32D@nostrum.com> <087A34937E64E74E848732CFF8354B9209772FEF@ESESSMB101.ericsson.se> <087A34937E64E74E848732CFF8354B9209774086@ESESSMB101.ericsson.se> <5BCBA1FC2B7F0B4C9D935572D9000668151B2F04@DEMUMBX014.nsn-intra.net> <087A34937E64E74E848732CFF8354B9209774131@ESESSMB101.ericsson.se> <5BCBA1FC2B7F0B4C9D935572D9000668151B2F51@DEMUMBX014.nsn-intra.net> <E194C2E18676714DACA9C3A2516265D202664851@FR712WXCHMBA11.zeu.alcatel-lucent.com> <A9CA33BB78081F478946E4F34BF9AAA014D6C2C9@xmb-rcd-x10.cisco.com> <5BCBA1FC2B7F0B4C9D935572D9000668151B3207@DEMUMBX014.nsn-intra.net> <E194C2E18676714DACA9C3A2516265D2026649BC@FR712WXCHMBA11.zeu.alcatel-lucent.com> <087A34937E64E74E848732CFF8354B9209774896@ESESSMB101.ericsson.se> <E194C2E18676714DACA9C3A2516265D2026649F8@FR712WXCHMBA11.zeu.alcatel-lucent.com>
In-Reply-To: <E194C2E18676714DACA9C3A2516265D2026649F8@FR712WXCHMBA11.zeu.alcatel-lucent.com>
Content-Type: multipart/alternative; boundary="------------050605040907030601020606"
X-OutGoing-Spam-Status: No, score=-2.9
X-AntiAbuse: This header was added to track abuse, please include it with any abuse report
X-AntiAbuse: Primary Hostname - biz131.inmotionhosting.com
X-AntiAbuse: Original Domain - ietf.org
X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12]
X-AntiAbuse: Sender Address Domain - usdonovans.com
X-Get-Message-Sender-Via: biz131.inmotionhosting.com: authenticated_id: srdonovan@usdonovans.com
Subject: Re: [Dime] [dime] #45: Why is a validity duration of 0 disallowed?
X-BeenThere: dime@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Diameter Maintanence and Extentions Working Group <dime.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dime>, <mailto:dime-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/dime/>
List-Post: <mailto:dime@ietf.org>
List-Help: <mailto:dime-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dime>, <mailto:dime-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 13 Feb 2014 12:15:53 -0000

JJ,

Why does the reacting node need to send a reduction percentage of zero
to determine if it is stable?  Can't the reacting node just do its
normal checking for overload after sending the validity period of zero? 
If it finds the need for reduction of traffic, it can just send a new
overload report.

Steve

On 2/13/14 4:43 AM, TROTTIN, JEAN-JACQUES (JEAN-JACQUES) wrote:
>
> Hi MCruz
>
>  
>
> AS  Ben proposed, and I agree,   value of zero (0) for the Validity
> period indicates that an existing overload condition has ended and
> that the reporting node is in a stable condition.
>
> An important word is "stable".
>
>  
>
> When the traffic peak on client side having created the overload
> decreases,   the reporting node progressively diminishes the % traffic
> reduction in OLRs it sends  towards clients taking care to minimize
> the possible oscillations. At a certain time ,  server will consider
> that it can indicate no traffic reduction to clients. Then is it
> stable?  there may be different implementation dependent  ways for the
> server to decide the situation is stable;  one is to send 0% in OLRs
> and wait a certain number of seconds (not 24 hours) to check if
> situation is stable  and then put the validity timer to 0 (or leaves
> the expiry timer  expire). I do not see why to forbid this  way to
> test the stable condition.
>
>  
>
> So the end of overload condition, as Ben proposed,  can remain ONLY
> based on Validity  duration value 0 (or timer expiry), not on the
> value 0 of the % reduction (so a bit different from Nirav statement,
> but in line with Ulrich comment) . The value 0% of the traffic
> reduction is not forbidden as a possible  way to check the stability
> condition .
