Dealing with big uploads and/or slow clients

Dealing with big uploads and/or slow clients

[Bráulio Bhavamitra]

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Hello all,

How do you deal with big uploads and/or slow clients with unicorn? The only
solution I've found was to increase timeout, because nginx can't help too,
or can?

regards,
bráulio

-- 
"Lute pela sua ideologia. Seja um com sua ideologia. Viva pela sua
ideologia. Morra por sua ideologia" P.R. Sarkar

EITA - Educação, Informação e Tecnologias para Autogestão
http://cirandas.net/brauliobo
http://eita.org.br

"Paramapurusha é meu pai e Parama Prakriti é minha mãe. O universo é meu
lar e todos nós somos cidadãos deste cosmo. Este universo é a imaginação da
Mente Macrocósmica, e todas as entidades estão sendo criadas, preservadas e
destruídas nas fases de extroversão e introversão do fluxo imaginativo
cósmico. No âmbito pessoal, quando uma pessoa imagina algo em sua mente,
naquele momento, essa pessoa é a única proprietária daquilo que ela
imagina, e ninguém mais. Quando um ser humano criado mentalmente caminha
por um milharal também imaginado, a pessoa imaginada não é a propriedade
desse milharal, pois ele pertence ao indivíduo que o está imaginando. Este
universo foi criado na imaginação de Brahma, a Entidade Suprema, por isso
a propriedade deste universo é de Brahma, e não dos microcosmos que também
foram criados pela imaginação de Brahma. Nenhuma propriedade deste mundo,
mutável ou imutável, pertence a um indivíduo em particular; tudo é o
patrimônio comum de todos."
Restante do texto em
http://cirandas.net/brauliobo/blog/a-problematica-de-hoje-em-dia

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Re: Dealing with big uploads and/or slow clients

[Eric Wong]

Bráulio Bhavamitra <braulio@eita.org.br> wrote:
> Hello all,

Hello, please stop sending HTML email, my spam filters are configured to
give HTML mail high spam scores and forces moderation, so you may not
get a response for a long time.  Non-English signature also tends to get
flagged as spam.  This is an English list.  (Fwiw, we get 10-20 spams
each day to this list which are filtered)

> How do you deal with big uploads and/or slow clients with unicorn? The only
> solution I've found was to increase timeout, because nginx can't help too,
> or can?

nginx handles slow clients extremely well.

How big are you talking about and how much RAM do you have for your OS
page cache?  Big uploads are OK if you have enough memory for caching in
Linux (or fast SSDs).  The Linux page cache is very effective if you can
process the data fairly quickly.

If your clients are very slow and uploads cannot fit in the Linux
page cache, lower your vm.dirty_* knobs (see kernel docs) to force
earlier write-out so you don't get a thundering herd of disk activity
when you run out of RAM.

I don't know about caching in other OSes.

My earliest deployments of unicorn (on a LAN) handled several terabytes
of uploads every day, so working with big uploads has always been
a priority.

The reason unicorn+nginx works well (or at all) is the attention paid to
data costs:

* Ruby processes are expensive, tens to hundreds of megabytes each
* client connections are cheap, several kilobytes at most
  (including kernel data structures)
* networks are slow, so most clients trickle

Thus we spend more time buffering in places where things are cheap, and
spend as little time holding on to big Ruby processes as possible.

.. And thus intense dislike of bloated HTML, top-posting and giant
signatures is directly tied to my software design philosophy.

Re: Dealing with big uploads and/or slow clients

[Sam Saffron]

Wouldn't you just use Rack Hijack for this, you can easily pull the
socket out of the pipeline and then deal with the upload via
eventmachine or what not.

On Fri, Jun 6, 2014 at 11:27 AM, Eric Wong <e@80x24.org> wrote:
> Bráulio Bhavamitra <braulio@eita.org.br> wrote:
>> Hello all,
>
> Hello, please stop sending HTML email, my spam filters are configured to
> give HTML mail high spam scores and forces moderation, so you may not
> get a response for a long time.  Non-English signature also tends to get
> flagged as spam.  This is an English list.  (Fwiw, we get 10-20 spams
> each day to this list which are filtered)
>
>> How do you deal with big uploads and/or slow clients with unicorn? The only
>> solution I've found was to increase timeout, because nginx can't help too,
>> or can?
>
> nginx handles slow clients extremely well.
>
> How big are you talking about and how much RAM do you have for your OS
> page cache?  Big uploads are OK if you have enough memory for caching in
> Linux (or fast SSDs).  The Linux page cache is very effective if you can
> process the data fairly quickly.
>
> If your clients are very slow and uploads cannot fit in the Linux
> page cache, lower your vm.dirty_* knobs (see kernel docs) to force
> earlier write-out so you don't get a thundering herd of disk activity
> when you run out of RAM.
>
> I don't know about caching in other OSes.
>
> My earliest deployments of unicorn (on a LAN) handled several terabytes
> of uploads every day, so working with big uploads has always been
> a priority.
>
> The reason unicorn+nginx works well (or at all) is the attention paid to
> data costs:
>
> * Ruby processes are expensive, tens to hundreds of megabytes each
> * client connections are cheap, several kilobytes at most
>   (including kernel data structures)
> * networks are slow, so most clients trickle
>
> Thus we spend more time buffering in places where things are cheap, and
> spend as little time holding on to big Ruby processes as possible.
>
> .. And thus intense dislike of bloated HTML, top-posting and giant
> signatures is directly tied to my software design philosophy.
>

Re: Dealing with big uploads and/or slow clients

[Eric Wong]

Sam Saffron <sam.saffron@gmail.com> wrote:
> Wouldn't you just use Rack Hijack for this, you can easily pull the
> socket out of the pipeline and then deal with the upload via
> eventmachine or what not.

