[Systems] Wiki unresponsive

[Chris Ball]

Hi,

   > I'm starting from assumption that Mediawiki wouldn't become
   > intermittently unresponsive on its own, because PHP applications
   > are mostly stateless. So I'm looking for external causes first,
   > starting from those causing most activity.
   > 
   > Was there any change to your tinderbox that could explain the
   > increase in I/O and CPU load we're seeing?

No change from me -- it's still being started with "nice ionice -c2
-n6" -- but the number of modules built per run is dependent on the
number of modules buildable, which fluctuates over time as compile
errors are fixed.  There have been some compile errors fixed recently,
so an increase in load (back to a previous level) makes sense.

   > Another thing to investigate is the sudden increase in MySQL
   > queries.  Since there's no corresponding increase in web traffic,
   > I'd tend to exclude web applications. What else is using MySQL on
   > solarsail?

I don't know (and can't check because I don't have root anymore).
Tinderbox doesn't use MySQL.

   > Analyzing intermittent performance issues from remote is hard, we
   > may never know for sure. Tinderbox may or may not be the cause,
   > it's just on the list of suspects until we can exclude it for
   > sure.

This is a good argument for belief in God, but a poor argument for
examining evidence.  :)  You can turn off (if it's even running) the
tinderbox any time you want to check whether it's the cause of an
outage.

- Chris.
-- 
Chris Ball   <cjb at laptop.org>
One Laptop Per Child