* * * * *
                                        
  The end result was a computer producing vast amounts of nothing very slowly
                                        
So, I run this loadtest program on my work computer. It's going, I can see
the components I'm testing registering events (via the realtime viewer [1] I
wrote for syslogintr [2]). Everything is going fine … and … … then … … … t …
h … e … … c … o … m … p … … u … … … t … … … … e … … … … … r … … … … … … … … s
… … … … … … … … … … l … … … … … … … … … … … … … … … o … … … … … … … … … … … …
w … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … s …

It takes about ten minutes to type and run, but this:

> [spc]saltmine:~>uptime
>  14:44:20 up 6 days, 23:12, 10 users,  load average: 2320.45, 1277.98, 546.61
> 

was quite amusing to see (usually the load average is 0). Perhaps it was just
a tad ambitious to simulate 10,000 units on the work computer (each unit its
own thread, running a Lua script [3]—yes, even after the modifications to the
Lua interpreter [4]).

Also amusing was this:

> [spc]saltmine:~>free
>              total       used       free     shared    buffers     cached
> Mem:       3910888     640868    3270020          0      35568     185848
> -/+ buffers/cache:     419452    3491436
> Swap:     11457532     544260   10913272
> 

Yes, eleven gigabytes of memory were shoved out to the disk, so most of the
slowless was due to thrashing [5].

Perhaps I should find some fellow cow-orker's computer to run this on …

[1] https://github.com/spc476/syslogintr/blob/master/realtime.lua
[2] https://github.com/spc476/syslogintr
[3] gopher://gopher.conman.org/0Phlog:2013/03/22.2
[4] gopher://gopher.conman.org/0Phlog:2013/03/23.1
[5] http://en.wikipedia.org/wiki/Thrashing_(computer_science)

Email Sean Conner at sean@conman.org

.