>
>  
>
> Best regards
>
>  
>
> JJacques
>
>  
>
>  
>
> *De :*DiME [mailto:dime-bounces@ietf.org] *De la part de* Maria Cruz
> Bartolome
> *Envoyé :* jeudi 13 février 2014 10:56
> *À :* dime@ietf.org list
> *Objet :* Re: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> Hello all,
>
>  
>
> I think proposal to use just Validity-Duration=0 to end overload
> mainly has the intention to simplify and avoid the checks you just
> listed below.
>
> If we allow both, it means that the case Ulrich mentioned is valid,
> and even with 0% reduction OLR info cannot be deleted until Validity
> time expires, even we could receive a new OLR in sequence. Even, the
> reporting needs still to keep Validity timer on for this OLR.
>
> I think this does not provide any added value but simply makes things
> a bit more complex. What could be the reason to keep 0% reduction but
> a Validity of a few hours (e.g.)?
>
>  
>
> Best regards
>
> /MCruz
>
>  
>
>  
>
> *From:*DiME [mailto:dime-bounces@ietf.org] *On Behalf Of *TROTTIN,
> JEAN-JACQUES (JEAN-JACQUES)
> *Sent:* jueves, 13 de febrero de 2014 10:24
> *To:* dime@ietf.org <mailto:dime@ietf.org> list
> *Subject:* Re: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> I am OK with Ulrich
>
>  
>
> JJacques
>
>  
>
>  
>
> *De :*Wiehe, Ulrich (NSN - DE/Munich) [mailto:ulrich.wiehe@nsn.com]
> *Envoyé :* jeudi 13 février 2014 09:56
> *À :* ext Nirav Salot (nsalot); TROTTIN, JEAN-JACQUES (JEAN-JACQUES);
> dime@ietf.org <mailto:dime@ietf.org> list
> *Objet :* RE: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> I also agree with the principle.
>
>  
>
> One minor clarification:
>
> 0%-reduction with non-zero validity period is valid but validity
> period cannot be ignored: as long as not expired the sequence number
> needs to be stored for future checking; once expired, sequence number
> must not be used for future checking.
>
>  
>
> Ulrich
>
>  
>
> *From:*DiME [mailto:dime-bounces@ietf.org] *On Behalf Of *ext Nirav
> Salot (nsalot)
> *Sent:* Thursday, February 13, 2014 4:11 AM
> *To:* TROTTIN, JEAN-JACQUES (JEAN-JACQUES); dime@ietf.org
> <mailto:dime@ietf.org> list
> *Subject:* Re: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> I also tend to agree with JJ below.
>
> Unless there is a strong reason, no point in forbidding the use of 0%
> reduction -- which can also indicate end of overload condition.
>
>  
>
> May be we can clarify that 0% reduction and/or 0 validity period
> indicates end of overload. In my view, both are valid for the use,
> individually and together. So,
>
> -          0 reduction, non-zero validity period => Valid. The
> reacting node can ignore the validity period if reduction is 0.
>
> -          Non-zero reduction, 0 validity period => Valid. The
> reacting node can ignore the reduction if validity period is 0.
>
> -          0 reduction, 0 validity period => Valid as well. Generally,
> this is what the reporting node will use to indicate the end of
> overload condition.
>
>  
>
> Regards,
>
> Nirav.
>
>  
>
> *From:*DiME [mailto:dime-bounces@ietf.org] *On Behalf Of *TROTTIN,
> JEAN-JACQUES (JEAN-JACQUES)
> *Sent:* Thursday, February 13, 2014 2:18 AM
> *To:* dime@ietf.org <mailto:dime@ietf.org> list
> *Subject:* Re: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> Dear all
>
>  
>
> On this ticket,  I agree on Ben's  proposal  to use the Validity
> period of 0 to indicate the end of overload.
>
> But about the value of 0% reduction why to forbid it ?
>
>  
>
> In the process to  return to normal traffic conditions, the  server
> still sending OLR eg with  5% reduction    will consider to no request
> anymore traffic reduction but without being yet sure if  it will be
>  stable (end of overload condition as Ben reminded means stable
>  situation without traffic reduction ) , so server  can send 0%
> reduction OLR  but with a validity duration different from 0.
