cache confusion

[Christian Riechers]

Running FF on Linux. With about:cache I do see the following:
Memory cache device
Disk cache device
Offline cache device

Running FF on Vista. With about:cache I do see the following:
Disk cache device
Offline cache device

This is with both, FF12, and FF13 beta. Is there no memory cache for the
Windows version?
Thanks.

--
Christian

[Poutnik]

In article posted Sun, 20 May 2012 11:35:28 +0200 to
mozilla.support.firefox,
Christian Riechers posted this..

I do have memory device on my Vista 64 and FF 12.0.
You may check your about:config setting for cache a/o memory

browser.cache.memory.enable;true (default )
browser.cache.memory.max_entry_size;5120

--
Poutnik

[Christian Riechers]

That's already set in both profiles.
I'm certain when creating a new profile this is fixed. However, that's
what I'm trying to avoid.
Any other ideas?

--
Christian

[Christian Riechers]

Just to add this.
Two different FF12 profiles running on WinXP, and no memory cache
either. So I really wonder if memory cache is used on Windows at all.
If so, any ideas on how to restore the memory cache?

--
Christian

[David]

I am using the Nightly (15.0a1) on Windows 7 x86_64 and I have 'Memory
cache' listed.
Actually it says:

Information about the Cache Service

Memory cache device

Disk Cache device

Offline cache device

--

David

[Christian Riechers]

It seems there is some automatic mechanism involved. Upon browser
start-up no memory cache device exists. However, it is created
dynamically at some point when using the browser.
Can anyone provide some more details on this?

--
Christian

[Keith Nuttle]

Is Firefox set to clear the cache on exit? It so

[Desiree]

"Christian Riechers" <chrie...@netscape.net.invalid> wrote in message
news:mPOdnffbTc_9tiTS...@mozilla.org...

Do you have broadband? If so, then why is your cache service not disabled?
You don't need cache of any kind unless on dialup. It was useful then. It is
merely annoying and not needed on broadband. I have had the cache service
disabled since 2001 when I got broadband. I disabled cache on all browsers
years ago.

[Poutnik]

In article posted Sun, 20 May 2012 23:46:34 -1000 to
mozilla.support.firefox,
Desiree posted this..

> Do you have broadband? If so, then why is your cache service not
disabled?
> You don't need cache of any kind unless on dialup. It was useful then. It is
> merely annoying and not needed on broadband.

That is not fully true.

The speed of page fetching is determined by bottleneck
of the whole line
server - internet - last mile connection.

For broadband is last mile never the bottleneck.
Some pages are slow to fetch even on my ISP 100/100 Mbit/s connection.

--
Poutnik

[David Boles]

I always thought that:

You 'view' a page so the browser has to download it. Once. And stores
it in the cache. Some days later you 'view' that same page. The
browser compares the stored page with the page at the URL. The page is
different? Download it again since it is different. The page is
identical? Use the stored version and don't spend the time and
bandwidth to download the same page again.

Did that change?

[Poutnik]

In article posted Mon, 21 May 2012 08:50:57 -0400 to
mozilla.support.firefox,
David Boles posted this..

I suppose I is always the same.

But there is problem with some modern web technologies
when the pages are not static, or are dynamicacally generated.

It is managed by http headers, related to cache management.

--
Poutnik

[Christian Riechers]

No. Why would this matter for the memory cache?

--
Christian

[Christian Riechers]

On 05/21/2012 11:46 AM, Desiree wrote:
> "Christian Riechers" <chrie...@netscape.net.invalid> wrote in message
> news:mPOdnffbTc_9tiTS...@mozilla.org...
>> On 05/20/2012 02:44 PM, Christian Riechers wrote:
>>> On 5/20/2012 11:35 AM, Christian Riechers wrote:
>>>> Running FF on Linux. With about:cache I do see the following:
>>>> Memory cache device
>>>> Disk cache device
>>>> Offline cache device
>>>>
>>>> Running FF on Vista. With about:cache I do see the following:
>>>> Disk cache device
>>>> Offline cache device
>>>>
>>>> This is with both, FF12, and FF13 beta. Is there no memory cache for the
>>>> Windows version?
>>>> Thanks.
>>>
>>> Just to add this.
>>> Two different FF12 profiles running on WinXP, and no memory cache
>>> either. So I really wonder if memory cache is used on Windows at all.
>>> If so, any ideas on how to restore the memory cache?
>>
>> It seems there is some automatic mechanism involved. Upon browser
>> start-up no memory cache device exists. However, it is created
>> dynamically at some point when using the browser.
>> Can anyone provide some more details on this?
>

