[ZWeb] Re: zope.org - serious caching issues
I just discussed this with Jim and he concurs that it's a problem within Zope, he gets the same results (old data) tunneling directly to the app servers. I believe he's planning on investigating further, but he's unavailable at the moment. --Dave Systems Administrator Zope Corp. 540-361-1722 [EMAIL PROTECTED] ___ Zope-web maillist - Zope-web@zope.org http://mail.zope.org/mailman/listinfo/zope-web
Re: [ZWeb] Re: zope.org - serious caching issues
Well, trying to figure out what's changed...that would be the first thing I'd check; just verify that the rules are indeed hitting the requests. How long has this problem been evident? When did the changes take place? I presume awhile ago? Most of the changes would've been some time ago, on the order of nine months to a year at least. I did make some changes, recently, a few weeks ago, but mostly just management stuff. I did find one refresh pattern that was commented out on the parents but not on the children, so I put that back in. Can someone who understand the parameters of the issue better than I do check and see if it's still being problematic? It's possible the change I just made fixed it, though I'd be somewhat surprised, since there's talk of things being cached for, like, several weeks and I don't see anything in the cache tier that would allow such a thing. --Dave Systems Administrator Zope Corp. 540-361-1722 [EMAIL PROTECTED] ___ Zope-web maillist - Zope-web@zope.org http://mail.zope.org/mailman/listinfo/zope-web
Re: [ZWeb] Re: zope.org - serious caching issues
On Mon, 2007-05-21 at 16:42 -0400, David Lawson wrote: > > It has, but mostly only in layout and some streamlining of the > configuration. The basic rules you established are still in place, > since we assumed you had good reasons for them. I haven't been > following this discussion terribly closely, but I'll take a closer > look at things this evening. Well, trying to figure out what's changed...that would be the first thing I'd check; just verify that the rules are indeed hitting the requests. How long has this problem been evident? When did the changes take place? I presume awhile ago? Andrew ___ Zope-web maillist - Zope-web@zope.org http://mail.zope.org/mailman/listinfo/zope-web
Re: [ZWeb] Re: zope.org - serious caching issues
It looks to me like the cache tier has been changed; IIRC zope.org was not in the cache tier I setup for Managed Hostingand didn't have (at least) 4 cache servers in it's request flow. Yes. The cache tier has changed significantly, but the basic configuration is still the same. It's been a long time, but IIRC we got rid of all caching for zope.org where a cache header wasn't explicitly being set. This is still the case. There's a refresh-pattern in place for the entirety of *.zope.org that should allow nothing without some sub-set of the proper cache control headers to be set. A valid subset would be at least a Last-Modified and either an Expires or a Cache-Control: max-age. Neither of these appear to be set, so that refresh pattern should be in effect. Was the cache servers changed around? IIRC the zope.org tier only had 2 measly cachesand if they changed, I bet the rules where not changed along with the cache servers. It has, but mostly only in layout and some streamlining of the configuration. The basic rules you established are still in place, since we assumed you had good reasons for them. I haven't been following this discussion terribly closely, but I'll take a closer look at things this evening. --Dave Systems Administrator Zope Corp. 540-361-1722 [EMAIL PROTECTED] ___ Zope-web maillist - Zope-web@zope.org http://mail.zope.org/mailman/listinfo/zope-web
Re: [ZWeb] Re: zope.org - serious caching issues
