What t1.micro CPU Bursting Looks Like
Amazon’s smallest and least expensive instance type, the t1.micro “provide[s] a small amount of consistent CPU resources and allow[s] you to burst CPU capacity when additional cycles are available. [It is] well suited for lower throughput applications and web sites that consume significant compute cycles periodically.” (source)
Running a cpu-bound workload (building Perl modules) on an Ubuntu 11.10 t1.micro instance in us-west-2 tonight, I noticed the following curious CPU usage pattern of approximately 15 seconds on, 60 seconds off:
> vmstat 5 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 0 38528 29524 370540 0 0 86 423 84 216 12 5 35 4 1 0 0 6800 30288 388856 0 0 5356 26 660 1433 27 27 6 40 5 0 0 21752 27624 378088 0 0 30 211 150 159 40 22 0 8 6 0 0 21256 27636 378104 0 0 0 27 9 7 1 1 0 0 7 0 0 21256 27644 378108 0 0 0 10 9 9 1 1 0 0 7 0 0 21256 27652 378112 0 0 0 8 9 9 2 1 0 0 7 0 0 20256 27652 378228 0 0 0 0 8 13 1 1 0 0 8 0 0 20016 27660 378072 0 0 0 218 15 29 0 2 0 3 6 0 0 37884 27672 378048 0 0 0 14 9 11 3 1 0 0 4 0 0 30808 27684 378048 0 0 0 11 9 10 1 1 0 0 4 0 0 23740 27692 378056 0 0 0 10 8 8 2 1 0 0 4 0 0 30676 27692 378104 0 0 0 0 10 10 1 1 0 0 5 0 0 26220 27700 378064 0 0 0 9 7 14 6 2 0 1 5 0 0 21012 27712 378120 0 0 0 10 9 10 1 0 0 0 5 0 0 27336 27720 378064 0 0 0 21 13 10 1 1 0 0 1 0 0 29444 27732 378064 0 0 0 14 149 97 39 19 0 0 1 0 0 33420 27744 378084 0 0 6 12 250 166 67 30 0 0 2 0 0 41108 27756 378100 0 0 0 37 207 148 60 29 0 0 6 0 0 33668 27768 378068 0 0 0 14 8 9 1 1 0 0 5 0 0 37008 27780 378068 0 0 0 10 10 15 4 1 0 0 4 0 0 30808 27788 378072 0 0 0 18 11 9 2 0 0 0 5 0 0 24360 27796 378092 0 0 0 9 8 7 2 0 0 0 2 0 0 19896 27796 378140 0 0 0 0 8 9 1 1 0 0 6 0 0 27584 27804 378152 0 0 0 7 8 12 1 1 0 0 6 0 0 22864 27812 378148 0 0 0 9 10 12 2 1 0 0 7 0 0 19136 27820 378152 0 0 0 10 8 9 1 1 0 0 6 0 0 26096 27828 378148 0 0 0 12 10 7 2 1 0 0 6 0 0 20640 27828 378156 0 0 0 19 13 8 2 1 0 0 6 0 0 27956 27836 378156 0 0 0 11 9 12 1 1 0 0 6 0 0 22864 27844 378156 0 0 0 6 9 12 2 1 0 0 6 0 0 19020 27844 378156 0 0 0 1 9 9 1 1 0 0 2 0 0 46896 21504 368588 0 0 518 18 261 291 47 29 1 7 1 0 0 35372 21692 368788 0 0 0 43 253 174 65 32 0 0 1 0 0 43060 21796 368600 0 0 0 62 149 112 66 32 0 1 5 0 0 38100 21808 368600 0 0 0 46 11 10 1 1 0 0 5 0 0 45788 21816 368592 0 0 0 7 8 12 2 1 0 0 7 0 0 38464 21816 368600 0 0 0 0 7 8 2 1 0 0 7 0 0 45912 21824 368596 0 0 0 11 9 9 2 1 0 0 7 0 0 39216 21832 368600 0 0 0 7 9 8 1 0 0 0 4 0 0 35496 21840 368596 0 0 0 19 11 9 4 1 0 0 5 0 0 43060 21848 368600 0 0 0 29 10 10 2 1 0 0 5 0 0 37480 21856 368592 0 0 0 11 9 10 1 1 0 0 5 0 0 45044 21864 368596 0 0 0 7 9 10 1 1 0 0 5 0 0 38340 21872 368600 0 0 0 8 8 8 2 1 0 0 4 0 0 46284 21880 368596 0 0 0 10 10 11 1 1 0 0 6 0 0 38836 21888 368592 0 0 0 8 8 8 2 1 0 0 1 0 0 38340 21888 368544 0 0 0 15 53 41 12 7 0 0 1 0 0 40828 21900 368568 0 0 2 46 255 218 66 33 0 0 1 0 0 39960 21912 368608 0 0 0 26 237 153 63 28 0 0 3 0 0 50632 21924 368540 0 0 0 16 58 44 32 15 0 0 4 0 0 46284 21932 368540 0 0 0 7 8 11 1 1 0 0 4 0 0 45400 21940 368540 0 0 0 6 9 10 1 1 0 0 5 0 0 45292 21948 368552 0 0 0 11 8 14 0 1 0 0 6 0 0 37720 21948 368584 0 0 0 17 12 6 2 1 0 0
Apparently, the “small amount of consistent CPU resources” is about 3% of the CPU.
Moral of the story for me? Next time, pay the big bucks and launch an m1.small spot instance.
Thinking Sysadmin 