Re: [gentoo-user] Re: Steam downloading extremely

[Danny YUE]

Hi Kai,

Oops, fixed?

I just updated my system and tried to randomly download another game
and it looks fine...

Weird.

Anyway, thanks for you guys.
May the good code be with you.

Danny


On 2017-03-19 19:11, Kai Krakow  wrote:
> Am Thu, 16 Mar 2017 14:04:14 +0800
> schrieb Danny YUE :
>
>> Hi Kai,
>> 
>> Thanks for your help :-)
>> 
>> Code here:
>> /usr/share/info $ cat /proc/sys/net/ipv4/tcp_fastopen
>> 1
>> /usr/share/info $ cat /proc/sys/net/core/default_qdisc
>> pfifo_fast
>> /usr/share/info $ cat /proc/sys/net/ipv4/tcp_congestion_control
>> cubic
>> 
>> dnsmasq may help because...if my understanding is correct, Steam Linux
>> client has a bug that it tries to query the DNS too often during
>> downloading, then its request got throttled. Please see
>> https://wiki.gentoo.org/wiki/Steam/Client_troubleshooting
>> Section "Slow download speeds".
>
> This has been fixed with the March 9th 2017 Update. It's in the current
> stable client.
>
>> For disk, I don't think it fits my case because for a downloading
>> speed of 100KB/s, disk write should not be a bottleneck.
>
> Well, it still can be if there's a lot of data backlogged and the
> writeback cache of the kernel is saturated.
>
>> I suspect it is related to Linux client because Steam Windows client
>> on my machine downloads at the normal speed...
>
> This makes sense... However, here the linux client is downloading at 48
> mbytes/s which is pretty much the maximum of my 400 mbit link.
>
> So, if it is still slow for you, there seem to be other issues.
>
>> Well, I am not that familiar with network tuning things...so I will
>> definitely check the methods you mentioned.
>
> Feel free to ask.
>
>> On 2017-03-15 21:07, Kai Krakow  wrote:
>> > Am Wed, 15 Mar 2017 21:53:44 +0100
>> > schrieb Kai Krakow :
>> >  
>> >> Am Wed, 15 Mar 2017 21:24:10 +0800
>> >> schrieb Danny YUE :
>> >>  
>>  [...]  
>> >>
>> >> Here, it's downloading with peak bandwidths of 48 mbytes/s but
>> >> usually it's around 38 mbytes/s. However, I sometimes see
>> >> slowdowns, too. I guess that games are downloaded file by file,
>> >> and when a lot of small files are left in the queue, it just
>> >> cannot get good bandwidth.
>> >>
>> >> But I only see such slowdowns mostly short before the last few
>> >> megabytes of a game.
>> >>
>> >> Could you check if your downloaded games consist of many smallish
>> >> files? Then that could be the explanation.
>> >>
>> >> You could try activating fq_codel and tcp fastopen:
>> >>
>> >> In /proc/sys/net/ipv4/tcp_fastopen it should say 1.
>> >> In /proc/sys/net/core/default_qdisc it should say fq_codel.
>> >>
>> >> Also, you may want to try out bbr congestion control:
>> >>
>> >> In /proc/sys/net/ipv4/tcp_congestion_control it should say bbr.
>> >>
>> >> By recompiling the kernel, you can reconfigure the defaults for
>> >> this (and enable support). Some of these need modern kernels.
>> >>
>> >> Additionally, many small tcp request need a good portion of your
>> >> upload bandwidth and are very dependent on good round trip times.
>> >> Traditional DSL lines with ping times of 50-60ms can really slow
>> >> down requests of small files a lot due to three-way tcp
>> >> handshaking, that is, you could request only one smallish file per
>> >> 100-120ms. This can totally destroy the usable bandwidth. Maybe
>> >> watch a running ping while the downloads are running. If the ping
>> >> times increase while the download slows down, your bottleneck is
>> >> the upload.
>> >>
>> >> But also keep in mind that traditional spinning disks may not keep
>> >> up with the bandwidth if confronted with many small files. If
>> >> you're using SSD all should be fine. I'm running on bcache with
>> >> writeback caching which gives a really good performance boost by
>> >> adding a small SSD to one or more big HDDs.  
>> >
>> > BTW: I don't see how dnsmasq could help you here... It can do
>> > nothing about bandwidth. It only acts as a DNS cache which helps
>> > keeping latency of the DNS resolver down. But this doesn't matter
>> > here because during download, steam won't do many DNS requests.
>> >
>> > As already stated, part of the problem may be the upload, and/or bad
>> > queue handling within your broadband router. You can work around it
>> > with a traffic shaper and throttling upload below what's physically
>> > possible with your internet line, thus keeping the queue in front
>> > of the broadband router. That way, a traffic shaper could handle it
>> > and work around bad queue handling.
>> >
>> > To resolve the issue it is important to sophistically test the
>> > suggestions one step at a time, starting with the easy ones, and do
>> > your measurements.  
>> 
>> 

