You are here: Foswiki>Tasks Web>Item14126 (18 Feb 2017, GeorgeClark)Edit Attach

Item14126: Random topics or webs get access restricted

Priority: Urgent
Current State: No Action Required
Released In: n/a
Target Release: n/a
Applies To: Engine
Reported By: Ehj52N
Waiting For: Main.Ehj52N
Last Change By: GeorgeClark

-- Ehj52N - 03 Aug 2016


I have a foswiki installation running with v2.1.2 with the following plugins:

Here is a list of the plugins currently installed and enabled in the wrench configuration on this Foswiki site:


I get random topics and webs with access restrictions. Hence, sometimes a single topic is not accessible for not logged in users and another time a whole web get's restricted.


HELP This workaround is not really good, because the topics and webs, that get blocked, are somehow chosen randomly.

  1. Access the blocked topic or web as admin.
  2. Open the according web's ~WebPreferences topic.
  3. Edit the ~WebPreferences; not really edit something but just open in raw edit mode and save it.
  4. Wait some time and the access set-up is fixed again.


Do you need additional information about the set-up or server environment?

-- Ehj52N - 03 Aug 2016

Are you using mod_perl or fcgi? For something to come/go like this, it sounds like there could be some in-memory reuse issues. You might try running with fcgi if on mod_perl. We use fcgi on and have not seen any inconsistencies like this. Rather than editing/saving, you might try reloading the server to see if that clears the issue. If that works, let us know.

-- GeorgeClark - 03 Aug 2016

Hi Clark,
I am using mod_fcgid. I tried reloading the server various times and it did not work. Today, I updated all web's WebPreferences following UpgradingFromOlderTWikiReleases#Convert_empty_DENY_ACLs_to_ALLOW_42_wildcards and updated them by hand. I hope that this solves my issue. I think that the problem here is that it must be clearer stated in the migration guide that the WebPreferences of each web have to be updated, too.
By the way, sorry for the late reply. It seems that the WebNotify creation script is not working well, as I cannot find my username on this topic 6 days after creating this issue.
Kind regards!

-- Ehj52N - 09 Aug 2016

The problem happened again and the workflow to open and directly save the according WebPreferences failed because the MySQL took more than 5 minutes to process this save. I think that the according cache update took so long. Hence, I disabled caching and the save works fast and without any error.

So, maybe the cache is the source of the problem!? What do you think?

-- Ehj52N - 06 Sep 2016

Yes we've seen some performance issues with the page cache, though mysql seems quite a bit better than sqllite. We've got some fixes planned for 2.1.3, which will reduce the size of the dependencies table. Also, if you have a lot of webs, the WebLeftBarWebsList will result in every topic becoming dependent upon every web preferences. Yet another reason to disable the poorly performing dynamic webs list.

-- GeorgeClark - 31 Oct 2016

Hi George, thank you very much for your update. Is there an option to replace the dynamic webs list by something more static? I do not want to update all WebLeftBar by hand, when adding a new web. Looking forward to version 2.1.3. Kind regards, Eike

-- Ehj52N - 04 Nov 2016

You could make a static WebList topic ... Main.CommonWebsList and then %INCLUDE it in place of the System.WebLeftBarWebsList. But this still means editing every WebLeftBar topic.

A quick solution (we do not recommend!) is to simply update the WebLeftBarWebsList topic. It avoids changing ever WebLeftBar, but you would lose your changes the next time you upgrade foswiki.

The problem with the WEBLIST macro has been well known, but there isn't really a good solution for it. In order to generate a weblist, the Foswiki core must:
  1. Read every WebPreferences file to check if the current user can view the web,
  2. Read every WebHome to check if the current user can view the topic.
And since it's in the WebLeftBar, this happens for every page view in your wiki. A lot of webs means a lot of auth checking. If you use the PageCache, then it means that every cached topic has a dependency on every WebHome and WebPreferences topic in your wiki.

Unfortunately no matter how you look at it, it's an expensive feature.

-- GeorgeClark - 04 Nov 2016

Best would be to remove the WEBLIST from the sidebar and have the list of all available webs on the frontpage. Anyway, each topic will always depend on the preference system reading required WebPreferences along the rendering path. There is not much we can do about this fact other than ignoring dependencies partially ... which could result in caching errors, of course (stale content that should have been rendered differently due to content changes).

There are other inefficiencies in the page caching code that we won't be cleaning up until after 2.1.3 has been released.

Let's please keep these performance issues aside from the original report made here. Is there any more insight in what caused topcis and webs getting wrong access rights sporadically, Ehj52N? Or is it in fact related to the page cache being activated or not?

-- MichaelDaum - 12 Dec 2016

Setting this task to No Action - No feedback, and no further reports. Please reopen if the problem can be reproduced.

-- GeorgeClark - 18 Feb 2017

ItemTemplate edit

Summary Random topics or webs get access restricted
ReportedBy Ehj52N
Codebase 2.1.2
SVN Range
AppliesTo Engine
Priority Urgent
CurrentState No Action Required
WaitingFor Ehj52N
TargetRelease n/a
ReleasedIn n/a
Topic revision: r9 - 18 Feb 2017, GeorgeClark
The copyright of the content on this website is held by the contributing authors, except where stated elsewhere. See Copyright Statement. Creative Commons License    Legal Imprint    Privacy Policy