> Do you have broadband? If so, then why is your cache service not disabled?
> You don't need cache of any kind unless on dialup. It was useful then. It is
> merely annoying and not needed on broadband. I have had the cache service
> disabled since 2001 when I got broadband. I disabled cache on all browsers
> years ago.

I'm certain that fetching an item from memory is ways faster than
fetching it from the server again, regardless of the Internet connection
speed.
The remaining question is how the underlying mechanism works, which
creates the memory cache device.

--
Christian

[Ron Hunter]

I agree. No real benefit to a disk cache with broadband. The only
advantage is very slow connection, and/or extended use of highly graphic
websites that don't change their graphics often.

[Ron Hunter]

Most ISPs maintain what is called an 'inline' cache which caches the
page you just requested, if it is not already in the cache (or has
expired), so that if you request it again, the content is supplied from
their server. If you see a lot of delay getting pages you just viewed a
few seconds, or minutes, ago, then it is likely your ISP isn't able to
supply its users the data without going back to the source. It either
is overloaded, or undercached. (if that's a word).

[Keith Nuttle]

Because as I understand the cache is only designated when the cache is
kept. If the cache is it cleared on exit, the cache is held as a
temporary file that is erased when Firefox closes.

[PhillipJones]

I have 3 MB DSL and some download reasonably fast then again some
especially when downloading software acts like the are still using 56K
modems. I almost believe some sites still are. I've tried different DNS
servers one from my ISP, the one from Google, and one from OpenDNS.
Usually works better with open DNS but stometimes I have to switch
around to get kick started.

--
Phillip M. Jones, C.E.T. "If it's Fixed, Don't Break it"
http://www.phillipmjones.net mailto:pjo...@kimbanet.com

[Poutnik]

In article posted Mon, 21 May 2012 17:07:00 -0500 to
mozilla.support.firefox,
Ron Hunter posted this..

>
> On 5/21/2012 7:33 AM, Poutnik wrote:
> > In article posted Sun, 20 May 2012 23:46:34 -1000 to
> > mozilla.support.firefox,
> > Desiree posted this..
> >
> >> Do you have broadband? If so, then why is your cache service not
> > disabled?
> >> You don't need cache of any kind unless on dialup. It was useful then. It is
> >> merely annoying and not needed on broadband.
> >
> > That is not fully true.
> >
> > The speed of page fetching is determined by bottleneck
> > of the whole line
> > server - internet - last mile connection.
> >
> > For broadband is last mile never the bottleneck.
> > Some pages are slow to fetch even on my ISP 100/100 Mbit/s connection.
> >
> Most ISPs maintain what is called an 'inline' cache which caches the
> page you just requested, if it is not already in the cache (or has
> expired), so that if you request it again, the content is supplied from

I am aware of that, but ISP expiration is supposed shorter,
and will not cache the page only you visited few days ago.

> their server. If you see a lot of delay getting pages you just viewed a
> few seconds, or minutes, ago, then it is likely your ISP isn't able to
> supply its users the data without going back to the source. It either
> is overloaded, or undercached. (if that's a word).

A page can request by http header noit to be cached,
a/o a page cannot be cached due the its nature,
being generated all the time.



--
Poutnik

[Poutnik]

In article posted Mon, 21 May 2012 20:50:55 -0400 to
mozilla.support.firefox,
PhillipJones posted this..

> modems. I almost believe some sites still are. I've tried different DNS
> servers one from my ISP, the one from Google, and one from OpenDNS.
> Usually works better with open DNS but stometimes I have to switch
> around to get kick started.

According to DNSbench tool by GRC
those public DNS are always slow for me.

Even if OpenDNS has interesting features.

