From tranxene50 at openvz-diff-backups.fr  Sun Jun 14 02:31:46 2020
From: tranxene50 at openvz-diff-backups.fr (tranxene50)
Date: Sun, 14 Jun 2020 04:31:46 +0200
Subject: Caching OSM tiles - how to not overload backends?
Message-ID: <62cc477d-e27f-1ed0-bd16-06d4c7dd907f@openvz-diff-backups.fr>

Hello!

Please forgive my bad English, I live in France.

Summary: how to cache - with Varnish - Open Street Map PNG images 
without overloading OSM tiles servers?

The question seems related to Varnish backends and ".max_connections" 
parameter.

A far as I know, if ".max_connections" is reached for a backend, Varnish 
sends 503 http errors.

I understand the logic but would it be possible to queue these incoming 
requests and wait until the selected backend is really available?

backend a_tile????????????????? {
 ? .host???????????????????????? = "a.tile.openstreetmap.org";
 ? .port???????????????????????? = "80";
 ? .max_connections????????????? = 2;
}

If Varnish have, let's say 100 incoming requests in 1 second, how can I 
handle this "spike" without overloading the backend?

All my google searches were "dead ends" so I think the question is 
poorly formulated.

Note 1 : using [random|round_robin] directors could be a temporary solution
Note 2 : libvmod-dynamic is great but does not limit backend 
simultaneous connexions

Many thanks for your help!

-- 
tranxene50
tranxene50 at openvz-diff-backups.fr

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From info+varnish at shee.org  Mon Jun 15 12:28:42 2020
From: info+varnish at shee.org (info+varnish at shee.org)
Date: Mon, 15 Jun 2020 14:28:42 +0200
Subject: varnish node without gcc
Message-ID: <08628336a17c60faf98a8b4e6464b3f63cc85f30.camel@shee.org>

Hi,

is it possible to compile the final merged vcl configuration in a pre
step and then pushing it to the frontend nodes? So, no vcl config and 
gcc on the frontend. Just a bin blob and a restart of the service.

Can this "compile while restart" activity splitted into to seprated
ones? Is that possible?

--
Thanks,
Leon


From dridi at varni.sh  Mon Jun 15 13:24:41 2020
From: dridi at varni.sh (Dridi Boukelmoune)
Date: Mon, 15 Jun 2020 13:24:41 +0000
Subject: varnish node without gcc
In-Reply-To: <08628336a17c60faf98a8b4e6464b3f63cc85f30.camel@shee.org>
References: <08628336a17c60faf98a8b4e6464b3f63cc85f30.camel@shee.org>
Message-ID: <CABoVN9DgZPQAZWtrmJWD4G9h=MNqaD6-G1Y7a1f3CH=HXBxEUg@mail.gmail.com>

On Mon, Jun 15, 2020 at 12:29 PM <info+varnish at shee.org> wrote:
>
> Hi,
>
> is it possible to compile the final merged vcl configuration in a pre
> step and then pushing it to the frontend nodes? So, no vcl config and
> gcc on the frontend. Just a bin blob and a restart of the service.

It is technically possible to pass a blob around, but Varnish insists
on compiling VCL locally.

> Can this "compile while restart" activity splitted into to seprated
> ones? Is that possible?

There is no restart involved, VCL is meant to be loadable on the fly.

Dridi

From guillaume at varnish-software.com  Mon Jun 15 14:46:08 2020
From: guillaume at varnish-software.com (Guillaume Quintard)
Date: Mon, 15 Jun 2020 07:46:08 -0700
Subject: varnish node without gcc
In-Reply-To: <CABoVN9DgZPQAZWtrmJWD4G9h=MNqaD6-G1Y7a1f3CH=HXBxEUg@mail.gmail.com>
References: <08628336a17c60faf98a8b4e6464b3f63cc85f30.camel@shee.org>
 <CABoVN9DgZPQAZWtrmJWD4G9h=MNqaD6-G1Y7a1f3CH=HXBxEUg@mail.gmail.com>
Message-ID: <CAJ6ZYQw9_X6Fagd5WZVre9jMSZyzUMAnZXv9Og27Cxg_VqJ-Qg@mail.gmail.com>

Hi,

Just to add a detail here, you can have a look at "varnishadm param.show
cc_command" to see how varnish transforms the C into a shared object.

