Files on server still there?

[=VALOR=]

Hi everyone.

Heres something weird: I just deletes some files from my server, and when i access them through the browser, they are still there!?!? (I cleared my cache, delted all temp files, everything).

Any ideas / explanations?

Thanks.

=VALOR=

[abzoid]

Possibly due to server caching, try checking again after some time has passed.

[=VALOR=]

Server caching?!? Is that possible? How do i disable that?

[reverendflash]

you can't....

Revhttp://www.aulman.com/rev.gif

[abzoid]

If it's a plain HTML or Flash page then you can't easily disable it. Server caching is a function used by some web servers to help reduce processor load. By caching frequently accessed pages it saves time repeatedly fetching them from the source location on the hard drive. When you're editing a page, uploading, viewing, editing some more, repeat... You sometimes trip the cache frequency setting.

I do know of an ASP command that tells the server not to cache the page. I assume there is an equivalent one in PHP, but there isn't one for HTML or Flash. since they are client side not server side.

[=VALOR=]

Aaarghhhhhhhhhhh this sucks!!!!!!!!

So what do you guys do when testing flash movies about 100 times a day online? (Like preloaders and such that work best online)


What if if instead of HTML I use PHP or ASP and put my flash movie in there? Will it stop caching then even if the flash movie imports external text files / pics?

Btw thanks for all your help so far :)

=VALOR=

[reverendflash]

nope... servers will automatically cache your images/flash movies. It is there to reduce load on the servers, and Flash files are one of the biggest loads...

PHP and ASP won't help in this instance...

I test locally, then when complete, I upload to the server.

abzoid and I have had problems with this in the past...

Revhttp://www.aulman.com/rev.gif

[=VALOR=]

Hi again.

Ive been looking into this "!§"$/(? cache issue. I contacted the host company, and they mentioned that it is not a server cache issue, but an ISP cache one. I then found this article online:

----------------------------------------------------------

Gory Detail...
For me a webmaster of a website "YOUR ISP" web cache can reduce the number of pages my server has to send thereby lowering my hosting cost BUT for YOU it may be a bad deal!
Your local ISP cache is one of my pet peeves. It's a case of fleecing the public by ripping them off with the "appearance" of a fast loading Internet connection when in fact it isn't. Cache (often called a proxy, proxy cache, webcache) is a tool that more and more Internet provides (the guy you pay for access) are switching to to lower the amount of data that goes through them (through-put) between you and the website you are visiting. If your ISP can prevent your surfing request from coming in their front door and going out their back door (known as thru-put) to a website they save money by intercepting your request and giving you "something" locally off a computer at your iSP. The more times they do this (serve locally) the more money they save.
My objection is a marginal ISP starts using cache instead of updating their equipment and typically won't tell you. You may actually "think" they have gotten better but they're handing you back the same pages you (or someone else) have already looked at. There are lots of configuration options to set up ISP cache and if they were used sensibly ISP cache would be a benefit but the the bottom line is the saving a few bucks. Unless you're smart you won't even know if your provider has a caching proxy or when they switch to one (I didn't). Typically the switch is not explained outlining the negative aspect of looking at old stale web pages...

I see it every time I change something at the website... You visit my website (or so you think) and see all kinds of errors, broken images, missing links and other crap. What's happening is you're being fooled..., you're not visiting my website but a mirror copy of all or part of it that is now in YOUR ISP CACHE. This page will quickly pop on your screen and you're happy BUT... the page is a month old and many thing have changed that you are not seeing. Links no longer go to the same place and you don't see the latest updates! If you're knowledgeable you "may" be able to FORCE your ISP to refresh the cache but not always. I've seen people visiting from a cached page that was over a month old!

Good and smart cache would take a quick look at my website for the page you are requesting and update if necessary and if it had already been updated simply give you the cached version. If ISP cache worked this way things would be better but typically it doesn't... because a little more through-put can be saved by NOT checking each page and image (every time) but just updating at some fixed time period that is the option of your ISP techs and... it's to their benefit NOT to refresh very often, especially if you're not complaining.

So... Joe public #1 visits and causes the cache to grab all the pages he looks at (or crawls or spiders the site) and stores the pages and (perhaps) the images at the ISP so later in the day when Joe Public #2 (you) visit you get a quick downloaded page because the page is served to you locally from your ISP. That isn't so bad but what if it's two or four weeks later and it's still the same old cache... Some websites are dynamic in that they are always changing pages and pictures! You're screwed.