[gentoo-user] Re: Steam downloading extremely

[Kai Krakow]

Am Thu, 16 Mar 2017 14:04:14 +0800
schrieb Danny YUE :

> Hi Kai,
> 
> Thanks for your help :-)
> 
> Code here:
> /usr/share/info $ cat /proc/sys/net/ipv4/tcp_fastopen
> 1
> /usr/share/info $ cat /proc/sys/net/core/default_qdisc
> pfifo_fast
> /usr/share/info $ cat /proc/sys/net/ipv4/tcp_congestion_control
> cubic
> 
> dnsmasq may help because...if my understanding is correct, Steam Linux
> client has a bug that it tries to query the DNS too often during
> downloading, then its request got throttled. Please see
> https://wiki.gentoo.org/wiki/Steam/Client_troubleshooting
> Section "Slow download speeds".

This has been fixed with the March 9th 2017 Update. It's in the current
stable client.

> For disk, I don't think it fits my case because for a downloading
> speed of 100KB/s, disk write should not be a bottleneck.

Well, it still can be if there's a lot of data backlogged and the
writeback cache of the kernel is saturated.

> I suspect it is related to Linux client because Steam Windows client
> on my machine downloads at the normal speed...

This makes sense... However, here the linux client is downloading at 48
mbytes/s which is pretty much the maximum of my 400 mbit link.

So, if it is still slow for you, there seem to be other issues.

> Well, I am not that familiar with network tuning things...so I will
> definitely check the methods you mentioned.

Feel free to ask.

