Cache, which is commonly used to make sites load faster, also causes problems in web browsers, but Link Map Viewer creates a much more serious situation.
Link Map Viewer doesn't like cache
It is common to see that page of site has been modified, but it is not reflected when viewed in web browser, or that file is replaced but still old when downloaded. Both are problems that occur because information before updating is kept in cache.
Link Map Viewer makes this worse. Link Map Viewer will incrementally generate link map each time when updating to avoid time-consuming rebuilding. Link Map Viewer relies on site map's update date and time for that task. The sitemap has the last modified date and time for each page (sitemaps without this type are not supported), but if this is different from the known one, it is determined that page has been updated. Here are some possible problems:
- If cache is keeping old sitemap, Link Map Viewer won't even notice that page has been updated in the first place.
- Link Map Viewer reads updated sitemap and notices page has been updated, but it may read cached old page. This causes terrible situation. Clearing cache won't let Link Map Viewer re-read that page, link map stays old.
Depending on site, there may be two types of caches, one for the CMS (for example, WordPress plugin) and the other for server. In this case clearing CMS's cache is not enough and server's cache will produce very annoying issue.
Note that Link Map Viewer does not use cache (per Windows application) when accessing the web.
Clear cache before updating
Showing old cached data to Link Map Viewer causes trouble, in case cache may be doing this, you should clear cache before updating link map. Cache made by plugins can be cleared with simple operation. Procedure to clear server-side cache may be more tedious and frustrating. But turning off server-side cache is not a good idea.
Bypass server-side cache for Link Map Viewer
Some web server has option to bypass server-side cache for given user agent. Link Map Viewer's user agent name is "LinkMapViewer". You can specify this name if your web server supports this feature. This is highly recommended.
Re-Read page and refresh node
Clicking right mouse button on node and select "Re-Read page and refresh node" in context menu makes app re-read page as it is updated and update link map. This comes handy in case modified page is not reloaded due to cache issue, to force Link Map Viewer re-read that single page.
If app is still showing old data after doing that, it's likely that cache is still keeping old page.
Rebuilding
Pressing "Rebuild" button on upper right of screen dump currently held link map data and start rebuilding from scratch. So it will take some time. This is an option as a last resort when you can't make app work well or you think cache is causing issue and want to recover from this bad situation even it takes long.
Note that rebuilding won't by-pass cache so please clear cache first.