This is right up there with the Power Companies that have a rolling black-out because they don't have or won't spend the bucks to keep things updated and YOU SUFFER. Unlike power companies you do have other ISP's you can switch to BUT ask about their caching policy. Often you're lied to because the person you're talking to is the F.L.A. (first level ape) that knows less about things than you do. You have to get to the second or third level before they know and UNDERSTAND what you are asking. "Do we have cash?"... "No, cache!"
Things to ask your ISP:
Do you have web cache?
How often is the cache refreshed?
How long will pages stay in cache until they are dropped?
Does your cache automatically spider the entire website?
Are images cached or just pages?
When I visit a web page does the cache actually check to see if there is a newer page available and retrieve it?
Why are you cacheing?
Some people consider ISP cacheing a cheap money making trick, have you told your customers you intend to (or do) use web cacheing?
Note: ISP Web cache can be useful IF it's used smartly and check pages for updates as it's used. Unfortunately there is no incentive to do this.


There are some legal issues concerning ISP cacheing. I'm not really worried about this but absolutely no ISP has ever asked me permission to cache my webpages. You ask why should they ask? Imagine a person making an exact copy of my website and offering it to people..., that is not allowed and is considered illegal copyright infringement. Another problem is someone using a cached page may see broken links and missing pictures all of which reflect negatively on the website and drive away potential customers. Another issue is if something is offered such as a short duration special (perhaps for free) the visitor may never see the offer when viewing a cached page.

Most of you have heard of "browser cache" which is much the same thing BUT is good because you control it, can shut it off, force a reload or have it refreshed. ISP cache you're totally at the mercy of your ISP who is trying to put off upgrading equipment and reducing "slow speed" complaints.

Sorry, but I don't have an answer for you other than to inform you. MY PERSONAL ISP caches and I hate it. If I make a change to my website I don't see it without forcing a cache refresh.

So..., just remember AOL, @HOME, Earthlink, almost all large networks, and now even small ISP users that proxy typically means cache and cache means you are looking at history, old stuff, or at least not the very latest... Learn about your ISP cache or caching proxy and find out the limitations and "if" you can refresh it.

You folks with ISDN, DSL, and other high speed connections still have ISP cache to contend with BUT it may be even more of a rip-off for you because you have (and are paying for) a high speed connection! Do you really care that a page loads in 2 seconds instead of 3 seconds? Of course not BUT you do care if what you're looking at is old and outdated or broken pages!
End of soapbox... -Indy

---------------------------------

If this is correct (and it sounds to me like it is, because i havnt changed hosts, and i didnt have this problem in Brussels, but im having it in Spain.) then the problem is much worse. Its easier to change hosts then ISP.....

:skull:

=VALOR=

:skull:

[eyezberg]

It is all true, I'm on cable here in France, and I had the problem just yesterday.
PHPforFlash was updated, it's a new swf with page numbers for the threads and posts, so you only see 25 each page. I cleared my cache 4 times, checked the site with Netscape, which I never use, and I was still on the old swf, so not able to see any new post (nothing after N° 25). The following morning, it was ok, which in a sense is good coz that means they cache "only" 24h... but it's VERY annoying, specially with the $$ you pay for broadband!

[=VALOR=]

I think I have found a way to beat the "Proxy Cache" as it is officially known.

More details soon.

=V=

[Marz]

Just handle the cache locally in the header field on the HTTP Protocol Language Settings..

<META NAME="Pragma" CONTENT="No-Cache">

Try that out.. Should go between the <head></head> lines... These demand that the page no longer be stored or cached locally.

Now.. Serverly... I'm not sure if it will help or not... It may or may not help.. Just one of those interesting questions.

[abzoid]

The Meta tag command will have no effect on server caching.

[Marz]

No.. But sometimes your main ie caching unit doesn't save correctly in the tmp files directory causing ie to not delete it when told. THis will make sure that NONE of your pages get cached locally.. Notice the word locally.. There was no need to reiterate the fact that I had stated that.

[reverendflash]

but that is what he is asking.

your response could have been read as an option, when it wasn't...

that is all...

Revhttp://aulman.com/rev.gif

[abzoid]

Originally posted by playamarz
.. There was no need to reiterate the fact that I had stated that.

OK, if you say so.

There was no need for your post in the first place, as it was totally unrelated to the server cache/proxy cache issue.

[Marz]

This is indeed, not a server caching problem anymore.. Therefore my response was valid.. And onto my explanations.