> On 2017-03-15 21:07, Kai Krakow  wrote:
> > Am Wed, 15 Mar 2017 21:53:44 +0100
> > schrieb Kai Krakow :
> >  
> >> Am Wed, 15 Mar 2017 21:24:10 +0800
> >> schrieb Danny YUE :
> >>  
>  [...]  
> >>
> >> Here, it's downloading with peak bandwidths of 48 mbytes/s but
> >> usually it's around 38 mbytes/s. However, I sometimes see
> >> slowdowns, too. I guess that games are downloaded file by file,
> >> and when a lot of small files are left in the queue, it just
> >> cannot get good bandwidth.
> >>
> >> But I only see such slowdowns mostly short before the last few
> >> megabytes of a game.
> >>
> >> Could you check if your downloaded games consist of many smallish
> >> files? Then that could be the explanation.
> >>
> >> You could try activating fq_codel and tcp fastopen:
> >>
> >> In /proc/sys/net/ipv4/tcp_fastopen it should say 1.
> >> In /proc/sys/net/core/default_qdisc it should say fq_codel.
> >>
> >> Also, you may want to try out bbr congestion control:
> >>
> >> In /proc/sys/net/ipv4/tcp_congestion_control it should say bbr.
> >>
> >> By recompiling the kernel, you can reconfigure the defaults for
> >> this (and enable support). Some of these need modern kernels.
> >>
> >> Additionally, many small tcp request need a good portion of your
> >> upload bandwidth and are very dependent on good round trip times.
> >> Traditional DSL lines with ping times of 50-60ms can really slow
> >> down requests of small files a lot due to three-way tcp
> >> handshaking, that is, you could request only one smallish file per
> >> 100-120ms. This can totally destroy the usable bandwidth. Maybe
> >> watch a running ping while the downloads are running. If the ping
> >> times increase while the download slows down, your bottleneck is
> >> the upload.
> >>
> >> But also keep in mind that traditional spinning disks may not keep
> >> up with the bandwidth if confronted with many small files. If
> >> you're using SSD all should be fine. I'm running on bcache with
> >> writeback caching which gives a really good performance boost by
> >> adding a small SSD to one or more big HDDs.  
> >
> > BTW: I don't see how dnsmasq could help you here... It can do
> > nothing about bandwidth. It only acts as a DNS cache which helps
> > keeping latency of the DNS resolver down. But this doesn't matter
> > here because during download, steam won't do many DNS requests.
> >
> > As already stated, part of the problem may be the upload, and/or bad
> > queue handling within your broadband router. You can work around it
> > with a traffic shaper and throttling upload below what's physically
> > possible with your internet line, thus keeping the queue in front
> > of the broadband router. That way, a traffic shaper could handle it
> > and work around bad queue handling.
> >
> > To resolve the issue it is important to sophistically test the
> > suggestions one step at a time, starting with the easy ones, and do
> > your measurements.  
> 
> 



-- 
Regards,
Kai

Replies to list-only preferred.

Re: [gentoo-user] Re: Steam downloading extremely

[Danny YUE]

Hi Kai,

Thanks for your help :-)

Code here:
/usr/share/info $ cat /proc/sys/net/ipv4/tcp_fastopen
1
/usr/share/info $ cat /proc/sys/net/core/default_qdisc
pfifo_fast
/usr/share/info $ cat /proc/sys/net/ipv4/tcp_congestion_control
cubic

dnsmasq may help because...if my understanding is correct, Steam Linux
client has a bug that it tries to query the DNS too often during
downloading, then its request got throttled. Please see
https://wiki.gentoo.org/wiki/Steam/Client_troubleshooting
Section "Slow download speeds".

For disk, I don't think it fits my case because for a downloading speed
of 100KB/s, disk write should not be a bottleneck.

I suspect it is related to Linux client because Steam Windows client on
my machine downloads at the normal speed...

Well, I am not that familiar with network tuning things...so I will
definitely check the methods you mentioned.