-- 
Guillaume Quintard


On Mon, Jun 15, 2020 at 6:26 AM Dridi Boukelmoune <dridi at varni.sh> wrote:

> On Mon, Jun 15, 2020 at 12:29 PM <info+varnish at shee.org> wrote:
> >
> > Hi,
> >
> > is it possible to compile the final merged vcl configuration in a pre
> > step and then pushing it to the frontend nodes? So, no vcl config and
> > gcc on the frontend. Just a bin blob and a restart of the service.
>
> It is technically possible to pass a blob around, but Varnish insists
> on compiling VCL locally.
>
> > Can this "compile while restart" activity splitted into to seprated
> > ones? Is that possible?
>
> There is no restart involved, VCL is meant to be loadable on the fly.
>
> Dridi
> _______________________________________________
> varnish-misc mailing list
> varnish-misc at varnish-cache.org
> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>
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From dridi at varni.sh  Mon Jun 15 18:00:05 2020
From: dridi at varni.sh (Dridi Boukelmoune)
Date: Mon, 15 Jun 2020 18:00:05 +0000
Subject: Caching OSM tiles - how to not overload backends?
In-Reply-To: <62cc477d-e27f-1ed0-bd16-06d4c7dd907f@openvz-diff-backups.fr>
References: <62cc477d-e27f-1ed0-bd16-06d4c7dd907f@openvz-diff-backups.fr>
Message-ID: <CABoVN9Bz-2r+Rx+zMPMb1dF3Brm3KC0jArxKvvh-wzH7aby=Fg@mail.gmail.com>

On Sun, Jun 14, 2020 at 2:32 AM tranxene50
<tranxene50 at openvz-diff-backups.fr> wrote:
>
> Hello!
>
> Please forgive my bad English, I live in France.
>
> Summary: how to cache - with Varnish - Open Street Map PNG images without overloading OSM tiles servers?
>
> The question seems related to Varnish backends and ".max_connections" parameter.
>
> A far as I know, if ".max_connections" is reached for a backend, Varnish sends 503 http errors.
>
> I understand the logic but would it be possible to queue these incoming requests and wait until the selected backend is really available?
>
> backend a_tile                  {
>   .host                         = "a.tile.openstreetmap.org";
>   .port                         = "80";
>   .max_connections              = 2;
> }
>
> If Varnish have, let's say 100 incoming requests in 1 second, how can I handle this "spike" without overloading the backend?
>
> All my google searches were "dead ends" so I think the question is poorly formulated.
>
> Note 1 : using [random|round_robin] directors could be a temporary solution
> Note 2 : libvmod-dynamic is great but does not limit backend simultaneous connexions
>
> Many thanks for your help!

Bonsoir,

Unfortunately we don't have any sort of queuing on the backend side,
so besides implementing your own backend transport from scratch in a
VMOD there is currently no solution.

Cordialement,
Dridi

From xavier at ccmbenchmark.com  Mon Jun 15 22:17:12 2020
From: xavier at ccmbenchmark.com (Xavier Leune)
Date: Tue, 16 Jun 2020 00:17:12 +0200
Subject: Caching OSM tiles - how to not overload backends?
In-Reply-To: <CABoVN9Bz-2r+Rx+zMPMb1dF3Brm3KC0jArxKvvh-wzH7aby=Fg@mail.gmail.com>
References: <62cc477d-e27f-1ed0-bd16-06d4c7dd907f@openvz-diff-backups.fr>
 <CABoVN9Bz-2r+Rx+zMPMb1dF3Brm3KC0jArxKvvh-wzH7aby=Fg@mail.gmail.com>
Message-ID: <CAMJmMZPsxZS=nNSW70yiCkWGPsVGxKDCX9FW4PON4TccYcXMug@mail.gmail.com>

Hello,

@tranxene50 if implementing a vmod can be very challenging, using haproxy
can be a great solution here. Please refer to this blog post:
https://www.haproxy.com/fr/blog/four-examples-of-haproxy-rate-limiting/ (or
in french ;)
https://www.haproxy.com/fr/blog/four-examples-of-haproxy-rate-limiting/ ).
The very first step is about setting a maximum connections number and a
queuing. Using haproxy as your backend would require low engineering and a
minimum overage.

