Newest changes only appear when logged in

A forum for new users, and for old users to greet the new ones
Bruce Michez
Posts: 2
Joined: 26 May 2018 07:43

Newest changes only appear when logged in

Postby Bruce Michez » 26 May 2018 07:59

Yesterday, I posted some scores on CPDL for the first time. I also created the works' pages and composer page myself. All very well, except that as soon as I logged out, they all disappeared, along with everything else that people posted during that time. They also disappeared from "Most recent scores" on the main page.

I know that other logged-in users can see them, because an administrator changed the capitalization of the titles for consistency.

I also tried using a different browser. This time the main page listed my submissions, but following the links consistently led to blank pages.

Is it intentional that people who aren't logged in, only see a days-old version of the entire site? What is going on here?

choralia
Site Admin
Posts: 2619
Joined: 05 Mar 2006 19:57
Location: Rome, Italy
Contact:

Re: Newest changes only appear when logged in

Postby choralia » 27 May 2018 15:24

Choralwiki is based on the Mediawiki software, which is the same used by other websites like Wikipedia, or, in the music field, IMSLP.

The Mediawiki software includes a relatively aggressive caching mechanism. To save server resources, only logged-in users receive the latest version of a page. Anonymous users receive a cached page instead. Cached pages expire in a couple of days, so the cached version of a page becomes identical to the latest version after some delay. However, as pages are not edited very frequently, only a small number of pages appear different to anonymous users versus logged-in users.

This mechanism is a little bit emphasized by the specific server architecture we have at CPDL. To ensure that the library cannot be lost even in the case of catastrophic failures at server farms (e.g., earthquakes, floods, etc.), and in ordert to maintain server costs affordable with respect to our budget, we currently have a main "contributor" server (http://www.cpdl.org) for logged-in users, and 4 "visitor" servers (www0.cpdl.org; www1.cpdl.org; www2.cpdl.org; www3.cpdl.org) for anonymous users. They are all placed in geographically separated locations. The contributor server is a Virtual Private Server, while visitor servers are very inexpensive shared servers. Visitor servers are daily aligned to the contributor server, typically between 08:00 and 09:00 GMT. This also causes a delay between the time when a modification is made on the contributor server, and the time when the modification is visible to anonymous users.

Pages locally cached on the user's computer may cause further delay, which is out of our control. My experience is that Safari is the most stubborn browser as far as displaying locally cached pages is concerned.

While receiving cached pages is pretty normal, receiving blank pages is anomalous. Please let us know which visitor server (www0, www1, www2, www3) is showing this problem. We are currently receiving some intermittent system warnings from www3, yet to be investigated.

Max

Bruce Michez
Posts: 2
Joined: 26 May 2018 07:43

Re: Newest changes only appear when logged in

Postby Bruce Michez » 28 May 2018 08:47

I rather think it was www3, but I'm not certain.


Return to “New members meeting place”

Who is online

Users browsing this forum: No registered users and 1 guest