* * * * *
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 author at
[email protected]