On Mon, 2007-05-21 at 10:09 -0400, Jim Fulton wrote: > I'm adding zope-web to the CC list. > I wish you hadn't done that yet. If we keep changing things. it will > be hard to figure this out. > > It would be helpful to show the results of, say wget -S, as in: > > [EMAIL PROTECTED]:~/tmp$ wget -S http://www.zope.org/news.rss > --09:58:05-- http://www.zope.org/news.rss > => `news.rss' > Resolving www.zope.org... 63.240.213.171 > Connecting to www.zope.org|63.240.213.171|:80... connected. > HTTP request sent, awaiting response... >HTTP/1.0 200 OK >Server: Zope/(unreleased version, python 2.2.3, linux2) ZServer/1.1b1 >Date: Mon, 21 May 2007 13:57:28 GMT >Content-Length: 4011 >Content-Type: text/xml >Age: 4 >X-Cache: HIT from parent-ng2.zmh.zope.net >X-Cache: MISS from cache2.zmh.zope.net >Connection: close > Length: 4,011 (3.9K) [text/xml] > > 100%[>] 4,011 --.--K/s > > 09:58:05 (365.80 KB/s) - `news.rss' saved [4011/4011] > > [EMAIL PROTECTED]:~/tmp$ wget --user jim --password xx -S http:// > www.zope.org/news.rss > --10:00:45-- http://www.zope.org/news.rss > => `news.rss.1' > Resolving www.zope.org... 63.240.213.171 > Connecting to www.zope.org|63.240.213.171|:80... connected. > HTTP request sent, awaiting response... >HTTP/1.0 200 OK >Server: Zope/(unreleased version, python 2.2.3, linux2) ZServer/1.1b1 >Date: Mon, 21 May 2007 13:45:20 GMT >Content-Length: 4011 >Content-Type: text/xml >X-Cache: HIT from parent-ng2.zmh.zope.net >Age: 892 >X-Cache: HIT from cache4.zmh.zope.net >Connection: close > Length: 4,011 (3.9K) [text/xml] > > 100%[>] 4,011 --.--K/s > > 10:00:45 (1.85 MB/s) - `news.rss.1' saved [4011/4011] It looks to me like the cache tier has been changed; IIRC zope.org was not in the cache tier I setup for Managed Hostingand didn't have (at least) 4 cache servers in it's request flow. > > Note that the second request is authenticated (except with a > different password :) That won't make any difference...they both resulted in a cache hit. The first time, you hit a front side cache server that didn't have it cached: cache2, the second time, you hit a cache server that did have it cached: cache4. > > ... > > >> The objects do not display any caching policy in ZMI, but the cache > >> manager still shows the enties in different variations. What cache manager? > > Possibly because it doesn't know about the change. > > > > It looks like in issue in Zope. > > How so? If you look at the wget output above, there don't seem to be > any cache headers set. So, data would not be cached unless there is > an overriding policy in squid. If the cache tier was changed and relying on the (old) default settings, then it's going to cache for a certain period of time. > > > If you see both te child and the parent MISS, > > then what you're getting is coming from the app server. Yup. > > I'm getting a hit from the parent. Also note that both hits have me > results for which the most recent entry is from March 29. If I bust > the cache with a query string, the most recent entry is for May 15. > > > > That would also > > explain differences based on roles. There is nothing in squid that > > distinguishes if a user is authenticated, anonymous or manager. I don't follow this, what explains the difference; there should be no difference based on roles. > > I *think* Andrew Sawyers did something to arrange that non-anonymous > users get non-cached results. This doesn't seem to be working any > more. This is bad. I'm hoping that however got this working properly > at some point can tell us what they did. :) It's been a long time, but IIRC we got rid of all caching for zope.org where a cache header wasn't explicitly being set. > > Jim Was the cache servers changed around? IIRC the zope.org tier only had 2 measly cachesand if they changed, I bet the rules where not changed along with the cache servers. Andrew ___ Zope-web maillist - Zope-web@zope.org http://mail.zope.org/mailman/listinfo/zope-web
[ZWeb] Re: zope.org - serious caching issues
