Monday, June 11

Geek

Got It!

Finally tracked down what's going on on the production web servers.

The system automatically flushes the cache when you update a page, so people don't get old copies of the page.  That's timing out - it eventually happens, but it takes more than ten seconds, so the reverse proxy times out and returns a "System not available" error.  Since the cache flush is handled by the redirect module (which all update pages have to call), you never receive the redirect because the proxy closes the connection first.

It was particularly confusing because (a) the updates actually worked and (b) because the error was inside the redirect module and redirect logging was at the start of the redirect module, the log files showed that the redirect was happening but no browser request was following it.

And the reason for that is that (a) I didn't have a local cache running and (b) the remote cache is blocked by the firewall.  It seems that cache lookups time out immediately, but cache flushes take much longer.

Which should have been obvious.

Posted by: Pixy Misa at 12:32 PM | No Comments | Add Comment | Trackbacks (Suck)
Post contains 180 words, total size 1 kb.

Comments are disabled. Post is locked.
40kb generated in CPU 0.03, elapsed 0.1692 seconds.
50 queries taking 0.152 seconds, 280 records returned.
Powered by Minx 1.1.6c-pink.