OK. I confirmed that Roller 2.3 does not send Last-Modified headers for
certain (possibly all) struts actions, particularly main.do which serves the
front page in 2.3, but it does send the Last-Modified header for blog pages.
Wherever Roller 2.3 does send the header, I see exactly the same issue with
IE set to the "Automatic" setting, so the issue is not a new 3.0-specific
one as I had first thought.
What *is* new and initially caught my attention is that in Roller 3.0 we now
see this staleness behavior in IE on the front page, because the front page
is actually associated to a blog page, and gets the Last-Modified header.
Upshot: I think we should continue the current 3.0 behavior, but I won't be
surprised if we later get requests to make it configurable, at least for the
front page to avoid the issue with default IE settings. We should wait for
that though.
--a.
----- Original Message -----
From: "Anil Gangolli" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, September 03, 2006 11:28 PM
Subject: Re: problems with 3.0 on IE
Yep. I agree. I'm not sure if there is anything to do here. I'll be
trying to understand this further; I'll try to compare what's happening
with 2.3 and 3.0 more carefully before making a recommendation.
--a.
----- Original Message -----
From: "Allen Gilliland" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, September 03, 2006 10:47 PM
Subject: Re: problems with 3.0 on IE
eeks. I don't think changing our app to not send Last-Modified headers
is the right approach. The Last-Modified header is an http standard and
if IE is doing something wrong with it then that's their fault, not ours.
I think that everything that you listed in your bullets below is correct
behavior for the cache control. A browser can only send an
If-Modified-Since header if it has gotten a Last-Modified header, and it
sounds like when the headers are present (like in firefox) then
everything works properly.
It's not really our fault if IE is being overly aggressive about its
caching.
-- Allen
Anil Gangolli wrote:
Scratch the fourth bullet. We are sending a Last-Modified header in
2.3, so I still don't know what's different between 3.0 and 2.3
----- Original Message ----- From: "Anil Gangolli" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, September 03, 2006 7:37 PM
Subject: Re: problems with 3.0 on IE
Here's what I found:
- Apparently a recent MS update had reset my caching preferences to
allow IE to decide whent to check for modified pages "automatically",
(the meaning of which is described here:
http://support.microsoft.com/?kbid=263070). In the cases I diagnosed,
the browser was indeed, as Allen thought, not even sending a request.
- If I change IE's cache control policy to check on "Every visit to
the page", I see requests from IE carrying If-Modified-Since headers
and what looks like correct cache behavior stepping through
PageServlet.
- It appears that "Automatically" is the default setting that IE ships
with.
- If we don't send "Last-Modified" headers and I keep the defaul
"Automatically" setting, IE appears to send requests every time, but
with no If-Modified-Since header at all.
- It appears that in trunk and 2.3 we were not sending the
"Last-Modified" header. That code is commented out, without an
explanation. (Anyone recall why? Did it have anything to do with IE?)
I think this might explain the difference in behavior I'm seeing with
2.3.
I think we might want to add a configuration parameter to control
whether or not to send the Last-Modified header, or spend more time
figuring out a way to work properly with IE's default setting.
--a.
----- Original Message ----- From: "Allen Gilliland"
<[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, September 02, 2006 11:07 PM
Subject: Re: problems with 3.0 on IE
Anil Gangolli wrote:
----- Original Message ----- From: "Allen Gilliland"
<[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, September 01, 2006 9:18 AM
Subject: Re: problems with 3.0 on IE
Anil Gangolli wrote:
I'm seeing several odd problems with 3.0 on IE 6 on my local build.
I seem to be getting stale versions of pages unless I load
bypassing the cache.
I don't see how the caching could be having a different affect from
one browser to the next. What do you mean "bypassing the cache"?
I mean forced reload which tells the browser to (a) ignore its local
cache (b) don't send an If-Modified-Since header.
gotcha.
It's possible it's just bad browser caching. I know that firefox
can be really tricky with browser caching if you aren't careful,
especially with feeds. I know for a fact that there are times in
firefox when it won't even sent a request for a page to check 304,
it will just automatically use the browser cache, although i haven't
figured out the exact conditions for that yet.
I haven't diagnosed it yet, but I suspect it is that we are not
responding properly to some IfModified-qualified requests.
That's possible, I never use IE so I can't say that everything is
tested as well in IE. I know that one thing that can cause problems
with if-modified headers is date conversions, if for some reason IE is
doing something even just a few milliseconds different from the
application that can cause the 304 checking to be wrong.
-- Allen
Note: There are no proxies or intermediate servers between the
browser and my dev Tomcat running on the same host.
Has anyone else seen this with IE on current 3.0 builds? I don't
want to hold anything up if it is a personal setup issue.
-- Allen
Is anyone else testing with IE?
I don't see the same problem with Firefox.
This is specific to 3.0. I'm not seeing this on 2.3.
I've just started looking into it, but hesitant to call this a
release candidate without it.
--a.