Sure, but is that something that can Bráulio can drop in and use right
away?  I expect he's already running nginx.

If he's going to be doing that, probably easier to just another
server altogether.  yahns[1] is pretty great for that.

[1] http://yahns.yhbt.net/README  (the unicorn site has been running on
    it since November)

Re: Dealing with big uploads and/or slow clients

[Bráulio Bhavamitra]

Hello Eric,

Sorry, switched to plain text now...

So the idea is that nginx will buffer the upload request until all
data is received and then it will send it to unicorn? So unicorn only
receives the full request? Should I do some configuration to nginx for
this?

In fact, we are still using apache, but are planing to switch to nginx soon...

regards,
bráulio




On Thu, Jun 5, 2014 at 10:27 PM, Eric Wong <e@80x24.org> wrote:
> Bráulio Bhavamitra <braulio@eita.org.br> wrote:
>> Hello all,
>
> Hello, please stop sending HTML email, my spam filters are configured to
> give HTML mail high spam scores and forces moderation, so you may not
> get a response for a long time.  Non-English signature also tends to get
> flagged as spam.  This is an English list.  (Fwiw, we get 10-20 spams
> each day to this list which are filtered)
>
>> How do you deal with big uploads and/or slow clients with unicorn? The only
>> solution I've found was to increase timeout, because nginx can't help too,
>> or can?
>
> nginx handles slow clients extremely well.
>
> How big are you talking about and how much RAM do you have for your OS
> page cache?  Big uploads are OK if you have enough memory for caching in
> Linux (or fast SSDs).  The Linux page cache is very effective if you can
> process the data fairly quickly.
>
> If your clients are very slow and uploads cannot fit in the Linux
> page cache, lower your vm.dirty_* knobs (see kernel docs) to force
> earlier write-out so you don't get a thundering herd of disk activity
> when you run out of RAM.
>
> I don't know about caching in other OSes.
>
> My earliest deployments of unicorn (on a LAN) handled several terabytes
> of uploads every day, so working with big uploads has always been
> a priority.
>
> The reason unicorn+nginx works well (or at all) is the attention paid to
> data costs:
>
> * Ruby processes are expensive, tens to hundreds of megabytes each
> * client connections are cheap, several kilobytes at most
>   (including kernel data structures)
> * networks are slow, so most clients trickle
>
> Thus we spend more time buffering in places where things are cheap, and
> spend as little time holding on to big Ruby processes as possible.
>
> .. And thus intense dislike of bloated HTML, top-posting and giant
> signatures is directly tied to my software design philosophy.



-- 
"Lute pela sua ideologia. Seja um com sua ideologia. Viva pela sua
ideologia. Morra por sua ideologia" P.R. Sarkar

EITA - Educação, Informação e Tecnologias para Autogestão
http://cirandas.net/brauliobo
http://eita.org.br

"Paramapurusha é meu pai e Parama Prakriti é minha mãe. O universo é
meu lar e todos nós somos cidadãos deste cosmo. Este universo é a
imaginação da Mente Macrocósmica, e todas as entidades estão sendo
criadas, preservadas e destruídas nas fases de extroversão e
introversão do fluxo imaginativo cósmico. No âmbito pessoal, quando
uma pessoa imagina algo em sua mente, naquele momento, essa pessoa é a
única proprietária daquilo que ela imagina, e ninguém mais. Quando um
ser humano criado mentalmente caminha por um milharal também
imaginado, a pessoa imaginada não é a propriedade desse milharal, pois
ele pertence ao indivíduo que o está imaginando. Este universo foi
criado na imaginação de Brahma, a Entidade Suprema, por isso a
propriedade deste universo é de Brahma, e não dos microcosmos que
também foram criados pela imaginação de Brahma. Nenhuma propriedade
deste mundo, mutável ou imutável, pertence a um indivíduo em
particular; tudo é o patrimônio comum de todos."
Restante do texto em
http://cirandas.net/brauliobo/blog/a-problematica-de-hoje-em-dia

Re: Dealing with big uploads and/or slow clients

[Michael Fischer]

On Fri, Jun 6, 2014 at 6:31 AM, Bráulio Bhavamitra <braulio@eita.org.br> wrote:

> So the idea is that nginx will buffer the upload request until all
> data is received and then it will send it to unicorn? So unicorn only
> receives the full request? Should I do some configuration to nginx for
> this?

Yes; there are a few tunables worth looking at.  The "Buffers" section
here offers some useful discussion:

https://www.digitalocean.com/community/articles/how-to-optimize-nginx-configuration

Best regards,

--Michael