I'm adding zope-web to the CC list. On May 20, 2007, at 1:42 PM, Mark W. Alexander wrote: On Saturday 19 May 2007, Michael Haubenwallner wrote: Michael, I'm sorry I dropped the ball on this. I said I'd look into it and got distracted. Mark W. Alexander schrieb: On Friday 18 May 2007, you wrote: Hi, i experience problems with the news listing and rss feed on zope.org : http://www.zope.org (right column) http://www.zope.org/News/ (News listing) http://www.zope.org/news.rss (news rss feed) http://www.zope.org/products.rss (products rss feed) The pages / feeds are different for authenticated and anonymous users. Refreshing (even forced) does not produce a correct page, same results with non-browser based retrieval (wget, urllib). Adding a querystring to the URL returns updated data - but that for logged in Users only. What do you mean by "different" for authenticated and anonymous users? It looks the same to me both ways. Pages will cache for 15 minutes _per_cache_ so when you are making many changes you'll see differences depending on which cache you hit. Any query string will bust the cache once, but only once, as the url?string will produce a new, unique cache url. You can use wget's -S option to see the X-Cache headers for the caches the request is using as well as the Age (in seconds) of the cached object. That information may help your analysis. Mark Checking again this morning i see no difference - there is still (2 month) old data showing on frontpage and in the rss feeds ... I've looked into the scripts that compute the data /zopeorg/news.rss /zopeorg/products.rss /zopeorg/latestContentBySubject In ZMI all three objects are cached by an 'Accelerated HTTP Cache Manager'. I subsequently removed the 'Five minutes' cache from the objects and checked that stats page for several minutes (see below) I wish you hadn't done that yet. If we keep changing things. it will be hard to figure this out. It would be helpful to show the results of, say wget -S, as in: [EMAIL PROTECTED]:~/tmp$ wget -S http://www.zope.org/news.rss --09:58:05-- http://www.zope.org/news.rss => `news.rss' Resolving www.zope.org... 63.240.213.171 Connecting to www.zope.org|63.240.213.171|:80... connected. HTTP request sent, awaiting response... HTTP/1.0 200 OK Server: Zope/(unreleased version, python 2.2.3, linux2) ZServer/1.1b1 Date: Mon, 21 May 2007 13:57:28 GMT Content-Length: 4011 Content-Type: text/xml Age: 4 X-Cache: HIT from parent-ng2.zmh.zope.net X-Cache: MISS from cache2.zmh.zope.net Connection: close Length: 4,011 (3.9K) [text/xml] 100%[>] 4,011 --.--K/s 09:58:05 (365.80 KB/s) - `news.rss' saved [4011/4011] [EMAIL PROTECTED]:~/tmp$ wget --user jim --password xx -S http:// www.zope.org/news.rss --10:00:45-- http://www.zope.org/news.rss => `news.rss.1' Resolving www.zope.org... 63.240.213.171 Connecting to www.zope.org|63.240.213.171|:80... connected. HTTP request sent, awaiting response... HTTP/1.0 200 OK Server: Zope/(unreleased version, python 2.2.3, linux2) ZServer/1.1b1 Date: Mon, 21 May 2007 13:45:20 GMT Content-Length: 4011 Content-Type: text/xml X-Cache: HIT from parent-ng2.zmh.zope.net Age: 892 X-Cache: HIT from cache4.zmh.zope.net Connection: close Length: 4,011 (3.9K) [text/xml] 100%[>] 4,011 --.--K/s 10:00:45 (1.85 MB/s) - `news.rss.1' saved [4011/4011] Note that the second request is authenticated (except with a different password :) ... The objects do not display any caching policy in ZMI, but the cache manager still shows the enties in different variations. Possibly because it doesn't know about the change. It looks like in issue in Zope. How so? If you look at the wget output above, there don't seem to be any cache headers set. So, data would not be cached unless there is an overriding policy in squid. If you see both te child and the parent MISS, then what you're getting is coming from the app server. I'm getting a hit from the parent. Also note that both hits have me results for which the most recent entry is from March 29. If I bust the cache with a query string, the most recent entry is for May 15. That would also explain differences based on roles. There is nothing in squid that distinguishes if a user is authenticated, anonymous or manager. I *think* Andrew Sawyers did something to arrange that non-anonymous users get non-cached results. This doesn't seem to be working any more. This is bad. I'm hoping that however got this working properly at some point can tell us what they did. :) Jim -- Jim Fulton mailto:[EMAIL PROTECTED]Python Powered! CTO (540) 361-1714 http://www.python.org Zope Corporationhttp://www.zope.com http://www.zope.org