Thanks,
Danny


On 2017-03-15 21:07, Kai Krakow  wrote:
> Am Wed, 15 Mar 2017 21:53:44 +0100
> schrieb Kai Krakow :
>
>> Am Wed, 15 Mar 2017 21:24:10 +0800
>> schrieb Danny YUE :
>>
>> > Hi guys,
>> >
>> > I just got Steam installed and running successfully on my machine,
>> > and tried to get CS:GO running smoothly, which made me really
>> > happy :-D
>> >
>> > However when Steam is downloading games, the speed is extremely
>> > slow, down to several KB/s, even some bytes/s.
>> > I have already installed dnsmasq and it *was* good during
>> > downloading CS:GO (~4MB/s), but became slow again with Civilization
>> > V.
>> >
>> > I googled a lot but all point to installing dnsmasq, which I don't
>> > think is really helpful since I already have done that...
>> >
>> > Also I'm sure downloading region is correct.
>> >
>> > Anybody experienced the same issue with dnsmasq installed?
>> > Any clue is welcome and thanks in advance.
>>
>> Here, it's downloading with peak bandwidths of 48 mbytes/s but usually
>> it's around 38 mbytes/s. However, I sometimes see slowdowns, too. I
>> guess that games are downloaded file by file, and when a lot of small
>> files are left in the queue, it just cannot get good bandwidth.
>>
>> But I only see such slowdowns mostly short before the last few
>> megabytes of a game.
>>
>> Could you check if your downloaded games consist of many smallish
>> files? Then that could be the explanation.
>>
>> You could try activating fq_codel and tcp fastopen:
>>
>> In /proc/sys/net/ipv4/tcp_fastopen it should say 1.
>> In /proc/sys/net/core/default_qdisc it should say fq_codel.
>>
>> Also, you may want to try out bbr congestion control:
>>
>> In /proc/sys/net/ipv4/tcp_congestion_control it should say bbr.
>>
>> By recompiling the kernel, you can reconfigure the defaults for this
>> (and enable support). Some of these need modern kernels.
>>
>> Additionally, many small tcp request need a good portion of your
>> upload bandwidth and are very dependent on good round trip times.
>> Traditional DSL lines with ping times of 50-60ms can really slow down
>> requests of small files a lot due to three-way tcp handshaking, that
>> is, you could request only one smallish file per 100-120ms. This can
>> totally destroy the usable bandwidth. Maybe watch a running ping
>> while the downloads are running. If the ping times increase while the
>> download slows down, your bottleneck is the upload.
>>
>> But also keep in mind that traditional spinning disks may not keep up
>> with the bandwidth if confronted with many small files. If you're
>> using SSD all should be fine. I'm running on bcache with writeback
>> caching which gives a really good performance boost by adding a small
>> SSD to one or more big HDDs.
>
> BTW: I don't see how dnsmasq could help you here... It can do nothing
> about bandwidth. It only acts as a DNS cache which helps keeping
> latency of the DNS resolver down. But this doesn't matter here because
> during download, steam won't do many DNS requests.
>
> As already stated, part of the problem may be the upload, and/or bad
> queue handling within your broadband router. You can work around it
> with a traffic shaper and throttling upload below what's physically
> possible with your internet line, thus keeping the queue in front of the
> broadband router. That way, a traffic shaper could handle it and work
> around bad queue handling.
>
> To resolve the issue it is important to sophistically test the
> suggestions one step at a time, starting with the easy ones, and do
> your measurements.

[gentoo-user] Re: Steam downloading extremely

[Kai Krakow]

Am Wed, 15 Mar 2017 21:53:44 +0100
schrieb Kai Krakow :

> Am Wed, 15 Mar 2017 21:24:10 +0800
> schrieb Danny YUE :
> 
> > Hi guys,
> > 
> > I just got Steam installed and running successfully on my machine,
> > and tried to get CS:GO running smoothly, which made me really
> > happy :-D
> > 
> > However when Steam is downloading games, the speed is extremely
> > slow, down to several KB/s, even some bytes/s.
> > I have already installed dnsmasq and it *was* good during
> > downloading CS:GO (~4MB/s), but became slow again with Civilization
> > V.
> > 
> > I googled a lot but all point to installing dnsmasq, which I don't
> > think is really helpful since I already have done that...
> > 
> > Also I'm sure downloading region is correct.
> > 
> > Anybody experienced the same issue with dnsmasq installed?
> > Any clue is welcome and thanks in advance.  
> 
> Here, it's downloading with peak bandwidths of 48 mbytes/s but usually
> it's around 38 mbytes/s. However, I sometimes see slowdowns, too. I
> guess that games are downloaded file by file, and when a lot of small
> files are left in the queue, it just cannot get good bandwidth.
> 
> But I only see such slowdowns mostly short before the last few
> megabytes of a game.
> 
> Could you check if your downloaded games consist of many smallish
> files? Then that could be the explanation.
> 
> You could try activating fq_codel and tcp fastopen:
> 
> In /proc/sys/net/ipv4/tcp_fastopen it should say 1.
> In /proc/sys/net/core/default_qdisc it should say fq_codel.
> 
> Also, you may want to try out bbr congestion control:
> 
> In /proc/sys/net/ipv4/tcp_congestion_control it should say bbr.
> 
> By recompiling the kernel, you can reconfigure the defaults for this
> (and enable support). Some of these need modern kernels.
> 
> Additionally, many small tcp request need a good portion of your
> upload bandwidth and are very dependent on good round trip times.
> Traditional DSL lines with ping times of 50-60ms can really slow down
> requests of small files a lot due to three-way tcp handshaking, that
> is, you could request only one smallish file per 100-120ms. This can
> totally destroy the usable bandwidth. Maybe watch a running ping
> while the downloads are running. If the ping times increase while the
> download slows down, your bottleneck is the upload.
> 
> But also keep in mind that traditional spinning disks may not keep up
> with the bandwidth if confronted with many small files. If you're
> using SSD all should be fine. I'm running on bcache with writeback
> caching which gives a really good performance boost by adding a small
> SSD to one or more big HDDs.