Regards,

Le lun. 15 juin 2020 ? 20:02, Dridi Boukelmoune <dridi at varni.sh> a ?crit :

> On Sun, Jun 14, 2020 at 2:32 AM tranxene50
> <tranxene50 at openvz-diff-backups.fr> wrote:
> >
> > Hello!
> >
> > Please forgive my bad English, I live in France.
> >
> > Summary: how to cache - with Varnish - Open Street Map PNG images
> without overloading OSM tiles servers?
> >
> > The question seems related to Varnish backends and ".max_connections"
> parameter.
> >
> > A far as I know, if ".max_connections" is reached for a backend, Varnish
> sends 503 http errors.
> >
> > I understand the logic but would it be possible to queue these incoming
> requests and wait until the selected backend is really available?
> >
> > backend a_tile                  {
> >   .host                         = "a.tile.openstreetmap.org";
> >   .port                         = "80";
> >   .max_connections              = 2;
> > }
> >
> > If Varnish have, let's say 100 incoming requests in 1 second, how can I
> handle this "spike" without overloading the backend?
> >
> > All my google searches were "dead ends" so I think the question is
> poorly formulated.
> >
> > Note 1 : using [random|round_robin] directors could be a temporary
> solution
> > Note 2 : libvmod-dynamic is great but does not limit backend
> simultaneous connexions
> >
> > Many thanks for your help!
>
> Bonsoir,
>
> Unfortunately we don't have any sort of queuing on the backend side,
> so besides implementing your own backend transport from scratch in a
> VMOD there is currently no solution.
>
> Cordialement,
> Dridi
> _______________________________________________
> varnish-misc mailing list
> varnish-misc at varnish-cache.org
> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>
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From tranxene50 at openvz-diff-backups.fr  Tue Jun 16 22:21:22 2020
From: tranxene50 at openvz-diff-backups.fr (tranxene50)
Date: Wed, 17 Jun 2020 00:21:22 +0200
Subject: Caching OSM tiles - how to not overload backends?
In-Reply-To: <CAMJmMZPsxZS=nNSW70yiCkWGPsVGxKDCX9FW4PON4TccYcXMug@mail.gmail.com>
References: <62cc477d-e27f-1ed0-bd16-06d4c7dd907f@openvz-diff-backups.fr>
 <CABoVN9Bz-2r+Rx+zMPMb1dF3Brm3KC0jArxKvvh-wzH7aby=Fg@mail.gmail.com>
 <CAMJmMZPsxZS=nNSW70yiCkWGPsVGxKDCX9FW4PON4TccYcXMug@mail.gmail.com>
Message-ID: <3be01b29-b704-3af2-57a9-2e071f1170e0@openvz-diff-backups.fr>

Hello!

Many thanks for your answers! :-)

@Dridi:

You are right, writing a specific VMOD would be the ideal solution but 
unfortunately I am not qualified for the job. ^^

By the way, I would like to thank all the people who are working hard to 
enhance and maintain Varnish.

This software is absolutely awesome!

@Xavier:

Before considering HAProxy, I searched if quick and dirty hacks were 
possible with iptables to limit simultaneous connexions and tc to shape 
the traffic.

But, after a quick reading of the documentation of HAProxy, it became 
clear that - as you said - it is a reliable solution.

So, thanks the for the hint!

Have a great day!