>
> Otherwise it has to  use 1% throttling to check stability and if
> traffic with the client is 1000 request per second this means 10
> requests throttled per second which should not be throttled.
>
> In addition, we do not need to handle the 0% reduction  as an error
> case (cf Mcruz mail)
>
>  
>
> Best regards
>
>  
>
> JJacques
>
>  
>
>  
>
> *De :*DiME [mailto:dime-bounces@ietf.org] *De la part de* Wiehe,
> Ulrich (NSN - DE/Munich)
> *Envoyé :* mercredi 12 février 2014 10:22
> *À :* ext Maria Cruz Bartolome; dime@ietf.org <mailto:dime@ietf.org> list
> *Objet :* Re: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> Thank you for the clarification.
>
> I agree.
>
>  
>
> *From:*DiME [mailto:dime-bounces@ietf.org] *On Behalf Of *ext Maria
> Cruz Bartolome
> *Sent:* Wednesday, February 12, 2014 10:13 AM
> *To:* dime@ietf.org <mailto:dime@ietf.org> list
> *Subject:* Re: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> Dear Ulrich, all,
>
>  
>
> The proposal was to use OC-Validity-Duration AVP =0 to indicate end of
> overload, since this could be generally applied to any algorithm.
>
> Then, Reduction-Percentage = 0 should be considered as invalid.
>
> I found this reasonable.
>
>  
>
> Best regards
>
> /MCruz
>
>  
>
>  
>
> *From:*Wiehe, Ulrich (NSN - DE/Munich) [mailto:ulrich.wiehe@nsn.com]
> *Sent:* miércoles, 12 de febrero de 2014 9:57
> *To:* Maria Cruz Bartolome; dime@ietf.org <mailto:dime@ietf.org> list
> *Subject:* RE: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> I'm confused,
>
>  
>
> I thought that people were in favour of allowing 0 to indicate end of
> overload.
>
>  
>
> Ulrich
>
>  
>
> *From:*DiME [mailto:dime-bounces@ietf.org] *On Behalf Of *ext Maria
> Cruz Bartolome
> *Sent:* Wednesday, February 12, 2014 9:44 AM
> *To:* dime@ietf.org <mailto:dime@ietf.org> list
> *Subject:* Re: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> Ben, all,
>
>  
>
> This comment affects as well clause 5.5.2:
>
>  
>
>    value == 0
>
>  
>
>       Indicates explicitly the end of overload condition and the
>
>       reacting node SHOULD NOT apply the traffic abatement algorithm
>
>       procedures anymore for the given reporting node (or realm).
>
>  
>
> This should be modified to explain this value is not valid and what is
> the expected behavior (i.e. it is discarded).
>
>  
>
> Best regards
>
> /MCruz
>
>  
>
> *From:*DiME [mailto:dime-bounces@ietf.org] *On Behalf Of *Maria Cruz
> Bartolome
> *Sent:* martes, 11 de febrero de 2014 14:54
> *To:* dime@ietf.org <mailto:dime@ietf.org> list
> *Subject:* Re: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> Ben,
>
>  
>
> This approach sounds reasonable to me.
>
> But I would like to clarify what should be the behavior if a
> Reduction-Percentage=0 is received. This is an invalid value, then I
> presume it should be discarded by client.
>
>  
>
> Regards
>
> /MCruz
>
>  
>
> *From:*DiME [mailto:dime-bounces@ietf.org] *On Behalf Of *Ben Campbell
> *Sent:* martes, 11 de febrero de 2014 0:56
> *To:* Jouni Korhonen
> *Cc:* dime@ietf.org <mailto:dime@ietf.org> list;
> draft-docdt-dime-ovli@tools.ietf.org
> <mailto:draft-docdt-dime-ovli@tools.ietf.org>
> *Subject:* Re: [Dime] [dime] #45: Why is a validity duration of 0
> disallowed?