BTW: I don't see how dnsmasq could help you here... It can do nothing
about bandwidth. It only acts as a DNS cache which helps keeping
latency of the DNS resolver down. But this doesn't matter here because
during download, steam won't do many DNS requests.

As already stated, part of the problem may be the upload, and/or bad
queue handling within your broadband router. You can work around it
with a traffic shaper and throttling upload below what's physically
possible with your internet line, thus keeping the queue in front of the
broadband router. That way, a traffic shaper could handle it and work
around bad queue handling.

To resolve the issue it is important to sophistically test the
suggestions one step at a time, starting with the easy ones, and do
your measurements.

-- 
Regards,
Kai

Replies to list-only preferred.

[gentoo-user] Re: Steam downloading extremely

[Kai Krakow]

Am Wed, 15 Mar 2017 21:24:10 +0800
schrieb Danny YUE :

> Hi guys,
> 
> I just got Steam installed and running successfully on my machine,
> and tried to get CS:GO running smoothly, which made me really
> happy :-D
> 
> However when Steam is downloading games, the speed is extremely slow,
> down to several KB/s, even some bytes/s.
> I have already installed dnsmasq and it *was* good during downloading
> CS:GO (~4MB/s), but became slow again with Civilization V.
> 
> I googled a lot but all point to installing dnsmasq, which I don't
> think is really helpful since I already have done that...
> 
> Also I'm sure downloading region is correct.
> 
> Anybody experienced the same issue with dnsmasq installed?
> Any clue is welcome and thanks in advance.

Here, it's downloading with peak bandwidths of 48 mbytes/s but usually
it's around 38 mbytes/s. However, I sometimes see slowdowns, too. I
guess that games are downloaded file by file, and when a lot of small
files are left in the queue, it just cannot get good bandwidth.

But I only see such slowdowns mostly short before the last few
megabytes of a game.

Could you check if your downloaded games consist of many smallish
files? Then that could be the explanation.

You could try activating fq_codel and tcp fastopen:

In /proc/sys/net/ipv4/tcp_fastopen it should say 1.
In /proc/sys/net/core/default_qdisc it should say fq_codel.

Also, you may want to try out bbr congestion control:

In /proc/sys/net/ipv4/tcp_congestion_control it should say bbr.

By recompiling the kernel, you can reconfigure the defaults for this
(and enable support). Some of these need modern kernels.

Additionally, many small tcp request need a good portion of your upload
bandwidth and are very dependent on good round trip times. Traditional
DSL lines with ping times of 50-60ms can really slow down requests of
small files a lot due to three-way tcp handshaking, that is, you could
request only one smallish file per 100-120ms. This can totally destroy
the usable bandwidth. Maybe watch a running ping while the downloads
are running. If the ping times increase while the download slows down,
your bottleneck is the upload.

But also keep in mind that traditional spinning disks may not keep up
with the bandwidth if confronted with many small files. If you're using
SSD all should be fine. I'm running on bcache with writeback caching
which gives a really good performance boost by adding a small SSD to
one or more big HDDs.

-- 
Regards,
Kai

Replies to list-only preferred.