Le 16/06/2020 ? 00:17, Xavier Leune a ?crit?:
> Hello,
>
> @tranxene50 if implementing a vmod can be very challenging, using 
> haproxy can be a great solution here. Please refer to this blog post: 
> https://www.haproxy.com/fr/blog/four-examples-of-haproxy-rate-limiting/?(or 
> in french ;) 
> https://www.haproxy.com/fr/blog/four-examples-of-haproxy-rate-limiting/?). 
> The very first step is about setting a maximum connections number and 
> a queuing. Using haproxy as your backend would require low engineering 
> and a minimum overage.
>
> Regards,
>
> Le?lun. 15 juin 2020 ??20:02, Dridi Boukelmoune <dridi at varni.sh> a ?crit?:
>
>
>     Bonsoir,
>
>     Unfortunately we don't have any sort of queuing on the backend side,
>     so besides implementing your own backend transport from scratch in a
>     VMOD there is currently no solution.
>
>     Cordialement,
>     Dridi
>
>     On Sun, Jun 14, 2020 at 2:32 AM tranxene50
>     <tranxene50 at openvz-diff-backups.fr
>     <mailto:tranxene50 at openvz-diff-backups.fr>> wrote:
>     >
>     > Hello!
>     >
>     > Please forgive my bad English, I live in France.
>     >
>     > Summary: how to cache - with Varnish - Open Street Map PNG
>     images without overloading OSM tiles servers?
>     >
>     > The question seems related to Varnish backends and
>     ".max_connections" parameter.
>     >
>     > A far as I know, if ".max_connections" is reached for a backend,
>     Varnish sends 503 http errors.
>     >
>     > I understand the logic but would it be possible to queue these
>     incoming requests and wait until the selected backend is really
>     available?
>     >
>     > backend a_tile? ? ? ? ? ? ? ? ? {
>     >? ?.host? ? ? ? ? ? ? ? ? ? ? ? ?= "a.tile.openstreetmap.org
>     <http://a.tile.openstreetmap.org>";
>     >? ?.port? ? ? ? ? ? ? ? ? ? ? ? ?= "80";
>     >? ?.max_connections? ? ? ? ? ? ? = 2;
>     > }
>     >
>     > If Varnish have, let's say 100 incoming requests in 1 second,
>     how can I handle this "spike" without overloading the backend?
>     >
>     > All my google searches were "dead ends" so I think the question
>     is poorly formulated.
>     >
>     > Note 1 : using [random|round_robin] directors could be a
>     temporary solution
>     > Note 2 : libvmod-dynamic is great but does not limit backend
>     simultaneous connexions
>     >
>     > Many thanks for your help!
>
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From dwetzel at atanar.com  Wed Jun 17 13:08:29 2020
From: dwetzel at atanar.com (Damien Wetzel)
Date: Wed, 17 Jun 2020 15:08:29 +0200
Subject: Caching OSM tiles - how to not overload backends?
In-Reply-To: <3be01b29-b704-3af2-57a9-2e071f1170e0@openvz-diff-backups.fr>
References: <62cc477d-e27f-1ed0-bd16-06d4c7dd907f@openvz-diff-backups.fr>
 <CABoVN9Bz-2r+Rx+zMPMb1dF3Brm3KC0jArxKvvh-wzH7aby=Fg@mail.gmail.com>
 <CAMJmMZPsxZS=nNSW70yiCkWGPsVGxKDCX9FW4PON4TccYcXMug@mail.gmail.com>
 <3be01b29-b704-3af2-57a9-2e071f1170e0@openvz-diff-backups.fr>
Message-ID: <24298.5581.636830.385652@blackcube.at.myplace>

Hi Tranx?ne50
I'm a reseller of Fastly in France a cdn based on a fork of varnish 2
maybe it could be a solution to minimize the backend traffic you receive somehow ?
i can make you test if needed
akamai has a solution they call waiting room, to regulate the traffic to the origin,
i think this is the kind of things to try to achieve ?
Best Regards,
Damien 

tranxene50 writes:
 > Hello!
 > 
 > Many thanks for your answers! :-)
 > 
 > @Dridi:
 > 
 > You are right, writing a specific VMOD would be the ideal solution but unfortunately I am not qualified for the job. ^^
 > 
 > By the way, I would like to thank all the people who are working hard to enhance and maintain Varnish.
 > 
 > This software is absolutely awesome!
 > 
 > @Xavier:
 > 
 > Before considering HAProxy, I searched if quick and dirty hacks were possible with iptables to limit simultaneous connexions and tc to shape the traffic.
 > 
 > But, after a quick reading of the documentation of HAProxy, it became clear that - as you said - it is a reliable solution.
 > 
 > So, thanks the for the hint!
 > 
 > Have a great day!
 > 
 > Le 16/06/2020 ? 00:17, Xavier Leune a ?crit?:
 > 
 >     Hello,
 >    
 >     @tranxene50 if implementing a vmod can be very challenging, using haproxy can be a great solution here. Please refer to this blog post:?
 >     https://www.haproxy.com/fr/blog/four-examples-of-haproxy-rate-limiting/?(or in french ;)?https://www.haproxy.com/fr/blog/four-examples-of-haproxy-rate-limiting/?). The very first step is about setting a
 >     maximum connections number and a queuing. Using haproxy as your backend would require low engineering and a minimum overage.
 >    
 >     Regards,
 >    
 >     Le?lun. 15 juin 2020 ??20:02, Dridi Boukelmoune <dridi at varni.sh> a ?crit?:
 > 
 >         Bonsoir,
 >        
 >         Unfortunately we don't have any sort of queuing on the backend side,
 >         so besides implementing your own backend transport from scratch in a
 >         VMOD there is currently no solution.
 >        
 >         Cordialement,
 >         Dridi
 >        
 >         On Sun, Jun 14, 2020 at 2:32 AM tranxene50
 >         <tranxene50 at openvz-diff-backups.fr> wrote:
 >         >
 >         > Hello!
 >         >
 >         > Please forgive my bad English, I live in France.
 >         >
 >         > Summary: how to cache - with Varnish - Open Street Map PNG images without overloading OSM tiles servers?
 >         >
 >         > The question seems related to Varnish backends and ".max_connections" parameter.
 >         >
 >         > A far as I know, if ".max_connections" is reached for a backend, Varnish sends 503 http errors.
 >         >
 >         > I understand the logic but would it be possible to queue these incoming requests and wait until the selected backend is really available?
 >         >
 >         > backend a_tile? ? ? ? ? ? ? ? ? {
 >         >? ?.host? ? ? ? ? ? ? ? ? ? ? ? ?= "a.tile.openstreetmap.org";
 >         >? ?.port? ? ? ? ? ? ? ? ? ? ? ? ?= "80";
 >         >? ?.max_connections? ? ? ? ? ? ? = 2;
 >         > }
 >         >
 >         > If Varnish have, let's say 100 incoming requests in 1 second, how can I handle this "spike" without overloading the backend?
 >         >
 >         > All my google searches were "dead ends" so I think the question is poorly formulated.
 >         >
 >         > Note 1 : using [random|round_robin] directors could be a temporary solution
 >         > Note 2 : libvmod-dynamic is great but does not limit backend simultaneous connexions
 >         >
 >         > Many thanks for your help!
 > 
 > 
 > ----------------------------------------------------------------------
 > _______________________________________________
 > varnish-misc mailing list
 > varnish-misc at varnish-cache.org
 > https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc

-- 



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Damien WETZEL (ATANAR TECHNOLOGIES)        ("`-/")_.-'"``-._
http://www.atanar.com                      . . `; -._    )-;-,_`)
                                          (v_,)'  _  )`-.\  ``-'
Phone:+33 9 67 35 09 05                    _.- _..-_/ / ((.'
- So much to do, so little time -       ((,.-'   ((,/            
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From tranxene50 at openvz-diff-backups.fr  Wed Jun 17 14:23:15 2020
From: tranxene50 at openvz-diff-backups.fr (tranxene50)
Date: Wed, 17 Jun 2020 16:23:15 +0200
Subject: Caching OSM tiles - how to not overload backends?
In-Reply-To: <24298.5581.636830.385652@blackcube.at.myplace>
References: <62cc477d-e27f-1ed0-bd16-06d4c7dd907f@openvz-diff-backups.fr>
 <CABoVN9Bz-2r+Rx+zMPMb1dF3Brm3KC0jArxKvvh-wzH7aby=Fg@mail.gmail.com>
 <CAMJmMZPsxZS=nNSW70yiCkWGPsVGxKDCX9FW4PON4TccYcXMug@mail.gmail.com>
 <3be01b29-b704-3af2-57a9-2e071f1170e0@openvz-diff-backups.fr>
 <24298.5581.636830.385652@blackcube.at.myplace>
Message-ID: <be935572-b096-f2d0-d4eb-877ad9804215@openvz-diff-backups.fr>

Hello Damien.

Thank you for your proposal, I appreciate!

But, as I can see/read, Fastly operates the same way as Varnish when the 
backend is overloaded (it rejects new connections):

https://docs.fastly.com/en/guides/common-503-errors#error-503-backendmax_conn-reached

The "Waiting room" could be an option (but this is not what I try to 
achieve because it throttles clients):

https://developer.fastly.com/solutions/patterns/waiting-room/

However, I prefer to stick to GPL or Open-Source projects and HAProxy 
seems perfect to regulate the traffic sent to the backend. ;-)

Regards.