--
Poutnik

[Ron Hunter]

On 5/21/2012 7:50 PM, PhillipJones wrote:
> Poutnik wrote:
>> In article posted Sun, 20 May 2012 23:46:34 -1000 to
>> mozilla.support.firefox,
>> Desiree posted this..
>>
>>> Do you have broadband? If so, then why is your cache service not
>> disabled?
>>> You don't need cache of any kind unless on dialup. It was useful
>>> then. It is
>>> merely annoying and not needed on broadband.
>>
>> That is not fully true.
>>
>> The speed of page fetching is determined by bottleneck
>> of the whole line
>> server - internet - last mile connection.
>>
>> For broadband is last mile never the bottleneck.
>> Some pages are slow to fetch even on my ISP 100/100 Mbit/s connection.
>>
> I have 3 MB DSL and some download reasonably fast then again some
> especially when downloading software acts like the are still using 56K
> modems. I almost believe some sites still are. I've tried different DNS
> servers one from my ISP, the one from Google, and one from OpenDNS.
> Usually works better with open DNS but stometimes I have to switch
> around to get kick started.
>

Some sites are supported on slower lines, and others are 'throttled' by
the site owner to keep their rates down.

[Desiree]

"Ron Hunter" <rphu...@charter.net> wrote in message
news:qcSdnaiSb6rHxCbS...@mozilla.org...

Plus 3mbps down is barely broadband these days. I am on 10/1 and not many
have broadband as low as mine these days. I'm hoping I can afford 20/2 when
it gets here soon (15/1 is being eliminated). Most these days have 30/5 (or
at least 20/2 when it gets here) and some 50/5 or higher.

Also, everyone is on DOCSIS 3 now even if you have 10/1 and a DOCSIS 2 modem
and bottleneck at the last mile is pretty much a thing of past on DOCSIS 3.
Even DOCSIS 1.1 modems benefit from a DOCSIS 3 CMTS. DSL is not much better
than dialup so those on it will probably have different experiences from
those on DOCSIS 3 cable internet connections.

[Christian Riechers]

On 05/22/2012 01:55 AM, Keith Nuttle wrote:
> On 5/21/2012 2:11 PM, Christian Riechers wrote:
>> On 05/21/2012 03:36 AM, Keith Nuttle wrote:
>>>> On 5/20/2012 8:44 AM, Christian Riechers wrote:
>>>>> On 5/20/2012 11:35 AM, Christian Riechers wrote:
>>>>>> Running FF on Linux. With about:cache I do see the following:
>>>>>> Memory cache device
>>>>>> Disk cache device
>>>>>> Offline cache device
>>>>>>
>>>>>> Running FF on Vista. With about:cache I do see the following:
>>>>>> Disk cache device
>>>>>> Offline cache device
>>>>>>
>>>>>> This is with both, FF12, and FF13 beta. Is there no memory cache for
>>>>>> the
>>>>>> Windows version?
>>>>>> Thanks.
>>>>>
>>>>> Just to add this.
>>>>> Two different FF12 profiles running on WinXP, and no memory cache
>>>>> either. So I really wonder if memory cache is used on Windows at all.
>>>>> If so, any ideas on how to restore the memory cache?
>>>>>

>>> Is Firefox set to clear the cache on exit? It so
>>
>> No. Why would this matter for the memory cache?
>>
> Because as I understand the cache is only designated when the cache is
> kept. If the cache is it cleared on exit, the cache is held as a
> temporary file that is erased when Firefox closes.

The way I understand it is that no disk cache is created/used if one has
'clear cache on exit' enabled.
This is primarily for security reasons. In case of a browser crash the
disk cache would remain, and potentially expose sensitive information
which would normally have been cleared upon exit.
Wrt memory cache, it is destroyed upon exit regardless. So again, I
don't see how the 'clear cache on exit' setting is related to memory cache.

--
Christian

[Christian Riechers]

On 05/22/2012 02:50 AM, PhillipJones wrote:
> Poutnik wrote:
>> In article posted Sun, 20 May 2012 23:46:34 -1000 to
>> mozilla.support.firefox,
>> Desiree posted this..
>>
>>> Do you have broadband? If so, then why is your cache service not
>> disabled?
>>> You don't need cache of any kind unless on dialup. It was useful
>>> then. It is
>>> merely annoying and not needed on broadband.
>>
>> That is not fully true.
>>
>> The speed of page fetching is determined by bottleneck
>> of the whole line
>> server - internet - last mile connection.
>>
>> For broadband is last mile never the bottleneck.
>> Some pages are slow to fetch even on my ISP 100/100 Mbit/s connection.
>>
> I have 3 MB DSL and some download reasonably fast then again some
> especially when downloading software acts like the are still using 56K
> modems. I almost believe some sites still are. I've tried different DNS
> servers one from my ISP, the one from Google, and one from OpenDNS.
> Usually works better with open DNS but stometimes I have to switch
> around to get kick started.