>
>  
>
> So, here's some proposed text. (intentionally ignoring the related
> discussion about handling invalid values):
>
>  
>
> Section 4.5, first paragraph, last 2 sentences:
>
>  
>
> Old:
>
>  
>
> Validity duration values 0 (i.e., 0 seconds) and above 86400 (i.e., 24
> hours) MUST NOT be used. Invalid validity duration values are treated
> as if the OC-Validity-Duration AVP were not present.
>
>  
>
> New:
>
>  
>
> Validity duration values above 86400 MUST NOT be used. Invalid
> validity duration values are treated as if the OC-Validity-Duration
> AVP were not present. A value of zero (0) indicates that an existing
> overload condition has ended and that the reporting node is in a
> stable condition.
>
>  
>
> Section 4.7, 2nd paragraph:
>
>  
>
> Old:
>
>  
>
>  The value of the Reduction-Percentage AVP is between one (1) and one
> hundred (100).  Values greater than 100 are interpreted as 100.  The
> value of 100 means that no traffic is expected, i.e. the reporting
> node is under a severe load and ceases to process any new messages.
> The Reduction-Percentage AVP MUST be present in an overload report
> that uses the default abatement algorithm.
>
>  
>
>     Note that there is no zero (0) value defined for the
>     Reduction-Percentage AVP. A zero value would logically indicate
>     that no overload abatement is requested. Instead, reporting nodes
>     use a OC-Validity-Duration AVP value of zero (0) to indicate the
>     end of an overload condition. [Section 4.5]
>
>  
>
>  
>
>  
>
>  
>
>  
>
>
> On Feb 10, 2014, at 4:12 PM, Jouni Korhonen <jouni.nospam@gmail.com
> <mailto:jouni.nospam@gmail.com>> wrote:
>
> Just post it here.
>
>
>
> On Feb 10, 2014, at 6:25 PM, Ben Campbell <ben@nostrum.com
> <mailto:ben@nostrum.com>> wrote:
>
> Okay. Does that mean we should assign the issue to me in the tracker?
>
> On Feb 10, 2014, at 10:06 AM, Jouni Korhonen <jouni.nospam@gmail.com
> <mailto:jouni.nospam@gmail.com>> wrote:
>
>
> Ben,
>
> Propose some text and we can see how it fits in.
>
> - Jouni
>
>
> On Feb 10, 2014, at 5:53 PM, Ben Campbell <ben@nostrum.com
> <mailto:ben@nostrum.com>> wrote:
>
>
> On Feb 10, 2014, at 5:12 AM, Jouni Korhonen <jouni.nospam@gmail.com
> <mailto:jouni.nospam@gmail.com>> wrote:
>
>
> On Feb 7, 2014, at 11:54 PM, dime issue tracker
> <trac+dime@trac.tools.ietf.org <mailto:trac+dime@trac.tools.ietf.org>>
> wrote:
>
> #45: Why is a validity duration of 0 disallowed?
>
> Section 4.5 disallows a validity duration of zero. Why do we want to
> disallow that? It would allow a quick way of ending any existing overload
> condition without worrying about the semantics of the abatement algorithm.
> (We currently use a reduction percentage of zero to end an overload
> condition--but that's specific to the loss algorithm and might not make
> sense for all future ones.)
>
>
> Right. Avoiding two ways of ending overload condition was the reason.
> I am OK to have validity duration 0 as an additional method ending the
> overload condition based on the reasoning above.
>
>
> I would go further and make duration 0 the _preferred_ way, for two
> reasons:
>
> 1) It's algorithm independent. (reduction-percentage of 0 is specific
> to algorithms that use reduction percentage.)
>
> 2) Explicit signaling of the end of an overload condition becomes
> semantically identical to the expiration of an overload condition.
> This allows a simpler implementation.
>
>  
>
>  
>
>
> _______________________________________________
> DiME mailing list
> DiME@ietf.org <mailto:DiME@ietf.org>
> https://www.ietf.org/mailman/listinfo/dime
>
>  
>
>
>
> _______________________________________________
> DiME mailing list
> DiME@ietf.org
> https://www.ietf.org/mailman/listinfo/dime