Le 17/06/2020 ? 15:08, Damien Wetzel a ?crit?:
> Hi Tranx?ne50
> I'm a reseller of Fastly in France a cdn based on a fork of varnish 2
> maybe it could be a solution to minimize the backend traffic you receive somehow ?
> i can make you test if needed
> akamai has a solution they call waiting room, to regulate the traffic to the origin,
> i think this is the kind of things to try to achieve ?
> Best Regards,
> Damien
>
> tranxene50 writes:
>   > Hello!
>   >
>   > Many thanks for your answers! :-)
>   >
>   > @Dridi:
>   >
>   > You are right, writing a specific VMOD would be the ideal solution but unfortunately I am not qualified for the job. ^^
>   >
>   > By the way, I would like to thank all the people who are working hard to enhance and maintain Varnish.
>   >
>   > This software is absolutely awesome!
>   >
>   > @Xavier:
>   >
>   > Before considering HAProxy, I searched if quick and dirty hacks were possible with iptables to limit simultaneous connexions and tc to shape the traffic.
>   >
>   > But, after a quick reading of the documentation of HAProxy, it became clear that - as you said - it is a reliable solution.
>   >
>   > So, thanks the for the hint!
>   >
>   > Have a great day!
>   >
>   > Le 16/06/2020 ? 00:17, Xavier Leune a ?crit?:
>   >
>   >     Hello,
>   >
>   >     @tranxene50 if implementing a vmod can be very challenging, using haproxy can be a great solution here. Please refer to this blog post:
>   >     https://www.haproxy.com/fr/blog/four-examples-of-haproxy-rate-limiting/?(or in french ;)?https://www.haproxy.com/fr/blog/four-examples-of-haproxy-rate-limiting/?). The very first step is about setting a
>   >     maximum connections number and a queuing. Using haproxy as your backend would require low engineering and a minimum overage.
>   >
>   >     Regards,
>   >
>   >     Le?lun. 15 juin 2020 ??20:02, Dridi Boukelmoune <dridi at varni.sh> a ?crit?:
>   >
>   >         Bonsoir,
>   >
>   >         Unfortunately we don't have any sort of queuing on the backend side,
>   >         so besides implementing your own backend transport from scratch in a
>   >         VMOD there is currently no solution.
>   >
>   >         Cordialement,
>   >         Dridi
>   >
>   >         On Sun, Jun 14, 2020 at 2:32 AM tranxene50
>   >         <tranxene50 at openvz-diff-backups.fr> wrote:
>   >         >
>   >         > Hello!
>   >         >
>   >         > Please forgive my bad English, I live in France.
>   >         >
>   >         > Summary: how to cache - with Varnish - Open Street Map PNG images without overloading OSM tiles servers?
>   >         >
>   >         > The question seems related to Varnish backends and ".max_connections" parameter.
>   >         >
>   >         > A far as I know, if ".max_connections" is reached for a backend, Varnish sends 503 http errors.
>   >         >
>   >         > I understand the logic but would it be possible to queue these incoming requests and wait until the selected backend is really available?
>   >         >
>   >         > backend a_tile? ? ? ? ? ? ? ? ? {
>   >         >? ?.host? ? ? ? ? ? ? ? ? ? ? ? ?= "a.tile.openstreetmap.org";
>   >         >? ?.port? ? ? ? ? ? ? ? ? ? ? ? ?= "80";
>   >         >? ?.max_connections? ? ? ? ? ? ? = 2;
>   >         > }
>   >         >
>   >         > If Varnish have, let's say 100 incoming requests in 1 second, how can I handle this "spike" without overloading the backend?
>   >         >
>   >         > All my google searches were "dead ends" so I think the question is poorly formulated.
>   >         >
>   >         > Note 1 : using [random|round_robin] directors could be a temporary solution
>   >         > Note 2 : libvmod-dynamic is great but does not limit backend simultaneous connexions
>   >         >
>   >         > Many thanks for your help!
>   >
>   >
>   > ----------------------------------------------------------------------
>   > _______________________________________________
>   > varnish-misc mailing list
>   > varnish-misc at varnish-cache.org
>   > https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>
-- 
tranxene50
tranxene50 at openvz-diff-backups.fr


From info at massivescale.net  Mon Jun 29 09:46:14 2020
From: info at massivescale.net (Andrzej Godziuk)
Date: Mon, 29 Jun 2020 11:46:14 +0200
Subject: Caching OSM tiles - how to not overload backends?
In-Reply-To: <CAMJmMZPsxZS=nNSW70yiCkWGPsVGxKDCX9FW4PON4TccYcXMug@mail.gmail.com>
References: <62cc477d-e27f-1ed0-bd16-06d4c7dd907f@openvz-diff-backups.fr>
 <CABoVN9Bz-2r+Rx+zMPMb1dF3Brm3KC0jArxKvvh-wzH7aby=Fg@mail.gmail.com>
 <CAMJmMZPsxZS=nNSW70yiCkWGPsVGxKDCX9FW4PON4TccYcXMug@mail.gmail.com>
Message-ID: <20200629114614.395fa45c@ThinkPad>

Hi,

You may want to look into OSM-supported tile proxy software. It's not
Varnish-based but maybe one of the options would be good enough for
your use:

https://wiki.openstreetmap.org/wiki/Tile_proxy

Regards,
Andrzej