How would a slow DNS server affect the download speed of a large file?

--
Christian

[Christian Riechers]

Just in case it isn't obvious, the topic of this thread is about memory
cache.

--
Christian

[Christian Riechers]

On 05/22/2012 11:16 AM, Ron Hunter wrote:
>> Poutnik wrote:
>>> In article posted Sun, 20 May 2012 23:46:34 -1000 to
>>> mozilla.support.firefox,
>>> Desiree posted this..
>>>
>>>> Do you have broadband? If so, then why is your cache service not
>>> disabled?
>>>> You don't need cache of any kind unless on dialup. It was useful
>>>> then. It is
>>>> merely annoying and not needed on broadband.
>>>
>>> That is not fully true.
>>>
>>> The speed of page fetching is determined by bottleneck
>>> of the whole line
>>> server - internet - last mile connection.
>>>
>>> For broadband is last mile never the bottleneck.
>>> Some pages are slow to fetch even on my ISP 100/100 Mbit/s connection.
>>>

> Some sites are supported on slower lines, and others are 'throttled' by
> the site owner to keep their rates down.

Where a disk cache would help them to keep their rates down.

--
Christian

[Ron Hunter]

Don't write off slow connections yet. It has only been a year that US
internet users passed the 50% stage of broadband installation. That
means there are still almost half the users who are at speeds under
56kb/s. And some 'broadband' installations barely merit the
description. My sister in law moved into an apartment yesterday and her
'broadband' was installed today. I set up her computer, and managed
only 756kb down and 770kb up. Pretty pathetic!
My speeds are pretty good for this area with up to 30mbps up and 3.3
mpbs up. Also, many rural locations only have access at all through
Hughes satellite service, which is not fast, but IS expensive.

[»Q«]

On Sun, 20 May 2012 11:35:28 +0200
Christian Riechers <chrie...@netscape.net.invalid> wrote:

> Running FF on Linux. With about:cache I do see the following:
> Memory cache device
> Disk cache device
> Offline cache device
>
> Running FF on Vista. With about:cache I do see the following:
> Disk cache device
> Offline cache device
>
> This is with both, FF12, and FF13 beta. Is there no memory cache for
> the Windows version?

a) I don't know, but

b) What does about:cache?device=memory say? I doubt it will help solve
the mystery, but I'm curious.

[Christian Riechers]

Actually part of the mystery has been resolved. The memory cache device
isn't necessarily created right at browser start-up, it seems it is
being created dynamically at some point.
I'd still be interested in some more detailed information about this
mechanism, but no one came up with something so far.
about:cache?device=memory returns an empty page right after browser
start-up.

--
Christian

[David]

You do realize that you are talking to a group of ordinary users on a
help/support list and not to Mozilla developers? Perhaps Google is your
friend here?
--

David

[bjlockie]

I think the memory cache stores your input so if you accidentally leave a page, you can go back and what you typed will be there.

[Robert Miles]

How can the browser compare the stored page with the page at the URL
unless it downloads the page at the URL before this comparison?

[WLS]

Any help?

http://palizine.plynt.com/issues/2008Jul/cache-control-attributes/

--
openSUSE 12.1 | KDE 4.8.4
Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120619 Thunderbird/14.0

[Ron Hunter]

That leaves out the fact that most ISPs have what are called 'inline
caches'. That way, the data is cached if ANYONE from that ISP has
requested a page since it changed at the originating site, and they can
just push the cached version to the user without needing to even contact
the original server other than to check the date on the page. Saves
lots of data flowing across the backbone.
And, yes, the last mile CAN be a bottleneck if the service provider
doesn't have enough bandwidth to service all its customers.

[Robert Miles]

On 7/15/2012 7:50 AM, WLS wrote:

Yes. Thank you.