Imported huge webs and get Internal Server Errors

1. You are using fcgi and dbcachecontrib
2. You just imported a (few) huge web(s)
3. You try to view a simple topic and fail with an Internal Server Error
4. You apache error log shows

[Fri May 06 01:03:48 2011] [warn] [client 1.2.3.4] mod_fcgid: read data timeout in 40 seconds, referer: https://my.box/Hugeweb/WebHome
[Fri May 06 01:03:48 2011] [error] [client 1.2.3.4] Premature end of script headers: foswiki.fcgi, referer: https://my.box/Hugeweb/WebHome

Answer

When you touch/view a topic from an freshly imported web for the first time, DBCacheContrib (re)builds its caches in working/work_areas/DBCacheContrib. This takes some time. More than fcgi usually has.

Do the following according to the Installation Instructions:

1. Before installing DBCachePlugin, disable your web server.
2. Install the plugin.
3. Go to foswiki-dir/bin and call ./rest /DBCachePlugin/updateCache to index all webs for the first time.
4. Enable the web server again.

Disabling the web server is a good practice as otherwise a bunch of concurrent requests all trigger an index rebuild each. Once the index has been build for the first time it will be updated automatically during a normal save or upload.