There is absolutly NO REASON AT ALL for a server to cache a file locally if it is being deleted from the server.. NO REASON! Why would a server allow someone to delete a file only to rename it and save it back in the directory as the same file? It wouldn't... That's just plain stupid. And if a server exists out there that does something like this then I wanna know, so I can brutally beat them down with a handful of Cheese Puffs.

Server caching does exist, but everytime you update, upload or change something in it's directory through FTP or anytype of webserver management program, it automatically updates the server caching registry.. If it didn't, absolutly no sites would be able to update at all!

Your flash problem occurs to many people, but there is a really simple way to make sure that your flash pages never get cached and stored... By implementing a small amount of code in it to make it a unique filename everytime.

Using a little bit of php you can tell the server to upload the Flash File as if it were to have a query string line in it... The query string line automatically uploads the newest page no matter what.. What's the use of having a dynamic server if you can't update things through query strings or post commands?

Append this to the end of the .swf like such...

mymovie.swf?uId=768974938679

Now.. How can you get unique numbers all of the time? Just use the date features.. Every second in a long string of date numbers would make a new number.. Think about it.. Right now for instance would be..

1641321062003
Or
16:41:32 10/6/2003

Or now..

1642051062003
Or
16:42:05 10/6/2003

Now.. it needs to be in military time, but that isn't too hard to figure out either...

Now.. To ISP Caching.. This can be a very big problem but the Unique Id Query String Line should work out just fine for you..

Now, if I'm correct.. I'm the only one that pointed out the fact that it might have been the meta tags.. Because there is that chance.. Ruling that out completely is very, very prudish for a programmer to even think of. I was merely helping and that fact that you responded in such a way is rather unveiling... Please do not respond in such ways to people that are trying to help. Every little piece of code can help out.. Even if it doesn't seem to help out his problem to you.

[reverendflash]

Marlin:

calm down, stop acting like someone stole your favorite chew toy.

abzoid did nothing to you, so don't make this a personal attack.

If you are looking to get famous for your help
Now, if I'm correct.. I'm the only one that pointed out the fact that it might have been the meta tags.., then go somewhere else, as you know we don't go that way here.

also, if the server admin wishes the items to be updated every day @1:00 AM, then so be it. It happens sometimes that the server caches stuff.

and before you start flipping someone sh1t, you might wish to do some research as to thier personality/history...

Revhttp://aulman.com/rev.gif

[=VALOR=]

:m:

Ok here goes: This is a little messy, but its giving me pretty good results so far, and the page always updates correctly on the server when I hit refresh:

Put the following code at the beginning, AND AT THE END of your html code:

BEGINNING: (In the Meta tags)
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="expires" content="0">


END: (Just before the /html)
<HEAD><META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE"></HEAD>
</HTML>


The double header seems to actually work!!

When pressing REFRESH, hold down the CTRL key....


Give it a try people and let me know how it went.

Oh, dont forget to clear your local cache, of course.

:q:

[Marz]

There are times when it is best to just shut up and walk away.. After reviewing this.. I think I will.. And from now on.. I will continue to shut up in this section..

As your comment, about me "thinking" that I want to try and get famous off the posts here, rather hurt. If I honestly thought that way do you think I would take the time, out of my work hours, just to help the poor guy possibly?

Oh well.. Here I thoguht I was actually helping.. Take care..

No harm intended by this post.. And I'd rather not be replied unless it to be in secrecy.. it seems our friend has fgured it out and this discussion should be dropped.. Have a good evening.

[reverendflash]

Originally posted by =VALOR=
:m:

Ok here goes: This is a little messy, but its giving me pretty good results so far, and the page always updates correctly on the server when I hit refresh:

Put the following code at the beginning, AND AT THE END of your html code:

BEGINNING: (In the Meta tags)
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<META HTTP-EQUIV="expires" content="0">


END: (Just before the /html)
<HEAD><META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE"></HEAD>
</HTML>


The double header seems to actually work!!

When pressing REFRESH, hold down the CTRL key....


Give it a try people and let me know how it went.

Oh, dont forget to clear your local cache, of course.

:q:

Or, if it is your local machine you are concerned about, simply switch to a Mozilla based browser, and set your cache to 0...

and I can't help but feel the double header thing is an anomaly... I don't see how it can work that way... it should just ignore the 2nd header...

but I've been wrong many times before... I think...

Revhttp://aulman.com/rev.gif