I noticed running some Drupal admin tasks if they take usually more then 10 seconds result in a 404 error. For example, I was running "Search and replace" and it always throws a 404 after about 10 seconds even though the task apparently works.
I only noticed this after migrating my Drupal install to Dreamhost. I've increased the max_execution time in php.ini but that didn't help. Is there a way to get Drupal to output the error?
Apache Error log:
[Wed Jun 30 09:00:18 2010] [error] [client 12.105.246.2] (104)Connection reset by peer: FastCGI: comm with server "/.../cgi-bin/dispatch.fcgi" aborted: read failed, referer: .../admin/content/scanner/scan/confirm
[Wed Jun 30 09:00:18 2010] [error] [client 12.105.246.2] FastCGI: incomplete headers (0 bytes) received from server "/.../cgi-bin/dispatch.fcgi", referer: .../admin/content/scanner/scan/confirm
[Wed Jun 30 09:00:38 2010] [error] [client 12.105.246.2] (104)Connection reset by peer: FastCGI: comm with server "/.../cgi-bin/dispatch.fcgi" aborted: read failed
[Wed Jun 30 09:00:38 2010] [error] [client 12.105.246.2] FastCGI: incomplete headers (0 bytes) received from server "/.../cgi-bin/dispatch.fcgi"
UPDATE Turns out this was a hosting problem with DreamHost. On their basic shared hosting Drupal was hitting their resource/memory limit and getting processes killed. I had to move the hosting to a Dreamhost VPS (PS) as a workaround.