Freewheel

Reply
Active Member
Posts: 10
Registered: ‎01-24-2005
Message 11 of 15 (173 Views)

Re: caching gone bad?

05-18-2007 04:27 PM in reply to: nienberg
I've confirmed that FreeWheel honors the expire header if I set it explicitly, but your 4.5 day timeout when there is no expire header does not seem to work. After about 10 days of waiting I finally changed the name of my dwf directory to force FreeWheel to start fresh.

In my case I had initially requested images of dwf files that did not exist, so when freewheel requested them from my server, it was probably given a page not found error. After that, it would always return a blank viewer for that dwf, even after I put the dwf file in the right place so it would be found.
*Scott Sheppard - Autodesk
Message 12 of 15 (173 Views)

Re: caching gone bad?

05-18-2007 05:14 PM in reply to: nienberg
Thank you for this feedback. We will look into it.

wrote in message news:5591303@discussion.autodesk.com...
I've confirmed that FreeWheel honors the expire header if I set it
explicitly, but your 4.5 day timeout when there is no expire header does not
seem to work. After about 10 days of waiting I finally changed the name of
my dwf directory to force FreeWheel to start fresh.

In my case I had initially requested images of dwf files that did not exist,
so when freewheel requested them from my server, it was probably given a
page not found error. After that, it would always return a blank viewer for
that dwf, even after I put the dwf file in the right place so it would be
found.
Member
Posts: 5
Registered: ‎07-21-2007
Message 13 of 15 (173 Views)

Re: caching gone bad?

07-23-2007 04:15 PM in reply to: nienberg
Regarding caching, I may not want to change the cache settings for my entire site just to accommodate Freewheel's caching policy.

I also may be using freewheel on my site against URL's containing DWF's from a third remote site where I have no control over their servers caching.

Can you add an optional parameter to your server which allows me to use a: ,,,,&forcecachereload=1 sort of option?

Commenting on previous discussion, checking changes in the file based on file sizes is obviously a bad idea, however you could certainly checksum them. In fact, (I'd bet but I'm guessing) that the DWF format itself has a checksum in the file? If so, perhaps you could use that to first use the checksum to validate your cached version and upload the rest of the file if the checksum is different.
(of course now you're trading off two roundtrips, but given the size of the files, it's probably worth it.)

-Steve.
*Scott Sheppard - Autodesk
Message 14 of 15 (173 Views)

Re: caching gone bad?

07-24-2007 12:51 AM in reply to: nienberg
In our opinion cache headers are specifically designed to tell us when to
check.

wrote in message news:5666925@discussion.autodesk.com...
Regarding caching, I may not want to change the cache settings for my entire
site just to accommodate Freewheel's caching policy.

I also may be using freewheel on my site against URL's containing DWF's from
a third remote site where I have no control over their servers caching.

Can you add an optional parameter to your server which allows me to use a:
,,,,&forcecachereload=1 sort of option?

Commenting on previous discussion, checking changes in the file based on
file sizes is obviously a bad idea, however you could certainly checksum
them. In fact, (I'd bet but I'm guessing) that the DWF format itself has a
checksum in the file? If so, perhaps you could use that to first use the
checksum to validate your cached version and upload the rest of the file if
the checksum is different.
(of course now you're trading off two roundtrips, but given the size of the
files, it's probably worth it.)

-Steve.
*Ben Cochran \(Autodesk\)
Message 15 of 15 (173 Views)

Re: caching gone bad?

07-24-2007 09:30 AM in reply to: nienberg
Cache headers can be set for the whole site, a whole directory or just a
single file.



Also, the cache headers tell the Freewheel server when to check. If the time
has elapsed, the Freewheel server will check to see if the DWF is newer and
will only download the DWF if it is newer. Your suggestion is checking every
time is a good one. The problem is how often should the Freewheel server
check? The check can take more than a second depending several variables.
Should the server check after each frame? That would not work. Even a check
every hour, would be much for some servers. It is best to set the cache
headers on your DWF files and tell the Freewheel servers how often to check.



Ben



wrote in message news:5666925@discussion.autodesk.com...
Regarding caching, I may not want to change the cache settings for my entire
site just to accommodate Freewheel's caching policy.

I also may be using freewheel on my site against URL's containing DWF's from
a third remote site where I have no control over their servers caching.

Can you add an optional parameter to your server which allows me to use a:
,,,,&forcecachereload=1 sort of option?

Commenting on previous discussion, checking changes in the file based on
file sizes is obviously a bad idea, however you could certainly checksum
them. In fact, (I'd bet but I'm guessing) that the DWF format itself has a
checksum in the file? If so, perhaps you could use that to first use the
checksum to validate your cached version and upload the rest of the file if
the checksum is different.
(of course now you're trading off two roundtrips, but given the size of the
files, it's probably worth it.)

-Steve.

You are not logged in.

Log into access your profile, ask and answer questions, share ideas and more. Haven't signed up yet? Register

Announcements
Welcome to the new Autodesk Community!
If this is your first visit, click here to get started and make the most of the Community. Let us know what you think of the new experience in the Community Feedback Forum.

Need installation help?

Start with some of our most frequented solutions to get help installing your software.

Ask the Community